Disclosure of Invention
The present invention aims to provide a polypropylene composition and a method for preparing the same, which aims to overcome the defects of the prior art. The polypropylene composition provided by the invention has good toughness, flexural modulus and adhesive property.
The polypropylene composition comprises, by weight, 55-90 parts of polypropylene resin, 1-5 parts of hyperbranched polymer, 5-10 parts of toughening agent, 5-10 parts of compatilizer, 0-30 parts of modified montmorillonite and 0.5-1 part of antioxidant.
The hyperbranched polymer is a star-shaped or dendritic polymer, contains a large amount of active groups and has good bonding performance, and the polypropylene composition can improve the bonding performance of materials on one hand, can be directly bonded with metals in molding without additionally adding a layer of tackifier materials, can simplify the process and save the cost, and can improve the compatibility of montmorillonite and matrix resin and improve the toughness and rigidity of the materials on the other hand. In addition, as the hyperbranched polymer content increases, the toughness and peel strength of the material increases.
As a preferred embodiment of the present invention, the hyperbranched polymer is at least one of hyperbranched polyethyleneimine, hyperbranched polyester, hyperbranched unsaturated resin, and hyperbranched epoxy resin.
The hyperbranched polymer contains more polar functional groups such as amino groups, amide groups, ester groups, unsaturated groups or epoxy groups on the molecular chain, has better compatibility with resin and filler, and improves the performance of the whole material such as mechanical performance, processability, adhesiveness and the like.
As a preferred embodiment of the invention, the hyperbranched polymer has a degree of branching of from 0.5 to 0.7.
The degree of branching of the hyperbranched polymer influences the mechanical properties and the adhesive properties of the polypropylene composition. With increasing branching of the hyperbranched polymer, the impact strength and the adhesive properties of the polypropylene composition are enhanced and the flexural modulus is slightly reduced. However, the branching degree of the hyperbranched polymer is too high, the compatibility of the hyperbranched polymer and polypropylene is poor, and the mechanical property and the adhesive property of the material are reduced.
As a preferred embodiment of the invention, the modified montmorillonite is montmorillonite with the surface being modified by acidification and/or modified by quaternary ammonium salt, the D50 particle size of the modified montmorillonite is 2-5 mu m, and more preferably, the modified montmorillonite is montmorillonite with the surface being modified by acidification and modified by quaternary ammonium salt.
The montmorillonite is a lamellar silicate with stronger polarity, and after radial acid treatment, the polar bond is passivated, the specific surface area is increased, the aperture is increased, and meanwhile, after quaternary ammonium salt treatment, the adsorption property and the bonding performance of the montmorillonite are enhanced, and the compatibility with resin can be improved. Compared with unmodified montmorillonite, the mechanical property and the bonding property with metal of the polypropylene composition prepared by the modified montmorillonite are obviously enhanced.
As a preferred embodiment of the present invention, the polypropylene resin has a melt flow rate of 1 to 5g/10min under test conditions of 230℃and 2.16kg according to test standard ISO 1133-1-2011.
The invention selects the polypropylene resin with low melt flow rate, which is beneficial to material extrusion molding, and can avoid unstable molding due to low viscosity and high melt flow property of polypropylene.
As a preferred embodiment of the invention, the toughening agent is at least one of POE, EVA, an acrylic elastomer and EPDM, and the melt flow rate of the toughening agent is 0.5-5g/10min under the test condition of 190 ℃ and 2.16kg according to the test standard ISO 1133-1-2011.
As a preferred embodiment of the invention, the compatibilizer is polypropylene grafted maleic anhydride.
According to the invention, the antioxidant is a mixture of the antioxidant 1010 and the antioxidant 168, and the mass ratio of the antioxidant 1010 to the antioxidant 168 is 1 (1-2).
In addition, the invention also claims a preparation method of the polypropylene composition, which comprises the following steps:
(1) Uniformly mixing a hyperbranched polymer, modified montmorillonite and a compatilizer, and then carrying out melt extrusion granulation to obtain a mixture;
(2) And mixing the mixture, the polypropylene resin, the toughening agent and the antioxidant, and carrying out melt extrusion and granulation to obtain the polypropylene composition.
As a preferred embodiment of the invention, in the step (2), the device for melt extrusion and granulation is a twin-screw extruder, the extrusion temperature of the twin-screw extruder is 180-210 ℃, the length-diameter ratio is (38-42): 1, and the rotating speed is 300-500rpm.
Compared with the prior art, the invention has the beneficial effects that:
(1) The hyperbranched polymer has better adhesive property, and the hyperbranched polymer is added into the polypropylene composition, so that on one hand, the adhesive property of the material can be improved, the material can be directly adhered to metal in molding, a layer of tackifier material is not required to be additionally added, the process is simplified, the cost is saved, and on the other hand, the compatibility of the filler and matrix resin can be improved, and the toughness and rigidity of the material are improved.
(2) In addition, the invention adopts modified montmorillonite, improves the compatibility of montmorillonite and resin, further improves the mechanical property of the polypropylene composition, and improves the bonding property with metal.
Detailed Description
For a better description of the objects, technical solutions and advantages of the present invention, the present invention will be further described with reference to the following specific examples.
Unless specifically stated otherwise, the reagents, methods and apparatus employed in the present invention are those conventional in the art. The reagents and materials used in the present invention are commercially available unless otherwise specified.
The following raw materials are adopted in the examples and comparative examples of the invention:
polypropylene A, with a melt flow rate of 3g/10min at 230 ℃,2.16kg, brand PP K8003, available from the Mao Ming petrochemical industry;
the polypropylene B has a melt flow rate of 1g/10min at 230 ℃ and 2.16kg, and is sold under the brand name PP EPS30R and purchased from the name Mao petrochemical industry;
polypropylene C has a melt flow rate of 5g/10min at 230℃and 2.16kg, and is available from Yanshan petrochemical industry under the brand PP K1005;
The toughening agent A is POE, the melt flow rate measured at 190 ℃ and 2.16kg is 5g/10min, and the brand is POE 7447, which is purchased from DOW;
The toughening agent B is POE, the melt flow rate measured at 190 ℃ and 2.16kg is 0.5g/10min, and the brand is POE 8150, which is purchased from DOW;
the toughening agent C is POE, the melt flow rate measured at 190 ℃ and 2.16kg is 6g/10min, and the brand is POE LC610, which is purchased from LG;
Hyperbranched polymer A, hyperbranched polyester, with a branching degree of 0.5, brand name Hyper H102, purchased from Wuhan hyperbranched;
hyperbranched polymer B, hyperbranched polyester, with a branching degree of 0.6, brand name Hyper H103, purchased from Wuhan hyperbranched;
hyperbranched polymer C, hyperbranched polyester, with a branching degree of 0.7, and a brand of Hyper H104, purchased from Wuhan hyperbranched;
Hyperbranched polymer D, hyperbranched polyester, with a branching degree of 0.4, brand name Hyper H101, purchased from Wuhan hyperbranched;
Hyperbranched polymer E, hyperbranched polyester, with a branching degree of 0.75 and a trade name of Hyper H105, purchased from Wuhan hyperbranched;
Modified montmorillonite A, montmorillonite with surface modified by acidification and quaternary ammonium salt modification, D50 of 3um, DK4-D, purchased from Zhejiang Feng hong;
Modified montmorillonite B, surface modified montmorillonite with acid, D50 of 3um, DK4-S, purchased from Zhejiang Feng hong;
Modified montmorillonite C, montmorillonite with surface modified by quaternary ammonium salt, D50 of 3um, DK4-Y, purchased from Zhejiang Feng hong;
montmorillonite D, which is not modified, D50 is 3um, and the brand is DK4-1, purchased from Zhejiang Feng hong;
the compatilizer is polypropylene grafted maleic anhydride and is commercially available, and the same compatilizer is used in the examples and the comparative examples of the invention;
antioxidant 1010 and antioxidant 168 in the mass ratio of 1 to 1, and the same antioxidant was used in the examples and comparative examples.
Examples 1 to 14 and comparative examples 1 to 5
The components of the polypropylene compositions of examples 1 to 14 of the present invention are shown in Table 1, and the components of the polypropylene compositions of comparative examples 1 to 5 are shown in Table 2.
The preparation methods of the polypropylene composition disclosed by the embodiments 1-9, 11-14 and the comparative examples 2-4 comprise the following steps:
(1) Uniformly mixing a hyperbranched polymer, modified montmorillonite and a compatilizer, and then carrying out melt extrusion granulation to obtain a mixture;
(2) Adding the mixture, the polypropylene resin, the toughening agent and the antioxidant into a double screw for mixing, carrying out melt extrusion and pelleting to obtain the polypropylene composition, wherein the extrusion temperature of a double screw extruder is 180-210 ℃, the length-diameter ratio is 40:1, and the rotating speed is 300-500rpm.
The preparation method of the polypropylene composition of the embodiment 10 of the invention comprises the following steps:
(1) Uniformly mixing a hyperbranched polymer and a compatilizer, and then carrying out melt extrusion granulation to obtain a mixture;
(2) Adding the mixture, the polypropylene resin, the toughening agent and the antioxidant into a double screw for mixing, and carrying out melt extrusion and granulation to obtain the polypropylene composition, wherein the extrusion temperature of a double screw extruder is 180-210 ℃.
The preparation method of the polypropylene composition of the comparative example 1 comprises the following steps:
(1) Uniformly mixing the modified montmorillonite and a compatilizer, and then carrying out melt extrusion granulation to obtain a mixture;
(2) Adding the mixture, the polypropylene resin, the toughening agent and the antioxidant into a double screw for mixing, and carrying out melt extrusion and granulation to obtain the polypropylene composition, wherein the extrusion temperature of a double screw extruder is 180-210 ℃.
The preparation method of the polypropylene composition of the comparative example 5 comprises the following steps:
(1) Uniformly mixing a hyperbranched polymer, unmodified montmorillonite and a compatilizer, and then carrying out melt extrusion granulation to obtain a mixture;
(2) Adding the mixture, the polypropylene resin, the toughening agent and the antioxidant into a double screw for mixing, and carrying out melt extrusion and granulation to obtain the polypropylene composition, wherein the extrusion temperature of a double screw extruder is 180-210 ℃.
TABLE 1
TABLE 2
Effect example
The polypropylene compositions prepared in examples and comparative examples were tested for properties, and specific test items and test methods are as follows:
(1) The impact strength of the cantilever beam is tested according to GB/T1843-2008;
(2) Flexural modulus tested according to standard GB/T9341-2008;
(3) Peel strength test standard GB/T2792-2014 test.
The results of the performance test of the polypropylene compositions described in examples 1 to 14 and comparative examples 1 to 5 are shown in Table 3.
TABLE 3 Table 3
According to the data of Table 3, the polypropylene compositions of examples 1-14 were far superior in Izod impact strength and peel strength to the polypropylene compositions prepared in comparative examples 1-5. According to examples 1-3, the cantilever impact strength, flexural modulus and adhesive property of the material increased with the addition of the hyperbranched polymer, but according to comparative examples 1-3 and examples 1-3, the addition of the hyperbranched polymer according to the present invention can enhance the cantilever impact strength, flexural modulus and adhesive property of the material, but when the addition of the hyperbranched polymer is out of the range defined by the present invention, the cantilever impact strength, flexural modulus and adhesive property of the material decrease. From the data of examples 2, 4-7, it is seen that as the branching degree of the hyperbranched polymer increases, the cantilever impact strength, flexural modulus and adhesion properties of the material increase and then decrease, and that the properties of the material are optimal in the range of 0.5-0.7 branching degree. From the data of examples 2, 8-9 and comparative example 5, it is evident that the modified montmorillonite can significantly enhance the mechanical properties and adhesion properties of the material as compared with the unmodified montmorillonite, and that the montmorillonite subjected to surface acidification modification and quaternary ammonium salt modification has the most significant improvement in the properties of the material. From the data of examples 2 and 10 to 12, it is understood that the cantilever impact strength, flexural modulus and bonding property of the material increase with increasing addition of the modified montmorillonite, but the cantilever impact strength and bonding property of the material significantly decrease with increasing addition beyond the limit of the present invention.
Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted equally without departing from the spirit and scope of the technical solution of the present invention.