MXPA00007081A - Process for increasing the melt strength of polypropylene - Google Patents

Abstract

A process for modifying a polypropylene (co)polymer wherein said process comprises melt mixing the polypropylene (co)polymer in the presence of an initiator wherein said initiator is selected from the group defined by formula (1), wherein R is selected from the group consisting of optionally substituted C1 to C18 acyl, optionally substituted C1 to C18 alkyl, aroyl defined by formula (2), and compounds of formula (3), wherein U, V, X, Y, Z, U', V', X', Y'and Z'are independently selected from the group consisting hydrogen;halogen;C1-C18 alkyl;C1-C18 alkoxy, aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, aryloxycarbonyl, trialkyl silyl, hydroxy, or a moiety of formula (4), and wherein T is alkylene.

Description

PROCESS FOR I NCREMENTING THE PROPI LINE FUSION FORCE The invention relates to homopolymers and polypropylene copolymers. In particular, the present invention relates to a process for increasing the melting strength and / or the melting viscosity of said polymers by melt phase processing.

The melting strength and extension viscosity of linear or straight chain polymers, such as polypropylene, decreases rapidly with temperature. In contrast, polymers such as low density polyethylene, which are highly branched, retain relatively high melting forces and viscosities. In general, it is understood that the difference in melting forces and extension viscosities can be attributed to the presence of long chain branching in polymers, such as, low density polyethylene. The long chain branching allows a greater degree of string entanglement. A variety of methods have been proposed to increase the melting strength / extension viscosity of polypropylene and related polymers ugh the introduction of branching or a limited degree of crosslinking in a process involving reactive extrusion, and are summarized in a document. recent by Wang et al. (Wang, X., Tzonganakis, C, and Rempel, G.L., J. Appl. Polym, Sci., 1 996, 61, 1 395). One such process involves the reactive extrusion of polypropylene with a combination of polyfunctional monomer / initiator. For example, the use of pentaerytol tr acrylate in combination with 2,5-dimethyl-2,5-di (t-butiiperoxy) hexane (DHBP).

White (US 5578682) has discovered the use of various polyunsaturated crosslinking agents (for example, bismaleimide derivatives) in combination with free radical initiators to achieve an increase in the melting strength of various polymers. It is well known that the melt phase processing of polypropylene leads to mechanochemical degradation. The processing of polypropylene in the presence of free radical initiators provides an increased degradation ratio. This controlled degradation of polypropylene is commercially used for the production of controlled rheology resins having reduced polydispersity and reduced die swelling (Lambia, M. in Comprehensive Polymer Science, Pergamon, New York 1992, vol.Sup.1, p.619; Hogt, AH, Meijer, J., Jelinic, J. in Reactive Modifiers for Polymers, Al-Malaika, S. Ed., Chapman &Hall, London, 1996, p. 84). The degradation of polypropylene, as described herein, results in a decrease in the melting force. The batch modification of polypropylene to produce cross-linked polypropylene (insoluble) by treatment with peroxides is described by Borsig et al. (Borsig, E. Fiedlerova, A., Lazar, M.J., Macromol.Sci, Chem., 1981, A16, 513). Initiators that produce benzoyloxy radicals or phenyl radicals are described as more efficient for inducing cross-linking or grafting than those which produce alkyl or t-butoxy radicals. The process requires the use of high levels of peroxide. The use of polyfunctional monomers as coagents to retard degradation and enhance crosslinking is described by Chodak, I.; Fabianova, K.; Borsig, E.; Lazar, M. Agnew. Makromol Chem. , 1978, 69, 1 07.

DeNicola (EP 384331 A2) has described a means for producing a branched propylene polymer material showing a net increase in the weight average molecular weight by solid state modification of semi-crystalline, predominantly isotactic linear polypropylene. The process described in EP384331A2, involves mixing peroxides with short half-lives (eg, peroxy dicarbonates) with linear propylene polymer in a mixing vessel at temperatures from 23 ° C to 1 20 ° C in an inert atmosphere and continuing to mix for a period of time until the peroxide decomposes and polymer fragmentation and branching occur without gelation of the polymer. DeNicola states that at temperatures greater than 1 20 ° C no intensification of fusion strength or branching is achieved. The U.S. 5, 464,907 shows that certain unsaturated taconate or maleate-derived peroxides can be used to induce grafting in α-olefin and polypropylene copolymers. It reports that the use of other peroxides, usually results in chain degradation. It is also known that polypropylene undergoes substantial degradation during the melt phase grafting of monofunctional monomers, for example, maleic anhydride and glycidyl methacrylate. It has also been reported that the degradation accompanying the grafting of these monomers to polypropylene can be reduced by the addition of relatively high concentrations of certain comonomers including styrene (see, for example, Sun, Y.-J., Hu, G. -h., and Lambía, M., Angew, Makromol, Chem., 1995, 229, 1; Chem, L-F. , Wong, B. and Baker, W. E. Polym. Eng. Sci. 1996, 36, 1594.). Sun et al. they report that there is degradation (as indicated by a global decrease in molecular weight), when styrene is only grafted onto polypropylene even when a relatively high concentration is used (4 mol / 1000 g PP). • 2, 5-Dimethyl-2,5- (t-butyl peroxy) hex-3-ino or 2,5-dimethyl-2,5- (t-butylperoxyhexane (DHPB) was used as the initiator in These experiments We have found that the fusion mixture of polypropylene homopolymer or ethylene-polypropylene copolymer, in the presence of a suitable initiator, provides one or more of the following: increased fusion; increased extension viscosity; weight • Increased molecular • and extended molecular weight distribution. In accordance with the present invention, there is provided a process for modifying a polypropylene (co) polymer, wherein said process comprises melt mixing the polypropylene (co) polymer in the The presence of an initiator, wherein said initiator is selected from the group defined by formula 1: Formula 1 wherein R is selected from the group consisting of optionally substituted d to C18 acyl, optionally substituted d to C18 alkyl, aroyl defined by formula 2, Formula 2 and groups of formula 3, Formula 3 wherein U, V, X, Y, Z, U \ V, X ', Y' and Z 'are independently selected from the group consisting of hydrogen, halogen, C 1 -C 8 alkyl, C 1 -C 1 alkoxy 8, aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, aryloxycarbonyl, trialkyl silyl, hydroxy, or a portion of formula 4, Formula 4 and where T is alkylene. Advantageously, the modified polypropylene thus formed can be obtained without the associated production of significant and deleterious amounts of gels. Polymers suitable for use in the present invention include a wide variety of homopolymers, polypropylene copolymers and blends containing one or more polypropylene homopolymers and / or copolymers. Suitable polypropylene homopolymers include isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene. Preferably, commercial isotactic polypropylene having a meso / diadate ratio of more than 90% is used in the process of the present invention. Isotactic polypropylene is a semi-crystalline polymer that has a variety of properties, which have made it one of the most widely used commercial polymers. These properties include heat resistance, resistance to stress cracking, chemical resistance, hardness and low manufacturing costs. However, the fusion strength of the isotactic polypropylene, as measured directly by extension viscosity, or use of a commercial melt strength tester, or indirectly by more qualitative measures, such as, decay time or die swelling ratio , it is relatively low. This relatively low melting force limits the use of polypropylene in applications, such as foam extrusion, thermoforming and film blowing. In order to use polypropylene in such applications, it is necessary to employ sophisticated processing equipment. The present invention now allows this commercial polymer, already widely used, to be used in an even wider range of applications. The polypropylene copolymers include copolymers of propylene and other monomers, those other monomers being present in amounts of up to 10% w / w. A preferred comonomer is ethylene. The present invention is also applicable to other polymers comprising α-olefin monomers. It is preferable that such α-olefins are present in the polymer to be modified in amounts in excess of 90% w / w. The α-olefins include propene, 1-butene, 1-pentene and 1 -hexene. The primers for use in the present invention can be selected from the group defined by formula 1.

Formula 1 wherein R is selected from the group consisting of optionally substituted acyl of d to C18, optionally substituted alkyl of d to C? 8, aroyl defined by formula 2, Formula 2 and groups of formula 3, Formula 3 wherein U, V, X, Y, Z, U \ V, X ', Y' and Z 'are independently selected from the group consisting of hydrogen, halogen, C 1 -C 8 alkyl, C 1 -C 1 alkoxy , aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, aryloxycarbonyl, trialkyl silyl, hydroxy, or a portion of formula 4, Formula 4 and where T is alkylene. Alkyl groups, including acyl and alkoxy, included in the initiators of formula 1, may include heteroatoms within the carbon chain (e.g., polyalkylene oxide) and may be branched or unbranched, and may be substituted with one or more groups, such as with, alkyl, aryl, alkoxy or halogen substituents.

Without wishing to join a theory, it is believed that the aroyloxy radical of formula Formula 5 where U, V, X, Y and Z are as defined above, they provide the surprising increase in fusion strength. Other compounds that generate these aroyloxy radicals in the present invention can also be used. A preferred class of initiators of formula 1 are diaryrole peroxides of formula 6.

Formula 6 where X, Y, Z, U, V, X ', Y', Z ', U', V are independently selected from the group consisting of hydrogen and alkyl of dC 8, where at least one of X, And, Z, U, V and X ', Y', Z ', U', V is not hydrogen. The diaryl peroxides of formula 6 include dibenzoyl peroxide, o, o'-bis (methylbenzoyl) peroxide, p-peroxide, p'-bis (methylbenzoyl), M peroxide, M'-bis (methylbenzoyl), peroxide or, m'-bis (methylbenzoyl), o-peroxide, p'-bis (methylbenzoyl), m-peroxide, p'-bis (methylbenzoyl), bis (ethylbenzoyl) peroxide (all isomers), bis peroxide ( propylbenzoyl) (all isomers), bis (butylbenzoyl) peroxide (all isomers), bis (pentylbenzoyl) peroxide (all isomers), bis (hexylbenzoyl) peroxide (all isomers), bis (heptylbenzoyl) peroxide (all isomers), bis (octylbenzoyl) peroxide (all isomers), bis (nonylbenzoyl) peroxide (all isomers), bis (methoxybenzoyl) peroxide (all isomers), bis (ethoxybenzoyl) peroxide (all isomers), bis (propoxybenzoyl) peroxide (all isomers), bis (butoxybenzoyl) peroxide (all isomers), bis (pentoxy) peroxide benzoyl) (all isomers), bis (hexyloxybenzoyl) peroxide (all isomers), bis (heptioxybenzoyl) peroxide (all isomers), bis (octyloxybenzoyl) peroxide (all isomers), bis (nonyloxybenzoyl) peroxide (all isomers), bis (chlorobenzoyl) peroxide (all isomers), bis (fluorobenzoyl) peroxide (all isomers), bis (bromobenzoyl) peroxide (all isomers), bis (dimethylbenzoyl) peroxide (all isomers), bs (trimethylbenzoyl) peroxide (all isomers), bis (tert-butylbenzoyl) peroxide (all isomers), bis (di-tert-butylbenzoyl) peroxide (all isomers), peroxide bis (terbutoxybenzoyl) (all isomers), bis (ditrimethyl silyl benzoyl) peroxide (all isomers), bis (heptafluoropropylbenzoyl) peroxide (all isomers), bis (2,6-dimethyl-4-trimethylsilyl benzoyl peroxide) ) and isomers, dibutyl ester of 2,2 '(dioxydicarbonyl) bis-benzoic acid, where The term "all isomers" refers to any variation in the position of the ring substituent, as well as the structure of the substituent itself, ie, for propyl; n-propyl and isopropyl. Examples of aromatic peresters of formula 1 include the following: tert-butyl perbenzoate, tert-butyl (methyl) perbenzoate (all isomers), tert-butyl (ethyl) perbenzoate (all isomers), (octyl) perbenzoate tert-butyl (all isomers), tert-butyl (nonyl) perbenzoate (all isomers), ter-amyl perbenzoate, ter-amyl (methyl) perbenzoate (all isomers), terpene (ethyl) perbenzoate amyl (all isomers, (octyl) perbenzoate of ter-amyl (all isomers), (nonyl) perbenzoate of ter-amyl (all isomers), (methoxy) perbenzoate of ter-amyl (all isomers), (octyloxy) ) ter-amyl perbenzoate (all isomers), (nonyloxy) ter-amino perbenzoate (all isomers), 2-ethylhexyl perbenzoate, methyl ethyl (methyl) perbenzoate (all isomers), 2-ethylhexyl (ethyl) perbenzoate (all isomers), (octyl) 2-ethylhexyl perbenzoate (all isomers), 2-ethylhexyl (all isomers), (nonyl) perbenzoate, 2-ethylhexyl (all isomers), (methoxy) perbenzoate, 2-ethylhexyl (ethoxy) perbenzoate (all isomers), 2-ethylhexyl (octyloxy) perbenzoate (all isomers, (Nonyloxy) 2-ethylhexyl perbenzoate (all isomers). Initiators for use in the present invention also include compounds of formula 1, wherein at least one of U, V, X, Y, Z, U ', V, X', Y 'and Z', is a portion of formula 4 , where R is as defined above. Preferably, there is no more than one portion of formula 4 per aromatic ring. Such initiators are diperoxides or major functional peroxides, and may include polymeric peroxides, such as diperoxy terephthalate of bis (tert-butylmonoperoxy phthaloyl), diperoxy terephthalate of bis (teramylomonoperoxy phthaloyl), diacetyl phthaloyl dioperoxide, dibenzoyl phthaloyl dioperoxide , bis (4-methylbenzoyl) phthaloyl-diperoxide, diacetyl-terephthaloyl-diperoxide, dibenzoyl-terephthaloyl-diperoxide, poly [dioxycarbonyldioxy (1,1,4,4-tetramethyl-1,4-butanediyl)] peroxide]. It is described that the initiators are selected so that they have an appropriate decomposition temperature (half-life), solubility, and reactivity and such that the groups R, T, X, Y, Z, U, V, X ', Y' , Z ', U', V do not give an adverse reaction under the conditions of the process. The preferred peroxides will have a half-life of 0.1 hour in the range 100 ° C - 170 ° C. The amount of initiator used - in the process of the present invention should be an amount effective to achieve the desired increase in melting strength. Fusion strength is considered in the art as an indication of the long chain branching in polyolefins. It is preferable in the process of the present invention, that long chain branching predominates over crosslinking in the reaction between the initiator and the polypropylene (co) polymer. The crosslinking of the polypropylene (co) polymer can result in the formation of gels, which breaks the appearance of the polypropylene (co) polymer. In the process of the present invention, it is desirable to control the degree and distribution of crosslinking, and to maintain the level of crosslinking as uniform and as low as necessary to produce the desired effects. The amount of crosslinking that occurs in the polypropylene (co) polymer is dependent on the amount of initiator melt mixed with the (co) polypropylene polymer. The amount of crosslinking is also dependent on the degree of mixing since any region high in initiator concentration will result in excessive localized crosslinking and gel formation. It is desirable that good distributive and dispersive mixing be employed to promote a uniform distribution of the initiator in the (co) polypropylene polymer, in order to minimize the variation in the concentration of the initiator along the (co) polypropylene polymer. and reduce the likelihood of gel formation. Preferably, the initiator will be present in the range from 0.004 to 0.25 moles of initiator per kg of the polypropylene homopolymer or copolymer (polypropylene (co) polymer), the most preferred range being from 0.006 to 0.10 moles of initiator per kg of (co) polypropylene polymer and the most preferred range being from 0.01 to 0.05 moles of initiator per kg of the polypropylene (co) polymer.

The initiator is preferably introduced into the polymer melt directly, either pure (as a powder or a liquid), dispersed or dissolved in a suitable medium (for example, dissolved in 2-butanone), or adsorbed on pellets of polymer or powder, which are added as a master batch. It is desirable that the initiator be rapidly mixed with the polymer melt at a ratio to maintain the half-life of the initiator at the polypropylene (co) polymer processing temperature. The initiator can be added either alone, or together with the polypropylene (co) polymer, or with any other polymer, additive or filler, so that the polymer melts and mixes with the initiator as it decomposes. When the initiator is fed to the main feed throat of the extruder, it is preferred that it has a barrel temperature, which is relatively low in the region adjacent to the main feed throat and increases towards the die to prevent premature decomposition of the peroxide. . Preferably, the initiators for use in the present invention are selected from the group consisting of dibenzoyl peroxide, o-peroxide, o'-bis (methylbenzoyl), p-peroxide, p'-bis (methylbenzoyl), o -peroxide, o'-bis (methylbenzoyl), o-peroxide, m'-bis (methylbenzoyl), o-peroxide, p'-bis (methylbenzoyl), m-peroxide, p'-bis (methylbenzoyl), bis peroxide ( ethylbenzoyl) (all isomers), bis (propylbenzoyl) peroxide (all isomers), bis (butylbenzoyl) peroxide (all isomers), bis (pentylbenzoyl) peroxide (all isomers), bis (hexylbenzoyl) peroxide (all isomers), bis (heptylbenzoyl) peroxide (all isomers), bis (octylbenzoyl) peroxide (all isomers), bis (nonylbenzoyl) peroxide (all isomers), bis (methoxybenzoyl) peroxide (all isomers), bis (ethoxybenzoyl) peroxide (all isomers), bis (propoxybenzoyl) peroxide (all isomers), hydrogen peroxide, is (butoxybenzoyl) (all isomers), bis (pentoxybenzoyl) peroxide (all isomers), bis (hexyloxybenzoyl) peroxide (all isomers), bis (heptyloxybenzoyl) peroxide (all isomers), bis peroxide ( octyloxybenzoyl) (all isomers), bis (nonyloxybenzoyl) peroxide (all isomers), bis (chlorobenzoyl) peroxide (all isomers), bis (fluorobenzoyl) peroxide (all isomers), bis (bromobenzoyl) peroxide (all isomers), bis (dimethylbenzoyl) peroxide (all isomers), bis (trimethylbenzoyl) peroxide (all isomers), bis (tert-butylbenzoyl) peroxide (all isomers), bis (di-) peroxide tert-butylbenzoyl) (all isomers), bis (tert-butoxybenzoyl) peroxide (all isomers), bis (ditrimethylsilylbenzoyl) peroxide (all isomers), bis (heptafluoropropylbenzoyl) peroxide (all isomers), bis peroxide ( 2,4-dimethyl-6-trimethylsilyl benzoyl) and isomers per ter-amyl benzoate, ter-amyl (methyl) perbenzoate (all isomers), ter-amino (all isomers), (nonyl) perbenzoate, ter-amyl (methoxy) perbenzoate (all isomers), (octyloxy) ) ter-amyl perbenzoate (all isomers), ter-amyl (nonyloxy) perbenzoate (all isomers), bis (teramylmonoperoxy phthaloyl) diperosi terephthalate, diacetyl phthaloyl diperoxide, dibenzoyl phthaloyl dioperoxide, diperoxide bis (4-methylbenzoyl) phthaloyl, diacetyl terephthaloyl peroxide and dibenzoyl terephthaloyl diperoxide. More preferably, the initiators are selected from the group consisting of dibenzoyl peroxide, o-peroxide, o'-bis (methylbenzoyl), p-peroxide, p'-bis (methylbenzoyl), M peroxide, M'-bis (methylbenzoyl) ), o, o'-bis (methylbenzoyl) peroxide, o-peroxide, p'-bis (methylbenzoyl), m, p'-bis (methylbenzoyl) peroxide. Optionally, the initiators can be used in combination with one or more monomers. Preferably, one or more monomers are selected from the group consisting of monoene monomer. Those skilled in the art will understand that by the term "monoene monomer" is meant a monomer having a single reactive double bond. The preferred monoene monomer (s) or mixtures thereof include vinyl monomers of structure CH2 = CHX, where X is chosen in order to confer the desired reactivity and solubility. The most preferred monomers include styrene. The amount of monomer will preferably be up to 5 times the total moles of initiator added to the (co) polypropylene polymer. The most preferred range is 1 to 4 times the total moles of initiator added to the (co) polypropylene polymer. The monomer can be added with the polypropylene (co) polymer, or it can be added before the initiator, with the initiator or subsequent to the initiator. However, it is preferred to have the monomer mixed and dispersed in the polymer melt before the initiator has substantially decomposed. The monomer is preferably introduced into the polymer melt directly, either pure (as a powder or a liquid), dispersed or dissolved in a suitable medium (for example, dissolved in 2-butanone), or adsorbed on pellets or polymer powder, which are added as a master batch. Preferred initiators to be used, in combination with the monomers, include dibenzoyl peroxide, o, o'-bis (methylbenzoyl) peroxide, p-peroxide, p'-bis (methylbenzoyl), M peroxide, M'-bis ( methylbenzoyl), o-peroxide, m'-bis (methiibenzoyl), o-peroxide, p'-bis (methylbenzoyl), m-peroxide, p'-bis (methylbenzoyl), bis (etylbenzoyl) peroxide (all isomers), bis (propylbenzoyl) peroxide (all isomers), bis (butylbenzoyl) peroxide (all isomers), bis (pentylbenzoyl) peroxide (all isomers), bis (hexylbenzoyl) peroxide (all isomers) , bis (heptylbenzoyl) peroxide (all isomers), bis (octylbenzoyl) peroxide (all isomers), bis (nonylbenzoyl) peroxide (all isomers), bis (methoxybenzoyl) peroxide (all isomers), peroxide of bis (ethoxybenzoyl) (all isomers), bis (propoxybenzoyl) peroxide (all isomers), bis (butoxybenzoyl) peroxide (all isomers), bis (pentoxybenzoyl) peroxide (all isomers), bis (hexyloxybenzoyl) peroxide (all isomers), bis (heptyloxybenzoyl) peroxide (all isomers), bis (octyloxybenzoyl) peroxide (all isomers) ), bis (noniloxibenzoyl) peroxide (all isomers), bis (chlorobenzoyl) peroxide (all isomers), bis (fluorobenzoyl) peroxide (all isomers), bis (bromobenzoyl) peroxide (all isomers), bis (dimethylbenzoyl) peroxide (all isomers), bis (trimethylbenzoyl) peroxide (all isomers), bis (tert-butylbenzoyl) peroxide (all isomers), bis (di-tert-butylbenzoyl) peroxide (all isomers), bis (tert-butoxybenzoyl) peroxide (all isomers), bis (ditrimethylsilylbenzoyl) peroxide (all isomers), bis (heptafluoropropylbenzoyl) peroxide (all isomers), bis (2,4-dimethyl) peroxide 6-trimethylsilyl benzoyl) and isomers, dibutyl ester of acid 2,2 '(dioxydicarbonyl) bis-benzoic acid, tert-butyl perbenzoate, tert-butyl (methyl) perbenzoate (all isomers), tert-butyl (ethyl) perbenzoate (all isomers), (octyl) perbenzoate), tert-butyl (all isomers), tert-butyl (nonyl) perbenzoate (all isomers), ter-amyl perbenzoate, ter-amyl (methyl) perbenzoate (all isomers), terpene (ethyl) perbenzoate amyl (all isomers, (octyl) perbenzoate of ter-amyl (all isomers), (nonyl) perbenzoate of ter-amyl (all isomers), (methoxy) perbenzoate of ter-amyl (all isomers), (octyloxy) ) ter-amyl perbenzoate (all isomers), termino (nonyloxy) perbenzoate (all isomers), 2-ethylhexyl perbenzoate, 2-ethylhexyl (methyl) perbenzoate (all isomers), (ethyl) perbenzoate) of 2-ethylhexyl (all isomers), 2-ethylhexyl (octyl) perbenzoate (all isomers), 2-ethylhexyl (nonyl) perbenzoate (all isomers), 2-ethylhexyl (methoxy) perbenzoate) (all isomers), 2-ethylhexyl (all isomers), (ethoxy) perbenzoate, 2-ethylhexyl (octyloxy) perbenzoate (all isomers, 2-ethylhexyl (nonyloxy) perbenzoate (all isomers), diperoxy terephthalate) of bis (tert-butyl monoperoxy phthaloyl), diperoxy terephthalate of bis (teramylomonoperoxy phthaloyl), diacetyl phthaloyl dioperoxide, dibenzoyl phthaloyl dioperoxide, bis (4-methylbenzoyl) phthaloyl-diperoxide, diacetyl-terephthaloyl diperoxide, dibenzoyl terephthaloyl dioperoxide, poly [dioxycarbonyldioxy (1,1,4,4-tetramethyl-1,4-butanediyl)] peroxide]. Advantageously, the initiators can be selected to avoid undesirable by-products. In certain applications, it may be desirable to avoid the use of initiators, which generate benzene. For example, di toluoyl peroxides (bis methyl benzoyl peroxides) can be used, preferably for dibenzoyl peroxide. The processing capacity and other properties of the by-product can be improved by a chain scission step following the initial polymer modification step. This can be done by: a) adding one or more additional initiators with, or subsequent to, the first initiator addition; b) the use of high cut mixing; c) the use of high temperatures; d) the combination of use is one or more of (a) - (c) above. This additional step in the production of a polymer enables the adjustment of the properties of the product to meet the requirements of the desired application. For example, by means of this two-stage process it is possible to produce materials with melt viscosity similar to the base polymer, but a substantially increased melting force. The use of the simple stage process generally provides both an increase in melting strength and an increase in melt viscosity (see examples). One or more additional initiators can be added to the polypropylene (co) polymer during the modification process, either with or subsequent to, the addition of initiator and monomer. The additional initiator is usually added to provide chain cleavage of the polypropylene (co) polymer, in order to lower the melt viscosity and improve the processability of the modified polypropylene (co) polymer. The additional initiator should be introduced into the polymer melt after the first initiator, or it should have a sufficiently long half-life relative to the first initiator, so that its decomposition can be prepared to occur after the initial polymer modification process . In some cases, a modified polypropylene (co) polymer according to the present invention may have an MFl < 1 g / 1 0 min. With the use of the additional initiator, an MFl < 1 g / 10 min. The additional initiator can be selected from the group consisting of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (DHBP), dicumyl peroxide (DCP), t-butyl peroxy-2-ethylhexonate (TBEH) ), and dilauryl peroxide (DLP), or any other peroxide, which may result in the overall chain cleavage of the polypropylene (co) polymer during fusion processing. For example, in the absence of the monoene monomers, t-butyl peroxybenzoate or other non-preferred initiators to be used in the presence of the monomer, they can preferably be added as the additional initiator. Although the improvement in processing capacity through chain scission normally results in some decrease in the melting strength / extension viscosity of the modified polypropylene (co) polymer, the melting strength / viscosity of extension may still be acceptable, and can be improved over the unmodified polypropylene (co) polymer. It is possible to combine the process of the present invention with other polymer modification processes or with, for example, the addition of fillers, additives or stabilizers, or mixed with other polymers, [which do not interfere substantially with the improved properties provided by the process of the present invention]. In the process of the present invention, the polypropylene (co) polymer is melt-mixed in the presence of initiator and monomer. The melt mixing can be carried out by any convenient means capable of mixing the polypropylene (co) polymer at temperatures above the melting point of the polypropylene (co) polymer. Suitable apparatuses for melt blending the polypropylene (co) polymer include continuous and batch mixers. Suitable mixing equipment includes extruders, such as single screw or twin screw extruders, static mixers, cavity transfer mixers and combinations of two or more thereof. It is preferred that the melt blending be conducted either in a co-or counter-rotating twin screw extruder.

The barrel setting temperatures are preferably in the range of 80-280 ° C. Normal melting temperatures are in the range of 170-290 ° C. In order to optimize the melting strength / extension viscosity, the preferred melting temperatures are in the range of 160 ° C to 220 ° C. This range provides optimal properties while minimizing the amount of chain scission, which occurs during processing. However, in some cases, it may be desirable to use higher temperatures, such as, in the ventilation / discharge sections of single screw or twin screw extruders, or to induce some chain scission in order to decrease the molecular weight of the (co) modified polypropylene polymer and improve the processing capacity of the modified polypropylene (co) polymer.

Normally, the die temperatures are in the range of 180-290 ° C. Preferably, the extrusion conditions are adjusted so that the polypropylene (co) polymer, initiator / monomer mixture, is transported as fast as possible to the melting / mixing zone to maximize the melting phase reaction ( for example, for twin screw extruders - high efficiency ratios, higher screw speeds under power failure conditions). It is more preferred that the additives be added to, and mixed with, molten polypropylene (co) polymer to further enhance the melt phase reaction. Preferably, residence times in the range from 10 seconds to 5 minutes are selected depending on the temperature profile, yield ratio and initiator levels. Residence times in the range of 1 5 seconds to 1 20 seconds are more preferred. Vacuum ventilation can be applied to remove volatile byproducts, solvents and / or excess monomer. While not wishing to be limited to one theory, it is believed that the effectiveness of the present invention is determined by three factors: (a) The rate and specificity of reaction of the aroyloxy or the phenyl derivative radicals or substituted phenyl radicals with polypropylene, and the monomer if present. It is believed that the substituted aroyloxy, phenyl or aroyloxy or phenyl radicals, show less specificity for tertiary hydrogen subtraction vs. secondary or primary than the one shown, for example, by alkoxy or alkyl radicals. (b) The average life of the initiator. The use of an initiator with a short half-life of initiator will generate a locally high concentration of radicals, thus increasing the likelihood of radical combination cases. (c) The solubility characteristics of the initiator in the polymer melt.

Without wishing to join a theory, peroxides producing aroyloxy or aryl radicals (eg, benzoyloxy, p-toluouloxy) are preferred over those which generate alkoxy radicals (eg, t-butoxy radical, cumyloxy radical). It is believed and supported in the literature that the last class of peroxides promotes chain cleavage under the conditions of fusion mixing. Although it is not desired to bind to a mechanism, it is believed that this effect is due to the specificity shown by the alkoxy radicals, as opposed to the aroyloxy or aryl radicals generated by the peroxides of structure 1. In addition, we believe that peroxides that generate both alkoxy and aroyloxy or aryl radicals (eg, t-butyl perbenzoate), show intermediate behavior. It is believed that they promote less chain cleavage than peroxides that generate only alkoxy radicals (e.g., dialkyl peroxides) when used alone, and can be used to aid in systems where a monomer coagent is employed. The preferred peresters are, in this manner, those which generate alkoxy radicals which are not active in subtraction of hydrogen (for example, t-amyl perbenzoate). Similarly, it is believed, without wishing to unite a theory, that the effectiveness of the monomer is determined by: (a) The solubility of the monomer in the polymer melt. For example, it is known that styrene is soluble in molten polypropylene. (b) The reactivity of the monomer towards polypropylene-derived radicals. (c) The propensity for the radical formed by addition of monomer to give combination or addition (which leads to branching or crosslinking) vs. disproportionate or subtraction of hydrogen. It is known that benzylic radicals provide predominantly combination and have a low tendency (relative to other radicals) to subtract hydrogen. Other initiators and monomers that meet the above criteria may also be used to aid in the present invention. Surprisingly, the process of the present invention results in a polypropylene (co) polymer with substantially increased melting strength. We have found that it is possible to obtain, with the present invention, a polypropylene (co) polymer, which has a melting strength of at least 25% greater than the melting strength of the base polymer. We have also found that it is possible to obtain an increase in melting strength of more than 100% for a number of the polypropylene (co) polymers produced according to the process of the present invention. Increases in the strength of fusion were evaluated using a Gottfert-Rheotens fusion strength tester operated with a roller acceleration of 1 .2 cm / s2, measuring the fusion strength of a 2 mm filament of polypropylene (co) polymer melted (melting temperature of 210 ° C), which is fed to the Gottfert tester at ~ 4 g / min.

In a further aspect of the present invention, there is provided a (co) modified polypropylene polymer produced according to the process described herein, wherein said modified polypropylene (co) polymer preferably has a melting force of at least 25%, and more preferably at least 100% , greater than the unmodified polypropylene (co) polymer. The polypropylene (co) polymers produced according to the process of the present invention can also provide a significant increase in long chain branching. The long chain branching can be assessed using the Dow Rheology index. Advantageously, the modified polypropylene (co) polymers can demonstrate a Dow Rheology Index (DRI) of more than 1, preferably of at least 2 and most preferably greater than 50.

The process of the present invention can also be used to increase the melt elasticity of a polypropylene (co) polymer. Advantageously, the process of the present invention also provides a means for altering the molecular weight, molecular weight distribution and / or branching grade and length of polypropylene, ethylene-propylene copolymers, and analogous α-olefin copolymers with or without altering the fusion force of said polymers by melt processing. The process of the present invention can provide a means for generally increasing the molecular weight and expanding the molecular weight distribution and / or introducing branches of the polypropylene (co) polymer. This is not always equal to significant increases in the melting strength or viscosity of extension of the polymer that is being modified, for example, modification of a lower molecular weight polymer to expand the molecular weight, and / or induce shorter chains. Such a product can not necessarily demonstrate a high melting strength, but can demonstrate other desirable properties, for example, enhanced filler capture, mechanical properties, surface properties, thermal and morphological properties. The modified polypropylene (co) polymer produced by the process of the present invention can be used either neat or mixed with another polymer or other additives to provide the desired balance of properties in the polymer blend. Modified polypropylene (co) polymers and blends can be used in a wide variety of applications including thermoforming, blow molding, tube or pipe extrusion, blown films, foams and extrusion coating. The present invention can also be used in the recycling of waste polypropylene or waste polypropylene containing materials. The increased melting strength of the modified polypropylene (co) polymers makes these (co) polymers more suitable for use in thermoforming applications. The modified polypropylene (co) polymers can be used to thermoformer containers, such as margarine tubes. The benefits of this invention include that the polypropylene (co) polymers and mixtures thereof, provide a wider temperature processing window than conventional isotactic polypropylene. Modified polypropylene (co) polymers can also be used in large part thermoforming, such as in the production of refrigerator coatings and the like, where conventional isotactic polypropylene is not suitable.

The modified polypropylene (co) polymers produced in accordance with the present invention are suitable for blow molding and we have found that they can be blow molded more easily into containers. Additionally, the increased melting force makes it possible to produce large blow molded parts through the use of the high melt strength modified polypropylene (co) polymer. In this way, the components currently made by rotational molding can now be produced by blow molding., using the modified polypropylene (co) polymer of the present invention. It has been found that profile extrusion, eg tube or pipe extrusion, using the modified polypropylene (co) polymer, produces a more consistent product than conventional isotactic polypropylene. Blown films made of polypropylene are generally blown down using relatively expensive equipment. The modified polypropylene (co) polymers of the present invention have sufficient melting strength to be capable of being blown up using conventional polyethylene type film blowing equipment, which is less expensive and is generally more convenient to operate. Advantageously, the modified polypropylene (co) polymers of the present invention can be used in the production of blown films. The modified polypropylene (co) polymers of the present invention can also be foamed with a broader processing window than for conventional polypropylene. A blowing agent, either physical or chemical, can be used. It is preferred to use carbon dioxide as a physical blowing agent to produce foams having a fine structure of closed cells. The foamed pellets can be subsequently molded to form components for use in a variety of applications, such as automotive interior door finishes, roof linings, dashboard, fenders and the like. Applications are also possible, such as, in foam packaging, including thermoformed containers, insulating cups and the like. Waste polypropylene or waste streams containing a significant proportion of polypropylene are currently difficult to recycle, since conventionally a high degree of chain splitting results from the recycling process. The process of the present invention can be used to improve recycled streams containing polypropylene by increasing the overall mechanical properties of the recycled polypropylene by the addition of initiator and monomer according to the present invention. The present invention will now be described with reference to the following non-limiting examples. The measurement techniques used in the examples and a complete description of the process conditions employed are described herein. The Comparative Examples are marked CE-n.

Melt Strength Measurement Melt forces were measured in a "Rheotens" Fusion Strength Tester, Type 010.1, supplied by Gottfert Werkstoff-Prufmaschinen Gmbh of Buchen, Germany. This test involves dragging an extruded polymer filament vertically towards the bite between two counter-rotating bite rollers. The filament was extruded using a Brabender Plasticord single screw extruder with a diameter of 1 9 mm and a length-to-diameter ratio (L / D) of 25. The extrudate exited via a right-angle capillary die (diameter 2). mm).

The temperature profile used was uniform along the length of the barrel of the extruder and the die, and was adjusted to 190 ° C. The bite rollers are mounted on a balance arm, which allows to measure the force in the filament that is being dragged. The speed of the bite rollers is increased to a uniform acceleration rate. As the test proceeds, the force increases until the filament eventually breaks. The force in the break is called the "fusion force". Although there is no internationally established standard set of test requirements for fusion strength test, the comparative melting strength values obtained under the given set of test conditions provide a quantitative determination of the increase in the strength of fusion used in the patent . The test conditions used were: die temperature 190 ° C, extruder exit velocity ~ 4 g / min, acceleration ratio 1.2 cm / s2, drag distance 210 mm, steel rollers with matt finish.

Dow's Relogue Index In the art it is believed that the Dow Rheology Index (DRI) is a measure of the long chain branching in a polymer. It is expressed as the deviation of a viscosity parameter obtained from the rheology measurements of cut in a "branched" polymer, compared with those for a linear polymer. The branched polymers have lower values of the viscosity parameter than the linear polymers (for a given relaxation parameter). The parameters are obtained by adjusting the Cross model to the cut viscosity flow curves. The DRI method has been described by Lai, Plumley, Butler, Knight and Kao in a document in SPE ANTEC '94 Conference Proceedings (pp1814-1 81 8) - "Dow Rheology Index (DRI) for I nsite Technology Polyolefins (ITP) : Unique Structure-Processing Relationships "(Dow's rheology index (DRI) for insite technology polyolefins (ITP): unique structure-processing relationships).

Dynamic rheology tests Dynamic rheology tests were performed on a Rheometrics SR200 dynamic tension rheometer. The test conditions were: parallel plates, temperature 190 ° C, frequency range 0.01 to 100 rad / s, and 3-4% distension, in a nitrogen atmosphere to prevent degradation. G 'is the storage module that represents the elasticity of the polymer melt, G "is the loss modulus, which represents the viscous component of the deformation.The polydispersity index is 1 0 for energy 5 divided by the modulus of crossing, which is the value of G '= G ", when the curves G' and G" are crossed - it is believed to be a measure of MWD.The greater the G ', the greater the elasticity in the polymer and the higher the MW.

Mfi The melt flow rates (MFl) were measured at 230 ° C with a load of 2.16 kg according to ASTM 1 238.

Fall Times Fall times were determined by measuring the time taken for the polypropylene filament (cut on the face of the die) to fall from the die of the extruder to the floor. The die of the double screw extruder JSW was 1 140 mm above the floor. The drop time test combines the effects of melt viscosity, extension viscosity, chain entanglement (as shown by die swelling), and elasticity (as shown by the tendency to resist neck formation). Polypropylene polymers with higher melt viscosity had decay times that incorporated some additional effect due to prolonged cooling of the molten filament moving (falling) slower.

GPC The GPC molecular weights were determined using a Waters 150C high temperature GPC unit. 1, 2,4-trichlorobenzene was used as the solvent, levigating through two linear columns of Styragel HT6E. The furnace temperature was adjusted to 140 ° C and the flow rate of the pump was 1.0 ml / min. The calibration was performed using narrow polydispersity polystyrene standards. All molecular weights were cited as polystyrene equivalents. Mn = number average molecular weight Mw = weight average molecular weight Mz = viscosity average molecular weight Mp = peak molecular weight Double screw extruder The double screw extruder used in the examples was a JSW TEX- • 5 30 with a screw diameter of 30 mm and a total L / D of 42 [comprising ten barrel sections of controlled temperature (L / D 3. 5, temperatures between 120 and 230 ° C as specified in Table 1), three unheated sampling / monitoring blocks (L / D 1 .167) and a cooled feed block (L / D 3.5)), equipped with two feeders gravimetric JSW TTF20, a gravimetric additive feeder K-Tron • KQx and a volumetric liquid addition pump (Fuji Techno Industries model HYM-03-08)]. The extruder was operated either in co-rotary mode (self-cleaning filter), or counter-rotating (without self-cleaning intermalla), with a yield ratio between 5 and 20 kg / h and speeds of screw between 100 and 400 rpm as specified in Table 1. The melting temperature and pressures were monitored at three points along the barrel and on the die.

Table 1 . Operating conditions Conditions Velocity of Temperature profile (° C) screw (rpm) feed (kg / h) A 265 20 150 ° C, 175 ° C (for 10) B 265 20 180 ° C, 200 ° C ( by 3), 220 ° C (by 7) 150 120 ° C, 130 ° C (by 4), 180 ° C (by 6) D 265 20 140 ° C, 150 ° C (by 10) 265 20 180 ° C , 200 ° C (by 4), 230 ° C, 240 ° C, 250 ° C, 260 ° C, 270 ° C, 280 ° C. F 400 20 180 ° C, 220 ° C (for 10) G 265 20 80 ° C, 120 ° C, 140 ° C, 160 ° C, 170 ° C, 180 ° C, 200 ° C (for 5) H 150 80 ° C, 120 ° C, 140 ° C, 160 ° C, 170 ° C, 180 ° C, 190 ° C (for 3), 200 ° C (for 2) 265 20 80 ° C, 120 ° C, 140 ° C, 160 ° C, 170 ° C, 180 ° C, 190 ° C (for 3), 200 ° C (for 2) 250 20 150 ° C, 170 ° C (for 3), 180 ° C, 200 ° C, 220 ° C (by 5) • The temperatures in the table refer to sections of the extruder barrel that are capable of independent temperature control.

The first ten temperatures are barrel section temperatures and the last temperature indicates the temperature of the die.

Table 2 - Die configuration Condition Die description 1 Large 3-hole filament die - 6 mm holes 2 Small 3-hole filament die - 4 mm holes 3 Large 2-hole filament die - 6 mm holes 4 Single hole Brabender die - 10 mm hole Table 3 - Means of addition of modifier Condition Description of die a Modifier added in block 4 in solvent carrier of 2-butanone Modifier added in block 4 in solvent carrying xylene Modifier coated on powder PP - pre-mixed in drum Modifier coated on PP master powder batch The global extruder configuration and modifier conditions can be declared, for example, as a condition: A1 d.

Addition with solvents of modifiers The initiator, and the monomer if present, were introduced as a solution in 2-butanone or xylene. The concentration of the initiator ranged from 5.6% w / w to 8.5% w / w. The benzoyl peroxide and the di-toluol peroxides were both powders moistened with 25% or (w / w) of water. The monomer was present in an amount of between 4 to 10% w / w of solvent. Increased levels of initiator were generally added by increasing the amount of solution added to the polymer melt. Additional peroxides (if any) were added with the initiator in the carrier solvent.

Addition without solvents of modifiers T-butyl peroxybenzoate is a liquid. Solvent-free modification of the polymer was achieved by absorbing the developer into polymer powder or mixing it with polymer powder at concentrations ranging from 5% w / w to 10% w / w to form a master batch. The master batch was added to the extruder at varying feed rates to alter the amount of additives. The amount of polymer feed was adjusted according to a constant overall feed rate. The stabilizers were also added as a master batch. The amount of stabilizer was generally kept constant at 0.33%) weight / weight of Irganox 1010 and 0.1 7% weight / weight of Irgaphos 1 68 in the total composition.

The main polymer feed was added either as powder or pellets.

Killion Single Screw Extruders The Killion single screw extruder used in the examples was a simple segmented screw extruder of L / D = 40 (1 1 barrel sections, 10 heated) and screw diameter of 31 .75 mm. The polypropylene powder, stabilizers (0.33%) weight / weight of Irganox 1 01 0, 0.1 7% w / w of Irgaphos 168 in total) and the developer, were added to the feed throat of the single screw extruder via a K-Tron double screw volumetric feeder. Alternatively, the polypropylene powder and stabilizers were added via the K-Tron feeder and the polypropylene powder, stabilizers and modifiers were added as a masterbatch via an APV Accurate single screw volumetric feeder. The masterbatch contained 7.5% w / w of benzoyl peroxide (prepared using a dispersion of benzoyl peroxide containing 25% w / w of water). The output of the extruder was -1.5 kg / h using a screw speed of 30 rpm. The adjusted barrel temperature was either (i) a 220 ° C plane with each section of barrel and die set at a temperature of 220 ° C, or (ii) 230 ° C / 190 ° C with the first six sections of barrel melting set at 230 ° C and the following four barrel and die measuring sections set at 1 90 ° C. The melting temperature varied from 220 to 260 ° C.

Brabender The single screw extruder Brabender used was a single screw extruder of L / D = 25 (4 barrel sections), 2.5: 1 compression ratio and 1 9 mm screw diameter. The die was a 4 mm bar die. The screw speed of the extruder was 20 rpm. The adjusted barrel temperature was 140 ° C, 1 70 ° C, 1 80 ° C. Residence time: start 3 min 40 s; center 4 min 35 s; and final 7 min 30 s. The polypropylene powder, either with criomolide pellets or excretory dust, was mixed with the modifiers and added to the feed throat, either by flood feed or by a single-screw Brabender volumetric feeder. The following commercial polypropylene (co) polymers were used in the examples. The properties of the (co) polymers are shown in Table 4 below.

Table 4: Comparative data for a PP grade of high melting strength and conventional PP grades. Example Polymer Description of MFl 2. 1 6 kg Polymer strength @ 230 ° C fusion cN Control 1 Montell PF814 Homopol 1 8 high melting strength polypropylene Control 2 Montell Homopol JE61 00 number polypropylene extrusion grade Control 3 ICI Australia Degree of molding by 14 1 .8 GYM 45 injection of polypropylene homopolymer Control 4 I CI Australia Extrusion grade of 2.8 GWM 22 Polypropylene homopolymer Control 5 ICI Australia Grade of 0.8 PXCA 61 52 thermoformed polypropylene homopolymer Control 6 ICI Australia Degree of molding by 14 1 .4 LYM 120 injection of propylene / ethylene copolymer Control 7 Montell Ex-reactor grade 4.1 6501 of homopoly injection molding polypropylene number Control 8 Montell Extrusion grade of -3.5 KM61 00 Montell Control Polypropylene Homopolymer Extrusion grade of -3.5 KMT61 00 homopoly Polypropylene Montell Control Montell Grade ex-reactor -3.5 10 KM61 00 of non-stabilized polypropylene homopolymer powder * The fusion strength and MFl were measured for a particular lot and we have found that the actual values vary up to 20% of these values.

Examples 1 to 5 GYM45 was modified according to Table 5 below. GYM45 is a low molecular weight injection molding polypropylene homopolymer / MFI higher.

Table 5: Example Conditions BPO (% Styrene Current Temp. MFl Time 2.16 Weight force) (% in given motor (° C) drop (s) kg @ melt weight) (amp) 230 ° C (cN) Control - - 0 - - - 14 1.8 3 CE 1 B1a 0 0 13 231 8 12.2 1.5 1 B1a 0.36 0 13 229 9.7 14.4 1.9 2 B1a 0.7 0 13 229 13.5 14.4 2.3 3 B1a 0.95 0 13 230 17.1 12.5 3 4 D3a 1.0 0 19 197 23 9.7 4 D4a 0.34 0.45 21 179 22.9 9.1 6.9 Example 6 to 18 GWM22 was modified in accordance with Table 6. GWM22 is a polypropylene homopolymer of intermediate molecular weight / medium MFI extrusion grade.

Table 6: Example Conditions BPO (% Styrene Current Time Temp. MFl 2.16 Weight force) (% in given motor (° C) drop (s) kg @ melt weight) (amp) 230 ° C (cN) Control 4.5 2.8 4 CE 2 B1a 0 0 16 239 11.3 5 - 6 B1a 0.36 0 16 234 15.2 6.3 3 7 B1a 0.75 0 17 238 21.8 5.9 4.7 8 B1a 1 0 16 239 25.4 5 6.9 9 B1a 1.3 0 20 236 25.3 5.6 7.1 B1a 0.12 0.13 16 237 8.0 4.15 - 11 B1a 0.23 0.31 17 237 11.2 2.8 5 12 B1a 0.46 0.61 21 238 14 1.11 - 13 B1a 0.69 0.92 21 241 14.2 0.69 18.6 14 B1a 1.22 1.63 21 248 - - 18.6 E1a 0.33 0.44 17 281 20 3.6 8.2 16 C2a 0.81 4.2 18 203 60 0.69 18.8 17 E1a 0.31 0.40 20 275 23 3.1 7.0 '18 E1a 0.30 0.53 17 277 • 24 3.4 9.1 The increase in complex viscosity of examples 14, 15, 17 and 1 8 is shown in Figure 1. G 'has been plotted against the frequency in Figure 2.

The modified polypropylenes of the examples were tested for additional physical properties, and it was found that the modified polypropylenes had: 14 16 17 18 Control 4 i) Elasticity rad / s 1200 680 40 45 10 G'@0.01 rad / s (Pa) (pa) ii) 1 / time of -0.001 0.085 15 18 23 Frequency of relaxation 3 crossing (rad / s) iii) index of 222 39 4.4 AJÍ 3.7 Mw / Mn polydispersity • iv) rheology index 192 86 2.0 5.6 0 Branch d of Dow long chain Examples 1 9 to 26 PXCA61 52 was modified according to Table 7 below. PXCA6152 is a polypropylene homopolymer of high molecular weight / low thermoforming grade MFl • 10 Table 7: Example Conditions BPO (% Styrene Current Time Temp. MFl 2.16 Weight force) (% in given motor (° C) drop (s) kg @ melt weight) (amp) 230 ° C (cN) Control 0.8 6 CE 3 F1a 0 0 17 251 14.6 1.1 - 19 B1a 0.34 0 22 244 25.9 1.3 7.4 B1a 0.38 0 23 250 22.8 1.1 11.1 21 B1a 0.8 0 24 246 30.5 0.8 14 22 B1a 1.04 0 24 247 25.3 0.65 17.7 23 F1a 0.31 0.41 21 256 24.4 0.42 17.5 24 F1a 0.47 0.63 21 264 25 0.31 - 25 F1a 0.55 0.73 23 269 - 0.40 - 26 F1a 0.71 0.95 22 259 25 0.35 21.3 The modified polypropylene of Example 22 was tested for additional physical properties and it was found that the modified polypropylene had: i) Elasticity 200 G '@ 0.01 rad / s (Pa) ii) 1 / relaxation time 7.1 Crossover frequency (rad / s) iii) polydispersity index 3.0 Mw / Mn iv) Dow rheology index 10 Chain branching Long It was expected that the DRI of the base polypropylene material, PXCA 61 52 (an unbranched polypropylene) would be 0. The DRI of the modified polypropylene demonstrates a significant degree of long chain branching.

Examples 27 to 33 LYM 1 20 was modified according to Table 8 below. LYM 1 20 is a PP copoiimer of injection molding grade of low molecular weight / M FI higher.

Table 8: Example BPO Conditions (% Styrene Current MFl Time Temp 2.16 Weight Force) (% in given motor (° C) drop (s) kg @ melt weight) (amp) 230 ° C (cN) Control 12.2 1 .4 6 27 D2a 0.68 0 1 3 182 19.3 13.1 2.3 28 A4a 1 .08 0 1 9.5 200 31 9 4.2 29 A2a 0.33 0.44 1 8 202 28 5.8 7.4 D2a 0.32 0.42 23 185 46.5 3.8 9.0 31 A4a 0.42 0.55 1 9.5 204 31.1 6.5 11.2 32 A4a 0.62 0.83 20 201 36.8 - 11.9 33 A4ß 0.34 0.45 16 199 25.1 _ 4.3 Examples 34 to 42 The ex-reactor powder GYM45 was modified according to Table 9 below. GYM45 is a low molecular weight / MFI injection molding grade polypropylene homopolymer. The polypropylene was stabilized with Irganox 1 010 (0.33% by weight) and I rgaphos (0.17% by weight). The modifiers and stabilizers were added to the twin screw extruder in the feed throat.

Table 9: Example Conditions BPO (% Styrene Current Time Temp. MFl 2.16 Strength in weight) (% in given motor (° C) drop (s) kg @ melt weight) (amp) 230 ° C (cN) Control - - - - - - 14 1.8 3 CE 4 H3d 0 0 7 209 21.5 11.3 1.7 34 I3d 0.38 0 14 209 12.1 13.6 1.9 36 I3d 0.75 0 15 210 15.0 11.8 2.6 37 I3d 1.5 0 15 214 20.6 10.3 5.7 38 H3d 0.75 0 6 209 35.5 17.6 2.1 39 H3d 1.13 0 8 208 39.5 13.3 2.9 40 H3d 1.5 0 8 208 43.3 9.8 4.4 41 I3d 0.15 0.2 18 216 16.6 9.6 2.0 42 I3d 0.23 0.3 16 214 20.5 6.5 5.5 Examples 43 to 49 GYM45 was modified in accordance with Table 10 below. GYM45 is a low molecular weight / MFI injection molding grade polypropylene homopolymer.

Table 10: Example Conditions Initiator Initiator Styrene Current Temp Time MFl 2.16 (% in (% in given motor (° C) drop (s) kg @ weight) weight) (amp) 230 ° C CE 5 A3a - 0 0 18 192 11.8 12.8 43 A3a BPO 0.12 0.16 16 197 14 14.4 44 A3a BPO 0.21 0.28 17 200 18.8 9.8 45 A3a BPO 0.41 0.55 20 206 27.6 5.6 46 A3a BPO 0.62 0.83 22 208 32.2 3.6 CE-6 A3a DHBP 0.33 0.09 14.5 191 4.6 55 CE-7 A3a DHBP 0.60 0.17 16 190 4 117 CE-8 A3a DHPB 0.90 0.28 14.5 190 3.9 132 CE-9 A3a TBEH 0.33 0.34 16 191 9.9 18.3 CE-10 A3a TBEH 0.60 0.62 17 192 10 19.5 CE-11 A3a TBEH 0.90 0.93 17 193 10.6 17.2 47 A3a TBPB 0.30 0.30 15 194 7.8 58.3 48 A3a TBPB 0.68 0.70 17 198 14 47.3 49 A3a TBPB 0.89 0.91 19 199 15.6 38.5 CE-12 A3a DCP 0.08 0.09 14.5 192 4.3 48.5 CE-13 A3a DCP 0.17 0.17 15 191 3.9 67.7 CE-14 A3a DCP 0.25 0.25 15 191 3.7 90.3 CE-15 A3a DLP 0.33 0.33 15 190 11.2 16.5 CE-16 A3a DLP 0.63 0.64 15 190 11.1 15.1 CE-17 A3a DLP 0.92 0.93 15 190 11.1 18.0 Examples 50 to 54 LYM120 was modified in accordance with Table 11 below. LYM120 is a low molecular weight / MFI injection molding grade polypropylene copolymer.

Table 11: Example BPO conditions (% Current MFl Temp. Time 2.16 Weight force) of given motor (° C) dropped (s) kg @ fusion (amp) 230 ° C (cN) ontroI 12.2 1.4 6 CE 18 H3d 0 7 209 18.4 11.3 1.2 52 H3d 0.75 8 210 50.5 6.9 2.6 53 H3d 1.13 8 210 47.0 6.6 3.3 54 I3d 1.5 14 217 18.5 3.8 6.1 Examples 55 to 61 LYM 120 was modified according to Table 12 below. LYM 1 20 is a low molecular weight injection molding grade polypropylene copolymer / higher MFI.

Table 1 2: Example CondicioIniciador Iniciador Estireno Current of Time Temp MFl 2.16 kg Force nes (% in (% in motor (amp) given (° C) of fall @ 230 ° C of fusion weight) weight) (s) (cN ) CE-1 9 A3a BPO (LOO OTÓO 16 195 9.9 12.8 1.1 55 A3a BPO 0.12 0.16 15 197 13.9 10.9 56 A3a BPO 0.21 0.28 7.5 201 17.7 7.50 11.5 57 A3a BPO 0.41 0.55 20 208 25.8 4.4 58 A3a BPO 0.62 0.83 21 209 26.5 2.9 CE-20 A3a DHBP 0.08 0.09 1 3.5 1 91 4.9 52 CE-21 A3a DHBP 0. 16 0.17 14 190 5.3 79 CE-22 A3a DHBP 0.28 0.30 14.5 190 5.6 1 14 CE-23 A3a TBEH 0.31 0.32 14 192 8.6 17.8 CE-24 A3a TBEH 0.62 0.64 14 192 9 17.4 CE-25 A3a TBEH 0.98 1.01 14 192 9.6 15.4 • 59 A3a TBPB 0.30 0.31 14 196 4.6 33.8 60 A3a TBPB 0.61 0.62 17 200 14.6 32.9 61 A3a TBPB 0.93 0.95 17 202 15.6 23.1 CE-26 A3a DCP 0.08 0.09 13 192 5 38.6 CE-27 A3a DCP 0.1 7 0.17 13.5 190 5.5 57.6 CE-28 A3a DCP 0.27 0.28 14 190 6.2 65.9 CE-29 A3a DLP 0.31 0.31 15 191 9.9 15.7 CE-30 A3a DLP 0.64 0.65 13.5 190 9.8 14.8 CE-31 A3a DLP 1.00 1.01 13 190 14.8 Examples 62 to 73 LYM120 was modified according to Table 13 below. LYM120 is a low molecular weight / MFI injection molding grade polypropylene copolymer.

Table 13: Example Condicio- Initiator Starter Styrene Temp Time Current MFl 2.16 kg Force (% in (% in motor (amp) given ("C) of fall @ 230 ° C of melting weight) weight) (s) (cN) CE-32 A3d 14.5 200 10 12.4 1.1 62 A3d BPO 0.11 0 14 199 10 11.5 1.1 63 A3d BPO 0.23 0 16.5 201 15.1 9.0 1.2 64 A3d BPO 0.45 0 16.5 203 20.6 6.6 1.7 65 A3d BPO 0.68 0 17.5 206 20.6 5.4 4.1 66 A3d BPO 1.13 0 18 206 18.6 5.7 3.9 CE-33 A3d DLP 0.31 0 13.5 198 9.3 13.6 CE-34 A3d DLP 0.59 0 14 199 8.8 14.4 CE-35 A3d DLP 0.89 0 13 196 8.9 15.0 CE-36 A3d TBPB 0.07 0 12 189 5.1 28.7 CE-37 A3d TBPB 0.1 5 0 12 190 5.3 31.0 - CE-38 A3d TBPB 0.29 0 10.5 185 6.3 92.0 0.5 CE-39 A3d TBPB 0.59 0 11 186 11.2 102.0 - 67 A3d BPO 0.1 1 0.15 17.5 205 19.1 5.7 2.4 68 A3d BPO 0.23 0.30 19.5 210 25 4.3 6.3 69 A3d BPO 0.45 0.6 21.5 209 27.8 2.1 10.4 70 A3d BPO 0.90 1.2 23.5 210 26.8 1.3 12.2 CE-40 A3d DLP 0.30 0.3 14.5 199 9.4 14.1 - CE-41 A3d DLP 0.59 0.6 13 197 9.3 17.2 - CE-42 A3d DLP 0.89 0.9 13 197 9.8 16.1 - 71 A3d TBPB 0.29 0.3 13.5 196 11.4 20.4 3.7 72 A3d TBPB 0.59 0.6 16.5 200 20.2 12.9 - 73 A3d TBPB 1 .18 1.2 17 202 18.8 13.9 4.5 Examples 74 to 77 GYM45 was modified according to Table 1 3 below. GYM45 is a low molecular weight / MFI injection molding grade polypropylene homopolymer.

Example Conditions Starter Initiator (% Current MFl Time Temp 2.16 kg by weight) of given motor (° C) drop (s) @ 230 ° C (amp) CE-43 A3a - 0 Í8 1 92 1 1 .8 1 2.8 74 A3a BPO 0.23 1 6.5 1 96 10.35 17.0 75 A3a BPO 0.45 17 199 11.8 17.3 76 A3a BPO 0.73 17 200 15.9 15.4 77 A3a BPO 0.96 18 202 17.3 14.9 CE-44 A3a DHBP 0.08 15 191 3.6 96 CE-45 A3a DHBP 0.17 14.5 190 3.1 169 CE-46 A3a DHBP 0.29 13 188 2.3 > 100 CE-47 A3a DHBP 0.30 13 188 2.2 > 200 CE-48 A3a DHBP 0.50 13.5 186 1.9 > 200 CE-49 A3a DHBP 0.57 12 186 1.9 > 100 CE-50 A3a TBEH 0.30 17 197 8.8 12.0 CE-51 A3a TBEH 0.67 14 188 7.2 24.4 CE-52 A3a TBEH 0.98 14 189 6.8 25.6 CE-53 A3a TBPB 0.31 13 186 2.6 95 CE-54 A3a TBPB 0.64 13 184 2.1 238 CE-55 A3a TBPB 1.03 12 184 1.9 > 250 CE-56 A3a DCP 0.08 16 192 3.8 47.1 CE-57 A3a DCP 0.17 14 189 2.9 121.3 CE-58 A3a DLP 0.32 16 191 10.9 14.5 CE-59 A3a DLP 0.64 16 190 10.6 17.9 CE-60 A3a DLP 0.95 16 189 10.4 16.6 Examples 78 to 82 LYM120 was modified according to Table 14 below. LYM120 is a low molecular weight / MFI injection molding grade polypropylene copolymer.

Table 14: Example Conditions Starter Initiator (% Current MFl Time Temp 2.16 kg weight) of given motor (° C) drop (s) @ 230 ° C (amp) Control A3a BPO 0 16 195 9.9 12.8 24 78 A3a BPO 0.25 15 196 10.3 13.4 79 A3a BPO 0.47 14 198 13.2 13.1 80 A3a BPO 0.64 16 198 13.9 12.9 81 A3a BPO 0.70 17 201 13.6 11.9 82 A3a BPO 0.94 18 198 13.5 10.6 CE-61 A3a DHBP 0.09 14 190 3.6 80 CE-62 A3a DHBP 0.16 13 188 3.1 160 CE-63 A3a DHBP 0.26 13 187 2.8 250 CE-64 A3a TBEH 0.29 15 193 7 CE-65 A3a TBEH 0.60 13 192 6.7 19.4 CE-66 A3a TBEH 1.02 12 191 6 22.6 CE-67 A3a TBPB 0.30 13 186 3.6 85"CE-68 A3a TBPB 0.61 12 184 3.8 173 CE-69 A3a TBPB 0.92 12 184 3.4> 250 CE-70 A3a DCP 0.08 16 192 4.5 14.6 CE-71 A3a DCP 0.17 13 190 3 107 CE-72 A3a DCP 0.25 13 188 3 131 CE-73 A3a DLP 0.32 14.5 191 9.5 14.3 CE-74 A3a DLP 0.68 15 191 9.4 15.8 CE-75 A3a DLP 0.98 14.5 193 8.7 21.0 Examples 83 to 92 LYMV120 was modified in accordance with Table 15 below. LYM120 is a low molecular weight / MFI injection molding grade polypropylene copolymer.

Table 15: Example Condicio Initiator Starter Styrene Ropoiobn Current Temp. Time MFl 2.16 Strengths (% in (% in meter of drop die motor kg @ melting weight) weight) (Estini) (amp) (° C) (s) 230 ° C (cN) CE-76 A3a 0 0 0 16 195 9.9 12.8 1.1 83 A3a BPO 0.43 0.19 1.04 16 207 18.5 6.9 84 A3a BPO 0.41 0.37 2.07 19 207 22.5 4.9 85 A3a BPO 0.41 0.55 3.11 20 208 25.8 4.4 11.6 86 A3a BPO 0.43 0.76 4.14 21 210 25.4 3.9 87 A3a BPO 0.45 0.99 5.18 20 205 28.3 4.4 88 'A3a TBPB 0.56 0.19 0.78 13 192 8.9 71 89 A3a TBPB 0.55 0.37 1.57 14 196 11.0 38 90 A3a TBPB 0.61 0.62 1.91 17 200 14.6 33 91 A3a TBPB 0.54 0.73 3.14 16 201 16.0 19.2 92 A3a TBPB 0.58 0.97 3.92 19 204 16.2 15.7 CE-77 A3a DHBP 0.27 0.1 0.084 13 190 4.4 187 CE-78 A3a DHBP 0.25 0.18 1.69 14 191 5.3 125 CE-79 A3a DHBP 0.28 0.30 3.04 14.5 190 5.6 114 CE-80 A3a DHPB 0.27 0.40 3.38 15 193 6.2 116 CE-81 A3a DHBP 0.28 0.50 4.22 14 192 6.1 118 Examples 93 to 97 GYM45 was modified according to Table 16 below. GYM45 is a low molecular weight / MFI injection molding grade polypropylene homopolymer.

Table 16: Example CondicioIniciador Iniciador Estíreno Proportion Current Temp. of Time of MFl 2.16 nes (% in (% in molar of given motor (° C) drop (s) kg @ weight) weight) est / ini (amp) 230 ° C CE-32 A3d - 0.00 0.00 0.00 18 192 11.8 12.75 93 A3d BPO 0.36 0.16 1.07 18 202 18.1 11.17 94 A3d BPO 0.41 0.37 2.07 18 209 23.5 6.38 95 A3d BPO 0.41 0.55 3.11 20 206 27.6 5.62 96 A3d BPO 0.43 0.76 4.14 22 209 25.7 4.05 97 A3d BPO 0.40 0.89 5.18 21 207 31.2 4.27 Examples 98 to 105 LYM120 was modified in accordance with Table 17 below. LYM120 is a low molecular weight / MFI injection molding grade polypropylene copolymer. 77 # Table 17: Example Condition - Initiator # 1 Initiator # 2 Proportion Monomer Proportion Current Temp Temp. MFl Strengths% in weight% in molar weight% in molar weight of engine drop (s) given ° C fusion (cN) ini # 1 / ini # 2 monomer / (amp) t tot Initiator # 1 = PBO, Initiator # 2 = DHBP, Monomer = styrene 98 A3d 0.43 0.06 9.08 0.57 2.81 19 17 204 6.9 3.8 99 A3d 0.43 0.11 4.54 0.58 2.57 19 14.8 203 10.5- 2.9 100 A3d 0.43 0.17 3.03 0.58 2.37 18 14 201 16.9 _ ii- »i > -, iin? iuuu t-f, ivi? uui IICI \ J - ou icu? oo 101 A3d 0.43 0.11 3.07 0.58 2.36 20 18.7 208 5 5.5 102 A3d 0.43 0.22 1.53 0.58 1.92 17 14.2 204 9.3 4.2 103 A3d 0.43 0.34 1.02 0.59 1.62 18 14 204 11.6 - 104 A3d 0.43 0.45 0.77 0.60 1.40 18 11.8 201 19.5 - 105 A3d 0.43 0.34 1.02 0.94 2.59 21 17 207 7.5 6.3 Examples 108 and 109 Montell 6501 was modified according to Table 19 below in the Killion screw extruder described above.

• Sample Temp. Output of BPO% in Styrene Current Time of MFl (g / 10 barrel (° C) extruder Weight% in weight of given motor (° C) drop (s) min) (kg / h) (amp) Control - - - - - - - 4.1 CE 84 220 1.4 256 17 4.1 fixed 108 220 1.4 2.1 0.25 6 260 35 2.2 fixed 109 220 1.4 4.2 0.5 7.5 263 33 0.40 fixed Examples 40.41.7.12.28.29.31 and 14 The GPC molecular weights were determined using a Waters 150C high temperature GPC unit. 1, 2,4-trichlorobenzene was used • as the solvent, levigating through two linear columns Ultrastyragel. The oven temperature was set at 140 ° C and the flow rate of the pump was 1.0 ml / min. The calibration was performed using narrow polydispersity polystyrene standards. All molecular weights were cited as polystyrene equivalents. 15 Mn = number average molecular weight Mw = weight average molecular weight Mz = viscosity average molecular weight Mp = peak molecular weight Errors are cited as twice the standard deviation between duplicates of injections.

Table 20: Example Cond. BPO (% Esti (% in MFl (g / 10 Fza of Mn Mw Mz (g / mol) Mp not by weight) weight) m? N) fusion (g / mol) x (g / mol) xx 10'3 (g / mol) x (cN) 10'3 10'3 Homopol PP number of intermediate molecular weight (GWM 22) Control 4.5 2.8 55 295 1 200 1 05 4 8 B1a 1.0 5.0 6.9 80 425 1415 200 B1a 0.12 0.16 4.15 90 405 1200 235 11 B1a 0.23 0.31 2.80 5.0 75 415 1400 195 12 B1a 0.46 0.61 1.11 70 555 2200 205 13 B1a 0.69 0.92 0.69 1 8.6 85 575 2200 180 110 C2a 1.50 3.8 75 430 1560 160 111 C2a 2.23 3.2 75 430 1700 150 112 C1a 0.37 0.49 2.22 85 565 2035 215 113 C1a 0.60 0.80 1.00 1 9.4 85 690 2575 170 114 C1a 0.32 1.65 4.50 80 505 1835 170 1 15 C 1 to 0.47 2.45 1 .58 - 90 605 2160 205 1 16 C 1 to 0.81 4.19 0.69 1 8.8 85 675 261 0 185 Low molecular weight PP copolymer (PXCA 61 52) Control - - - 12.4 1.4 45 230 720 130 5 22 B1a 1.04 0.65 17.7 110 485 1615 195 27 A2a 0.33 0.44 - 7.4 65 325 1045 140 61 A2a 0.41 0.55 4.4 11.5 60 325 1315 125 62 A2a 0.62 0.83 2.9 - 70 460 2435 135 - D2a 0.28 0.38 - - 80 555 2875 160 28 D2a 0.32 0.44 - 9.0 120 640 4130 140 78 A3a 0.25 13.4 - 70 315 1330 135 79 A3a 0.47 13.1 - 65 320 1380 130 80 A3a 0.64 12.9 - 65 360 1975 130 27 D3a 0.68 13.1 2.3 70 445 1865 140 * Errors in molecular weight are generally less than 30% of the quoted value, as is usual in high temperature GPC under the conditions used.

Examples 1 10 to 1 14 GWM22 and KM61 00 were modified in accordance with Table 20 below.

Table 20: Effect of addition of BPO feed throat in the modification of pre-stabilized PP homopolymer [KM6100 or GWM22] to Example Condicio- Powder% BPO (% Current Temp Temp of MFl (g / 10 Fza. weight in weight) of given motor (s) (° C) min) fusion to (amp) (cN) Homopol pre-stabilized PP number GWM 22 Control 2.8 4 1 10 J3d 8.8 0.92 25 18 244 3.9 1 1 .0 1 1 1 J3d 13.3 1 .40 30 19 248 2.6 8.5 Homopolymer of pre-stabilized PP KM6100 Control -3.5 2.5 CE-85 J3d 0 0 27 11 240 3.7 2.5 112 J3d 2.0 0.41 26 15 235 4.9 39 113 J3d 3.9 0.81 27 19 241 3.3 6.7 114 J3d 6.2 1.28 28 19 241 2.7 9.5 a: BPO added to PP powder pellet feed derived from pre-stabilized PP pellets, criomolides Examples 1 15 to 1 17 KMT61 00 was modified in accordance with Table 22 below. KMT6100 is a pre-stabilized PP polymer copolymer.

Table 22: Effect of addition of BPO feed throat in the modification of pre-stabilized PP copolymer [KMT61 00] Example Powder% BPO (% Current Temp of MFl (g / 10 Frs. weight) of the given drop motor (s) (° C) min) fusion to (amp) (cN) Control -3.5 2.0 or CE-86 J3d 0 0 24 8 231 4.4 2.0 1 1 5 J3d 1 .9 0.40 25 10 233 5.4 1 .9 1 16 J3d 3.0 0.81 24 1 3 235 4.4 3.1 1 17 J3d 5.9 1 .22 29 15 237 3.0 4.5 a: BPO added to feed PP pellets derived from pre-stabilized PP pellets, criomolides Examples 1 18 to 121 KM6100u was modified with para-toluoyl peroxide (PTP) and BPO according to Table 23 below. The KM6100u was stabilized with I rganox 101 0 (0.33% by weight) and I rgaphos 168 (0.17% by weight), which were added to the main feed throat of the extruder.

Table 23 Example Powder Condition% BPO (% Current MFl Temp Time (g / 10 Fs. Of weight-based weight) of given motor (s) (° C) min) fusion to (amp) (cN) Control -3.5 -2.5 g CE-86 J3d - 0 22 9 240 5.2 2.7 1 18 J3d BPO 1 .0 22 17 252 5.2 7.2 1 19 J3d PTP 1 .0 21 16 240 5.2 6.8 120 J3d PTP 1 .5 22 18 239 3.9 14.2 121 J3d PTP 2.0 24 243 3.4 14.0 Examples 122 to 128 PXCA6152 was modified with mixed primer systems according to Table 24 below: Table 24: Example Condicio Ini # 1% iní # 2% Proportional Current Temp. Mfl Weight of weight in weight per mole of die-drop motor (g / 10 fusion or # 1 / ini # 2 (amp) (s) ° C min) (cN) Control 5 0.8 6 CE-88 B3a 0 0 - 22 14 255 0.9 5.1 122 B3a 0.87 0 - 24 20 257 1 .28 14.2 Initiator # 1 = BPO, Initiator # 2 = DHBP 123 B3a 0.87 0.045 23.2 22 1 9 251 4.0 8.0 124 B3a 0.87 0.064 16.3 20 1 6 250 5.4 125 B3a 0.87 0.084 1 2.4 20 15 248 6.4 0.2 Initiator # 1 = BPO, Initiator # 2 = TBPB 126 B3a 0.87 0.006 129.4 22 16 254 3.4 127 B3a 0.87 0.01 2 64.7 20 16 249 3.9 0.5 128 B3a 0.87 0.019 40.9 20 16 249 6.4 0.1 Examples 129 to 132 PXCA61 52 Criomolide in the form of a powder was modified with mixed primer systems according to Table 25 below.

Table 25: Effect of mixed primers on powder modification of PXCA61 52 a (criomolide pellets) Example Condício Ini # 1% Ini # 2% Proportion Current Temp. Mfl Weight of weight in weight molar molar of die drop motor (g / 10 fusion ini # 1 / ini # 2 (amp) (s) ° C min) (cN) Control 5? 7d (3 CE-89 B3d 0 0 - 25 13 256 1 .0 Initiator # 1 = BPO, Initiator # 2 = DHBP 129 B3a 0.86 0 - 23 17 253 1 .8 10.8 130 B3a 0.87 0.004 23 17 254 2.1 8.8 Initiator # 1 = BPO, I niciador # 2 = TBPB 131 B3a 0.87 0.016 24 253 2.6 8.2 132 B3a 0.87 0.026 23 17 253 3.6 7.7 • Examples 79 and 85 LYM120 was modified in accordance with Table 26 below.

Table 26: Example Conditional BPO% Mono- Current Monomer Temp. MFl F ers of weight in mere weight / co% by weight of motor of drop of die (g / 0 fusion - agent (amp) (s) ° C min) (cN) Control 6 12.2 1.4 CE-76 Aa 0 None 0 16 10 195 12.8 1.1 79 Aa 0.47 None 0 14 13 198 13.2 85 Aa 0.41 Styrene 0.54 20 25.8 208 4.4 11.6 Example 133 GYM22 was modified in accordance with Table 27 below. Table 27: Example Conditional BPO% Monó- Monómero Current Temp Temp. MFl Weight of nero weight / co% by weight of die-drop motor (g / 10 melt-to-agent (amp) (s) ° C min) (cN) Control 4 4.5 2.8 CE-2 B1a 0 None - 16 11 239 5 - 6 B1a 0.36 None - 16 15 234 6.3 3 133 B1a 0.34 Styrene 0.45 21 29 250 1.72 - Examples 1 34 to 1 37 KM6100 Criomolide in the form of a powder was modified in a single screw extruder Brabender according to the general description of SSE Brabender above and Table 28 below. The initiator was added to the SSE feed throat together with the stabilizers (0.33% by weight of Irganox 1010 and 0.17% by weight of Igagaphos 168).

Table 28: Example Type of Peroxide Peroxide (% by weight) MF (g / 10 min) Control 8 - 0 3.5 134 BPO 1 2.9 135 PTP 0.5 3.8 1 36 PTP 1 3.3 137 PTP 2 2.0 PTP - paratoluol peroxide (bis paramethyl benzoyl peroxide) Example 138 PXCA6152 was modified in accordance with Table 29 below.

Table 29: Modification of pellets of PXCA6152 Example Conditions BPO (% Styrene Current Time Temp. MFl 2.16 Weight force) (% in given motor (° C) drop (s) kg @ fusion weight) (amp) 230 ° C (cN) Control 0.8 6.0 3 CE 4 B3a 0 - 22 14 255 0.9 5.1 138 B3a 0.51 0.68 24 19 279 0.6 21 .0 Examples 139 to 143 The modified PXCA6152 produced according to Example 1 38 was melt blended with GYM45 according to Table 30.

Table 30: Mixtures of the modified PP with other PP homopolymers Example CondiPP # 1 (% in PP # 1 (% by weight) Current Time Temp. MFl Strengths weight) of the drop motor of the (amp) (s) ° C melting CE-95 A3 Control 5 (5) Control 3 (95) 18 1 1 206 9.9 CE-96 A3 Control 5 (10) Control 3 (90) 1 9 1 2 202 7.8 CE-97 A3 Control 5 (15) Control 3 (95) 1 9 1 3 202 7.0 CE-98 A3 Control 5 (20) Control 3 (80) 19 14 202 5.5 CE-99 A3 Control 5 (25) Control 3 (75) 19 15 202 4.7 2.6 139 A3 138 (5) Control 3 (95) 19 1 5 199 9.3 140 A3 138 (10) Control 3 (90) 1 9 16 201 7.4 141 A3 138 (15) Control 3 (85) 19 18 203 6.6 142 A3 138 (20) Control 3 (80) 20 1 9 204 5.0 143 A3 138 (25) Control 3 (75) 1 9 20 207 4.7 5.2 CE- A3 - Control 4 (100) 20 15 208 5.3 100 144 A3 138 (5) Control 4 (95) 21 18 207 3.7 145 A3 138 (10) Control 4 (90) 21 19 206 3.5 146 A3 138 (15) Control 4 (85) 22 21 210 2.3 147 A3 138 (20) Control 4 (80) 22 21 212 2.6 148 A3 138 (25) Control 4 (75) 23 23 213 2.4 77 Examples of modified carbon dioxide foaming of modified PP The equipment used to foam the polypropylene (from previous examples) was a tandem extrusion line made of a Leitritz twin screw extruder (screw diameter of 34 mm, co-rotating, with 1 1 sections of barrel), connected via a fusion pipe to a single screw extruder (screw diameter of 43 mm). CO2 was introduced into barrel six of the twin screw extruder. The gasified polymer was then cooled slowly in the single screw extruder.

Example MFl (g / 1 0 Density Temp. Strength min. Size) fusion (cN) foamed foam cell (° C) average average (g / cc) (μm) Control 1 31 18 166 to 1 59 0.058 550 0.4 169 to 159 0.044 300 31 6.5 1 1 .2 167 to 161 0.051 280 Degrees of non-high melting strength of polypropylene have foam temperature processing windows of less than 1 ° C. Both foamed examples 13 and 17 have a thin closed cell structure.

Examples of thermoforming The modified polypropylene produced in Example 69 was extruded in a Welex single screw extruder through a die of sheet to produce a sheet 78 cm wide and 1.25 mm thick. The sheet was fed to a Gabler F702 continuous thermoformer to produce margarine tubes. The tubes produced from the modified PP sample had a pressure strength of 25 kg after 1 hour. No appreciable buckling of the PP sheet was noticed during the process.

Blow molding The modified polypropylene of Example 5 was blow molded into a Bekum blow molder fitted with a general purpose polyolefin screw using a 750 ml top screw bottle mold (a radially non-symmetrical bottle with waist). The temperature of the mold was 0 ° C. The ability to blow molding the modified injection molding grade PP was compared to that of a commercial low flow PP PP homopolymer (ICI GWM 11.0 of MF1 = 1.5).

» It was found that the modified PP homopolymer (MFl = 9.1 and melting strength = 6.9 cN) could be easily blow molded into 750 ml bottles. Conventional PP of similar MFl could not be blow molded successfully. The modified PP gave a similar performance to a PP of low MFl extrusion grade. The results are very promising where a higher MFl PP could be used to blow bottles. This possibly opens up the opportunity to produce blow molded parts through the use of a modified PP of high melting strength, which has been adapted to have a MFl acceptable for blow molding (ie 1 -2 MFl). Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications different from those specifically described. It will be understood that the invention includes all those variations and modifications that fall within its spirit and scope. The invention also includes all steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of two or more of said steps or features. twenty

Claims (19)

1. « REIVI NDICATIONS 1 . A process for increasing the melting strength and / or the melting viscosity of a polypropylene (co) polymer, wherein said process comprises melt blending the polypropylene (co) polymer in the presence of an initiator, wherein said initiator is selected from the group defined by formula 1. 10 Formula 1 wherein R is selected from the group consisting of optionally substituted acyl of d to C18, optionally substituted C1 to C18 alkyl, aroyl defined by formula 2, • Formula 2 and groups of formula 3, Formula 3 • where U, V, X, Y, Z, U ', V, X', Y 'and Z' are selected 10 independently of the group consisting of hydrogen, halogen, C 1 -C 8 alkyl, C 1 -C 8 alkoxy, aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, aryloxycarbonyl, trialkyl silyl, hydroxy, or a portion of formula 4, fifteen Formula 4 and where T is alkylene.
2. 2. A process according to claim 1, wherein the initiator is selected from compounds of formula 6, Formula 6 where X, Y, Z, U, V, X ', Y', Z ', U', V are independently selected from the group consisting of hydrogen and Ci-C18 alkyl, where at least one of X, Y, Z , U, V and X ', Y', Z ', U', V is not hydrogen.
3. 3. A process according to claim 2, wherein the initiator is selected from the group consisting of dibenzoyl peroxide, o-peroxide, o'-bis (methylbenzoyl), p-peroxide, p'-bis (methylbenzoyl! ), M peroxide, M'-bis (methylbenzoyl), o-peroxide, m'-bis (methylbenzoyl), o-peroxide, p'-bis (methylbenzoyl), m-peroxide, p'-bis (methylbenzoyl), bis (ethylbenzoyl) peroxide (all isomers), bis (propylbenzoyl) peroxide (all isomers), bis (butylbenzoyl) peroxide (all isomers), bis (pentylbenzoyl) peroxide (all isomers), peroxide bis (hexylbenzoyl) (all isomers), bis (heptylbenzoyl) peroxide (all isomers), bis (octylbenzoyl) peroxide (all isomers), bis (nonylbenzoyl) peroxide (all isomers), bis peroxide ( methoxybenzoyl) (all isomers), bis (ethoxybenzoyl) peroxide (all isomers), bis (propoxybenzoyl) peroxide (all isomers), hydrogen peroxide, is (butoxybenzoyl) (all isomers), bis (pentoxybenzoyl) peroxide (all isomers), bis (hexyloxybenzoyl) peroxide (all isomers), bis (heptyloxybenzoyl) peroxide (all isomers), bis peroxide ( octyloxybenzoyl) (all isomers), bis (noniloxibenzoyl) peroxide (all isomers), bis (chlorobenzoyl) peroxide (all isomers), bis (fluorobenzoyl) peroxide (all isomers), bis (bromobenzoiio) peroxide (all isomers), bis (dimethylbenzoyl) peroxide (all isomers), bis (trimethylbenzoyl) peroxide (all isomers), bis (tert-butylbenzoyl) peroxide (all isomers), bis (di-) peroxide tert-butylbenzoyl) (all isomers), bis (tert-butoxybenzoyl) peroxide (all isomers), bis (ditrimethylsilylbenzoyl) peroxide (all isomers), bis (heptafluoropropylbenzoyl) peroxide (all isomers), bis peroxide ( 2,6-dimethyl-4-trimethylsilyl benzoyl) and isomers, dibut the ester of 2,2 '(dioxydicarbonyl) bis-benzoic acid, where the term "all isomers" refers to any variation in the position of the ring substituent, as well as the structure of the substituent by itself, i.e. , for propyl; n-propyl and isopropyl.
4. 4. A process according to claim 1, wherein the initiator is selected from the group consisting of tert-butyl perbenzoate, tert-butyl (metii) perbenzoate (all isomers), tert-butyl (ethyl) perbenzoate (all isomers), tert-butyl (octyl) perbenzoate (all isomers), tert-butyl (nonyl) perbenzoate (all isomers), ter-amyl perbenzoate, ter-amyl (methyl) perbenzoate (all isomers), ter-amyl (ethyl) perbenzoate (all isomers, » (octyl) ter-amyl perbenzoate (all isomers), tert-amyl (nonyl) perbenzoate (all isomers), tert-amyl (methoxy) perbenzoate (all isomers), ter-amyl (octyloxy) perbenzoate (all isomers), (nonyloxy) perbenzoate of ter-amino (all isomers), perbenzoate of • 5-2-ethylhexyl, 2-ethylhexyl (methyl) perbenzoate (all isomers), 2-ethylhexyl (ethyl) perbenzoate (all isomers), 2-ethylhexyl (octyl) perbenzoate (all isomers), (nonyl) ) 2-ethylhexyl perbenzoate (all isomers), 2-ethylhexyl (methoxy) perbenzoate (all isomers), 2-ethylhexyl (ethoxy) perbenzoate (all isomers), 2-Ethylhexyl 10 (octyloxy) perbenzoate (all isomers, • (2-ethylhexyl) (nonyloxy) perbenzoate (all isomers).
5. 5. A process according to claim 1, wherein the initiator is selected from the group consisting of bis (tert-butyl monoperoxy phthaloyl) diperoxy terephthalate, diperoxy terephthalate 15 bis (tertamilmoperoxy phthaloyl), diacetyl phthaloyl dioperoxide, dibenzoyl phthaloyl dioperoxide, bis (4-methylbenzoyl) phthaloyl-diperoxide, diacetyl-terephthaloyl-diperoxide, dibenzoyl-terephthaloyl-diperoxide, poly-dioxycarboniidioxy peroxide (1, 4, 4- tetramethyl-1,4-butanediyl)].
6. 6. A process according to claim 1, wherein the initiator 20 has 0.1 hour half-life in the range of 100-170 ° C.
7. 7. A process according to claim 1, wherein the initiator is present in the range from 0.004 to 0.25 moles of initiator per kg of the homopolymer or polypropylene copolymer.
8. 8. A process according to claim 1, wherein the initiator is present in the range from 0.006 to 0.10 moles of initiator per kg of the polypropylene homopolymer or copolymer.
9. 9. A process according to claim 1, wherein the initiator is present in the range from 0.01 to 0.05 moles of initiator per kg of the homopolymer or polypropylene copolymer.
10. 10. A process according to claim 1, wherein there is no added monomer and the initiator is selected from the group consisting of dibenzoyl peroxide, o-o-o-bis (methylbenzoyl) peroxide, p-peroxide, p ' -bis (methylbenzoyl), o-peroxide, o'-bis (methiibenzoyl), o-peroxide, m'-bis (methylbenzoyl), o-peroxide, p'-bis (methylbenzoyl), peroxide m, p'-b S (methylbenzoyl), bis (ethylbenzoyl) peroxide (all isomers), bis (propylbenzoyl) peroxide (all isomers), bis (butylbenzoyl) peroxide (all isomers), bis (pentylbenzoyl) peroxide (all isomers), bis (hexylbenzoyl) peroxide (all isomers), bis (heptylbenzoyl) peroxide (all isomers), bis (octylbenzoyl) peroxide (all isomers), bis (nonylbenzoyl) peroxide (all isomers) ), bis (methoxybenzoyl) peroxide (all isomers), bis (ethoxybenzoyl) peroxide (all isomers), bis (propoxybenzoyl) peroxide ) (all isomers), bis (butoxybenzoyl) peroxide (all isomers), bis (pentoxybenzoyl) peroxide (all isomers), bis (hexyloxybenzoyl) peroxide (all isomers), bis (heptyloxybenzoyl) peroxide ( all isomers), bis (octyloxybenzoyl) peroxide (all isomers), bis (noniloxibenzoyl) peroxide (all isomers), bis (chlorobenzoyl) peroxide (all isomers), - bis (fluorobenzoyl) peroxide (all isomers), bis (bromobenzoyl) peroxide (all isomers), bis (dimethylbenzoyl) peroxide (all isomers), bis (trimethylbenzoyl) peroxide (all isomers), bis (tert-butylbenzoyl) peroxide (all isomers), peroxide 5 of bis (di-tert-butylbenzoyl) (all isomers), bis (tert-butoxybenzoyl) peroxide (all isomers), bis (ditrimethylsilylbenzoyl) peroxide (all isomers), bis (heptafluoropropylbenzoyl) peroxide (all isomers) ), bis (2,4-dimethyl-6-trimethylsilyl benzoyl) peroxide and ter-amyl perbenzoate isomers, 10 (methyl) perbenzoate of ter-amyl (all isomers), (nonyl) perbenzoate of ter-amino (all isomers), (methoxy) perbenzoate of ter-amyl (all isomers), (octyloxy) perbenzoate of ter- amyl (all isomers), tert-amyl (nonyloxy) perbenzoate (all isomers), bis (teramylmonoperoxy phthaloyl) d-perosi terephthalate, diacetii phthaloyl dioperoxide, Dibenzoyl phthaloyl diperoxide, bis (4-methylbenzoyl) phthaloyl dioperoxide, diacetyl terephthaloyl diperoxide and dibenzoyl terephthaloyl dioperoxide. eleven .
11. A process according to claim 10, wherein the initiator is more preferably selected from the group consisting of dibenzoyl peroxide, o-peroxide, o'-bis (methylbenzoiio), p-peroxide, p'-20 bis (methylbenzoyl) ), M peroxide, M'-bis (methylbenzoyl), o-peroxide, m'-bis (methylbenzoyl), o-peroxide, p'-bis (methylbenzoyl), m-peroxide, p'-bis (methylbenzoyl).
12. 12. A process according to claim 1, wherein the initiator is used in combination with a monomer.
13. 13. A process according to claim 12, wherein the amount of monomer is up to 5 times the total moles of the initiator.
14. 14. A process according to claim 12 or claim 13, wherein the monomer is a monoene monomer.
15. 15. A process according to claim 1 2 or claim 13, wherein the monomer is styrene.
16. 16. A process according to claim 1, wherein the initiator is selected from the group consisting of dibenzoyl peroxide, o-peroxide, o'-bis (methylbenzoyl), p-peroxide, p'-bis (methylbenzoyl) , M peroxide, M'-bis (methylbenzoyl), o-peroxide, m'-bis (methylbenzoyl), o-peroxide, p'-bis (methyl benzoyl), m-peroxide, p'-bis (methylbenzoyl) , bis (ethylbenzoyl) peroxide (all isomers), bis (propylbenzoyl) peroxide (all isomers), bis (butylbenzoyl) peroxide (all isomers), bis (pentylbenzoyl) peroxide (all isomers), peroxide of bis (hexylbenzoyl) (all isomers), bis (heptylbenzoyl) peroxide (all isomers), bis (octylbenzoyl) peroxide (all isomers), bis (nonylbenzoyl) peroxide (all isomers), bis peroxide (methoxybenzoyl) (all isomers), bis (ethoxybenzoyl) peroxide (all isomers), bis (propoxybenzoyl) peroxide (all isomers), peroxide or of bis (butoxybenzoyl) (all isomers), bis (pentoxybenzoyl) peroxide (all isomers), bis (hexyloxybenzoyl) peroxide (all isomers), bis (heptyloxybenzoiio) peroxide (all isomers), peroxide bis (octyloxybenzoyl) (all isomers), bis (noniloxibenzoyl) peroxide (all isomers), bis (chlorobenzoyl) peroxide (all isomers), j, bis (fluorobenzoyl) peroxide (all isomers), bis (bromobenzoyl) peroxide (all isomers), bis (dimethylbenzoyl) peroxide (all isomers), bis (trimethylbenzoyl) peroxide (all isomers), peroxide bis (tert-butylbenzoyl) (all isomers), peroxide • 5-bis (di-tert-butylbenzoyl) (all isomers), bis (tert-butoxybenzoyl) peroxide (all isomers), bis (ditrimethylsilylbenzoyl) peroxide (all isomers), bis (heptafluoropropylbenzoyl) peroxide (all isomers), bis (2,4-dimethyl-6-trimethylsilyl benzoyl) peroxide and isomers, acid dibutyl ester 10 2,2 '(dioxydicarbonyl) bis-benzoic acid, tert-butyl perbenzoate, (methyl) tert-butyl perbenzoate (all isomers), tert-butyl (ethyl) perbenzoate (all isomers), tert-butyl (octyl) perbenzoal (all isomers), tert-butyl (nonyl) perbenzoate) (all isomers), ter-amyl perbenzoate, ter-amyl (methyl) perbenzoate (all 15 isomers), ter-amyl (ethyl) perbenzoate (all isomers, tert-amyl (octyl) perbenzoate (all isomers), tert-amyl (nonyl) isomer (all isomers), (methoxy) perbenzoate) ter-amyl (all isomers), ter-amyl (octyloxy) perbenzoate (all isomers), (nonyloxy) ter-amino perbenzoate (all isomers), perbenzoate 20 2-ethylhexyl, 2-ethylhexyl (methyl) perbenzoate (all isomers), 2-ethylhexyl (ethyl) perbenzoate (all isomers), 2-ethylhexyl (octyl) perbenzoate (all isomers), (nonyl) 2-ethylhexyl perbenzoate (all isomers), 2-ethylhexyl (methoxy) perbenzoate (all isomers), 2-ethylhexyl (ethoxy) perbenzoate (all isomers), 2-Ethylhexyl 2-octyloxy) perbenzoate (all isomers, • «< (nonyloxy) 2-ethylhexyl perbenzoate (all isomers), diperoxy terephthalate of bis (tert-butyl monoperoxy phthaloyl), diperoxy terephthalate of bis (teramylomonoperoxy phthaloyl), diacetyl phthaloyl dioperoxide, dibenzoyl phthaloyl dioperoxide, bis (4-methylbenzoyl) dioperoxide ) phthaloyl, diacetyl terephthaloyl peroxide, dibenzoyl terephthaloyl dioperoxide, poly [dioxycarbonyldioxy (1, 1, 4, 4-tetramethyl-1,4-buta nodule)] peroxide].
17. 17. A modified polypropylene produced according to one of the processes of claims 1, 10 and 12.
18. 1 8. A process, wherein the modified polypropylene of the 10 claim 1 7 is mixed with fusion with an unmodified polypropylene Or to produce a modified polypropylene.
19. 19. A process for modifying an α-olefin polymer, wherein said process comprises melt-blending the α-olefin polymer in the presence of an initiator, and optionally a monoene monomer, in Wherein said initiator is selected from the group defined by formula 1, Formula 1 wherein R is selected from the group consisting of optionally substituted C, optionally substituted C18 alkyl, optionally substituted Ci to C18 alkyl, aroyl defined by formula 2, Or Formula 2 and groups of formula 3, 10 Formula 3 Wherein U, V, X, Y, Z, U ', V, X', Y 'and are independently selected from the group consisting of hydrogen, halogen, C 1 -C 8 alkyl, C 1 -C 1 alkoxy , aryloxy, acyl, acyloxy, aryl, carboxy, alkoxycarbonyl, aryloxycarbonyl, trialkylsilyl, hydroxy, or a portion of formula 4, Formula 4 and wherein T is alkylene; and wherein the amount of monomer is 0 to 5 times the total moles of initiator.