CN115785309A - A kind of catalyst for producing reinforced polyethylene and its preparation and application - Google Patents

Abstract

The invention relates to a catalyst for producing reinforced polyethylene and its preparation and application. The carrier catalyst comprises: an inorganic nanocomposite material with a multilayer structure as the first component of the nanocarrier; a reactive magnesium chloride system or a reactive two The silicon oxide system is used as the second component of the nano-carrier, and the above-mentioned two components are fully compounded to form a nano-carrier; the transition metal catalyst is loaded on the nano-carrier to obtain a supported catalyst. In the present invention, due to the existence of a three-dimensional framework uniformly dispersed with nanometer chalcogenides and ultrafine fibers, a supported catalyst is prepared by compounding with an active magnesium chloride system or a silicon dioxide system, which is used for in-situ polymerization self-reinforcement and synergistically reinforced polyolefin compounding The performance of the material, the mechanical properties of the obtained polyethylene composite material has been greatly improved, showing excellent tensile properties, wear resistance and impact resistance and other characteristics.

Description

A kind of catalyst for producing reinforced polyethylene and its preparation and application

technical field

The invention belongs to the technical field of catalyst preparation, and relates to a catalyst for producing reinforced polyethylene and its preparation and application.

Background technique

Polyolefin is the polymer material variety with the largest output and widest application, and is an indispensable basic raw material for national life and modern national defense. The emergence of nanotechnology provides a broad space for the improvement of the performance of polyolefin materials. In nanocomposites, due to the uniform dispersion of nanoscale inorganic dispersed phases in polymers, there are nanoscale effects, large specific surface areas, and strong interfacial interactions. Its performance is often significantly better than that of conventional composite materials with the same components, and it has the advantages of high specific strength, strong designability, and good fatigue resistance, which has a huge impact on promoting the development of polymer material science and the plastics industry. Influence.

Transition metal sulfides MX ₂ , represented by molybdenum disulfide and tungsten disulfide, exhibit excellent anti-friction performance due to their unique microstructure, which uses nano-particle flakes to slow down friction and wear. Molybdenum disulfide is usually added to the substrate for filling modification, compound modification, etc., to improve the performance of polymer or inorganic materials. Patent CN112480578B uses viscose-based carbon fiber, molybdenum disulfide, graphite fluoride and silicone resin powder to blend and modify polytetrafluoroethylene to obtain a cage-shaped skeleton structure polytetrafluoroethylene composite material with excellent performance.

In order to improve the performance of molybdenum disulfide and broaden its application field, it is modified and compounded. Patent CN105304876B prepares graphene/carbon nanofiber airgel by high-temperature carbonization, and then uses a one-step hydrothermal method to in-situ grow molybdenum sulfide nanosheets on graphene/carbon nanofiber airgel. Patent CN107799757B, under hydrothermal conditions, a composite material with a three-dimensional hollow structure of MoS ₂ /nitrogen-doped carbon tubes was prepared. This material obtained excellent cycle performance and rate performance as a negative electrode material for sodium-ion batteries. Patent CN107681142B, prepared porous carbon nanofibers by electrospinning, and then prepared molybdenum disulfide-coated carbon nanofiber composite materials by hydrothermal method, which can improve the poor conductivity of molybdenum disulfide and the charging and discharging process of the battery. Volume expansion problem, improve stability. These methods lack molding additives and coupling agents in the preparation, molybdenum disulfide cannot effectively grow uniformly on the fiber surface, and it is difficult to control the uniformity of the structure of the obtained composite material.

In addition, Chinese patent application CN104558295A discloses a carrier catalyst for producing wear-resistant and flame-retardant polyethylene and its preparation method and application. One component; the chain structure silicate mineral or its modified product as the second component of the nano-carrier; the reactive magnesium chloride system or the reactive silica system as the third component of the nano-carrier, the above two The two components are fully compounded to form a nano-carrier; the transition metal catalyst is supported on the nano-carrier to obtain a supported catalyst. In the preparation process of the composite carrier in this patent, the silicate with layered and chain structures is simply mixed, and an effective three-dimensional structure cannot be formed, and the synergistic enhancement effect of the obtained catalyst and resin performance is relatively weak. At the same time, in addition to silicon and oxygen, most silicate minerals also contain a certain amount of other chemical elements (mainly aluminum, iron, calcium, magnesium, potassium, sodium, etc.), the existence of these substances will affect the activity of the catalyst As well as the characteristics of the obtained resin, the number of trace metal elements in the resin is large and the content exceeds the standard, and the film obtained by processing the resin produces crystal points or defects. Third, the silicates based on silicon and oxygen are weaker than transition metal sulfides represented by molybdenum disulfide due to their own characteristics, wear resistance and reinforcement performance, and cannot achieve the ideal effect in a more severe environment .

Contents of the invention

The object of the present invention is to provide a catalyst for the production of reinforced polyethylene.

Another object of the present invention is to provide a method for preparing a catalyst for producing reinforced polyethylene.

A third object of the present invention is to provide the use of the above catalyst for the production of reinforced polyethylene.

The purpose of the present invention can be achieved through the following technical solutions:

One of the technical solutions of the present invention provides a catalyst for producing reinforced polyethylene, comprising a nano-carrier and a transition metal catalytic component loaded on the nano-carrier, the nano-carrier consists of a first component and a second component The first component is an inorganic nanocomposite material with a multilayer structure, and the second component is a reactive magnesium chloride system or a reactive silicon dioxide system.

Further, the transition metal catalytic component is selected from at least one of Ziegler-Natta catalysts, metallocene catalysts, non-cene early transition metal catalysts or late transition metal catalysts.

Furthermore, the Ziegler-Natta catalyst has the general formula (R'O) _n M'X ₄ , wherein 0≤n<4, and R' is an alkyl, aryl or ring of C ₁ to C ₂₀ Alkyl group; M' is a transition metal of Group 4-6, and X is a halogen compound; the content of the Ziegler-Natta catalyst is 0.1-20wt% of the total amount of the prepared catalyst in terms of metal, and the mass of the electron donor is 100%. Mineral content is 0.01-50%;

More preferably, the Ziegler-Natta catalyst contains a certain amount of electron donors, and the electron donors are organic compounds containing oxygen, nitrogen, phosphorus, sulfur, silicon, etc., preferably monoesters, di One or more compounds such as esters, diethers, succinates, glycol esters, o-phenylenediamines, etc.

The metallocene catalyst has the general formula Cp _x MA _y , wherein x is at least 1, M is a transition metal of Group 4, 5 or 6, and Cp represents an unsubstituted or substituted cyclopentadienyl ligand, an indenyl ligand , fluorenyl ligands, benzoindenyl ligands, dibenzofluorenyl ligands or benzofluorenyl ligands, A is amines, ethers, carboxylic acids, dienes, phosphines, halogens, hydrogen One or more of atoms or alkyl groups, (x+y) is equal to the valence of M, and the content of the metallocene catalyst is 0.01-1mmol/g nanocarrier;

In the non-metallocene early transition metal catalyst, no dicyclopentadiene is contained in the non-metallocene active center, the ligand is an organic group, the ligand atom is O, N, S or P, and the central metal of the metal-organic complex is an anterior Transition metal elements, the former transition metal elements include Ti, Zr, Hf, Cr or V, and the content of the non-procene transition metal catalyst is 0.01-0.1 mmol/g nanocarrier;

The late-transition metal catalyst refers to an olefin polymerization catalyst with high activity for olefin polymerization after being activated by alkylaluminum, alkoxyaluminum or organic boron compound, with the transition metal of Group VIII B as the main catalytic component. The content is 0.01-0.1 mmol/g nano carrier.

More preferably, in the Ziegler-Natta catalyst, M' is titanium, vanadium or zirconium, X is chlorine, bromine or iodine, and the content of the Ziegler-Natta catalyst is calculated as the total amount of the supported catalyst in terms of metal. 0.5-10wt%, the mass percentage of the electron donor is 0.1-5%;;

In the metallocene catalyst, M is zirconium, titanium or hafnium, Cp represents an unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl ligand, and the content of the metallocene catalyst is 0.02-0.6mmol/g nanocarrier ;

Described non-procene transition metal catalyst comprises bishydroxypyridine titanium dichloride catalyst, sulfur bridging bisphenol (TBP) TiCl ₂ , phenoxyimine (salicylaldimine), 8-hydroxyquinoline, chelated One or more of diaminotitanium or azacyclic titanium;

The late transition metal catalyst includes nickel diimide catalyst, pyridine diimide iron (II) or cobalt (II) catalyst; the content of the late transition metal catalyst is 0.02-0.06mmol/g nano carrier.

Further, the reactive magnesium chloride system is an active magnesium oxide obtained by mixing anhydrous magnesium chloride and an electron-donating solvent, and then removing the electron-donating solvent through subsequent treatment.

Further, the reactive silica system is reactive silica obtained by hydrolyzing and condensing silicate or sodium silicate with a silicon-containing organic compound with a reactive group, or silica Reactive silica obtained by mixing acid ester with alkaline reaction medium for sol-gel reaction.

Further, the first component is a three-dimensional composite material composed of chalcogenide-containing compounds and modified reinforcing fibers. Specifically, the specific surface area of the multilayer inorganic nanocomposite material is 5-700m ² /g, and the average pore diameter is It is 1-100 nanometers, and the pore volume is 0.05-500cm ³ /g.

Further, the inorganic nanocomposite material with multilayer structure is prepared through the following steps:

(a) modifying the superfine reinforcing fiber by plasma surface treatment, after washing and neutralizing, adding a coupling agent to obtain the modified reinforcing fiber;

(b) Dissolving the metal source, sulfur source, and molding additive in a solvent, and then performing a hydrothermal reaction with the modified reinforcing fiber obtained in step (a);

(c) washing and drying the hydrothermal product obtained in step (b) to obtain an inorganic nanocomposite material with a multilayer structure.

Furthermore, the plasma surface treatment modification is carried out under inert gas, the temperature is controlled at 70-90° C., and the time is controlled at 6-18 hours.

Further, in step (a), the superfine reinforcing fibers are selected from glass fibers, carbon fibers, basalt fibers, asbestos powder, gypsum fibers, aluminum silicate fibers, ceramic fibers, sepiolite fibers, wollastonite fibers, One or several types of calcium sulfate fibers, the fiber length of which is 0.1-200 microns.

Further, in step (b), the metal source includes a transition metal compound containing titanium, vanadium, tantalum, molybdenum, tungsten or rhenium, preferably sodium molybdate, ammonium molybdate, silicomomolybdic acid, molybdenum oxide, tungstic acid Sodium, ammonium tungstate, tungsten oxide, sodium titanate, barium titanate, titanium powder, vanadium powder, ammonium metavanadate, sodium orthovanadate, vanadium pentoxide, potassium metavanadate, vanadium oxytrichloride, tantalic acid One or more of lithium, ammonium rhenate, potassium rhenate, etc.

Further, in step (b), the sulfur source includes chalcogen compounds containing sulfur, selenium, tellurium, etc., preferably hydrogen sulfide, thioacetamide, thiourea, ammonium tetrathiomolybdate, sulfur powder, One or more of selenium powder, tellurium powder, etc.

Furthermore, in step (b), the molding additive includes one or more of alkyl ammonium halide compounds, molybdosilicic acid and the like. Specifically, the alkylammonium halide compound may be hexadecyltrimethylammonium bromide or the like.

Further, in step (b), the coupling agent includes silane coupling agent, titanate coupling agent, aluminate coupling agent, aluminum zirconate coupling agent, rare earth coupling agent, phosphoric acid ester A combination of one or more of coupling agents or chromium complex coupling agents.

Further, in step (b), the molar ratio of the metal source to the sulfur source is (0.01-100):1, the molar ratio of the molding additive to the metal source is (0.01-100):1, the coupling agent and the metal source The molar ratio of the metal source is (0.01-100):1, and the weight ratio of the metal source to the superfine reinforcing fiber is (0.01-100):1.

Furthermore, in step (b), the temperature of the hydrothermal reaction is 120-360°C; the reaction time is 1-36 hours.

Further, in the catalyst, the mass percentage of the nano-carrier is 70.0-99.99%, and the mass percentage of the transition metal catalytic component is 0.01-30.0%;

The weight ratio of the first component to the second component is (0.01-100):1.

The second technical solution of the present invention provides a preparation method for producing a catalyst for reinforced polyethylene, comprising the following steps:

(1) taking the inorganic nanocomposite material and mixing it with a reactive magnesium chloride system or a reactive silica system to form a magnesium chloride compound or a silica compound comprising the inorganic nanocomposite material;

(2) solidifying the magnesium chloride composite or the silicon dioxide composite to form a nanocarrier comprising inorganic nanocomposites and magnesium chloride or silicon dioxide;

(3) Uniformly loading the transition metal catalytic component on the nano-carrier to prepare the target product.

In the present invention, a certain amount of active components are first dissolved in a solvent, then a certain amount of inorganic nanocarriers are added, the reaction load is fully stirred, and after a certain period of time, a solvent is added to wash several times to remove unreacted active components. Drying under the hood yielded a free-flowing solid catalyst.

The third technical solution of the present invention provides the application of the catalyst for producing reinforced polyethylene, and the catalyst is used as a carrier catalyst for olefin polymerization to produce polyethylene.

Further, when polyethylene is produced, ethylene, α-olefin comonomer, carrier catalyst and co-catalyst are added to the olefin polymerization reactor for polymerization reaction to produce polyethylene. Preferably, the molar ratio of the α-olefin comonomer to ethylene is 0.01-1:1, the concentration of the added carrier catalyst is 0.01-100 ppm, and the concentration of the added co-catalyst is 5-500 ppm.

Preferably, the polymerization reaction is slurry polymerization, solution polymerization or gas phase polymerization, wherein, during slurry polymerization, the reaction pressure is 0.1-5MPa, and the reaction temperature is 0-120°C; during gas phase polymerization, the reaction pressure is 0.5-6MPa, and the reaction temperature is 30-150°C; the polymerization reaction time is 0.05-10.0 hours, preferably 0.05-2.0 hours.

Due to the unique structural characteristics of fibers (length-to-diameter ratio, high strength, etc.), fiber-reinforced composite materials have the advantages of large specific strength and specific modulus, good fatigue resistance, good shock absorption, good overload safety, and good processing performance. Therefore, in order to give full play to the excellent performance of molybdenum sulfide such as wear resistance and self-lubrication, it is necessary to in-situ compound the layered structure of sulfide and inorganic fiber materials. The surface of the fiber is modified by the plasma surface treatment modification technology, and the fiber material and the sulfide of the sheet are compounded in situ by using the molding additive and the coupling agent. Inorganic nanocomposite materials, the two can coordinate and enhance the performance of the composite material, showing the characteristics of good dispersion, strong interaction force and excellent performance. In addition, using nanomaterials as the carrier of olefin polymerization catalysts, loading olefin polymerization active centers on the nano surface or between sheets, and performing in situ olefin polymerization can effectively solve the problems of uneven dispersion and agglomeration in the polymer system.

The invention supports the transition metal catalyst on the spherical multi-dimensional structure composite carrier to carry out the homopolymerization of ethylene or the copolymerization reaction with other comonomers in situ, so as to prepare the polyolefin composite material reinforced by the multi-dimensional structure composite carrier.

Compared with the prior art, the present invention has the following advantages:

(1) The invention utilizes the controlling effect of the molding additive and the molecular bridging effect of the coupling agent to prepare a multi-layer inorganic composite material with superfine reinforcing fibers as the core and sulfide formed in situ as the shell.

(2) The composite material with multi-layer structure can effectively improve the surface affinity of inorganic particles, improve the performance of the reinforced material, and can regulate the structure and shape of the multi-layer sulfide on the surface of the fiber through the amount of molding additives, improve the reinforced performance, and broaden its range. application field.

(3) The present invention focuses on controlling the particle morphology and specific surface area of polyethylene, polypropylene homopolymerization and copolymers thereof reinforced by inorganic nanocomposite carriers of multilayer structure, and provides a kind of high bulk density, fine Method for polyethylene, polypropylene and their copolymers with less powder and non-tackiness. Because polyolefin has a large bulk density, it will not cause the polymer to adhere to the wall of the kettle during the polymerization process, so it is easy to flow and transport, and the production efficiency is improved.

(4) In the polyolefin composite material reinforced by the inorganic nanocomposite carrier of the multilayer structure provided by the present invention, the inorganic nanocomposite carrier of the multilayer structure is a three-dimensional composite material composed of a chalcogenide compound and a modified reinforcing fiber, reactive Magnesium chloride (silicon dioxide) or a mixture of the three in different proportions. Due to the in-situ compounding of ultrafine fibers and multi-layer sulfides, the existence of a three-dimensional skeleton enhances the coordination of the two. After in-situ polymerization, it can form a three-dimensional structure that is evenly dispersed in the polyolefin composite material with enhanced peeling, so that the obtained The material has high mechanical properties and performance at the same time, especially the joint improvement of tensile properties and wear resistance, the simultaneous improvement of toughening and wear resistance, and the synergistic improvement of impact resistance and toughening. It can be seen that the present invention has successfully prepared a polyolefin composite material with high impact resistance and excellent wear resistance through the in-situ polymerization method.

(5) The multi-inorganic nanocomposite carrier-reinforced polyethylene composite material provided by the present invention is used in automotive parts, high wear-resistant pipes and plates, strong barrier hollow containers, packaging materials, barrier materials, flame retardant materials, electrical materials, etc. field and has broad application prospects.

Description of drawings

Figure 1 is a graph showing the relationship between energy dissipation factor and temperature of inorganic composite reinforced polyethylene.

Detailed ways

Specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention. The experimental methods described in the various embodiments of the present invention are conventional methods unless otherwise specified.

The following example method is used to test the performance of the polyethylene resin produced in the described embodiment:

ASTM D1238 is used to test the melt index of polyethylene resin (MI _2.16 , at 2.16kg load, 190°C), flow index (FI, at 21.6kg load, 190°C) and the melt index at 5 kg (MI ₅ , at 5kg load, 190°C); due to the low value of MI _2.16 , the error is relatively large, so the ratio of FI to MI ₅ is used to represent the melt flow ratio of the product, which can qualitatively describe the change of molecular weight distribution.

Polymer molecular weight distribution (MWD) was measured with a PL-220 gel permeation chromatography (GPC) instrument from Polymer Laboratories.

Mechanical properties test The tensile strength and elongation at break of the composite materials were tested on an electronic universal testing machine according to the GB 1040-93 standard. At room temperature, the stretching rate was 50 mm/min. The calculation formula is:

式中，σ_t-拉伸强度，MPa；P-最大载荷，N；b-试样宽度，mm；h-试样厚度，mm。

In the formula, _σt -tensile strength, MPa; P-maximum load, N; b-sample width, mm; h-sample thickness, mm.

The following specific examples explain in detail the inventive catalyst for producing multi-dimensional scale nano-reinforced polyethylene composites and its preparation method. But these examples do not limit the scope of the present invention, nor should it be understood that only the conditions, parameters or values provided by the present invention can implement the present invention. The present invention focuses on the effective control of the morphology of polyethylene polymer particles reinforced by multidimensional nanocomposite carriers, and further regulates the mechanical properties of reinforced nanocomposites, so the obtained multidimensional nanocomposite reinforced polyethylene composites are tested for mechanical properties (testing Enhancement effect of multidimensional nanocomposite supports on tensile properties of polyethylene composites).

Example 1:

Preparation of Ziegler-Natta composite carrier catalyst system;

Example 1a

Preparation of MX2/carbon fiber composites:

(1) First soak 100g of carbon fibers with acetone and ethanol at room temperature, and clean the surface; then treat the carbon fibers with plasma generated at 80°C in an inert gas for 12 hours; then wash the carbon fibers with deionized water until neutral, and transfer to Add 10g of silane coupling agent KH-570 to the stirring reaction kettle lined with polytetrafluoroethylene, stir together and heat at 60°C for 12 hours;

(2) 25g sodium molybdate, 100g hydrogen sulfide and 18g cetyltrimethylammonium bromide are dissolved in deionized water successively to obtain a mixed solution;

(3) Add the mixed solution of step (2) into the stirring reaction kettle of step (1), and continue to stir and heat to 200°C for 24h;

(4) Centrifuge the solution obtained in step (3) to obtain a molybdenum disulfide/carbon fiber composite material.

Preparation of polyethylene composite carrier catalyst:

Under the protection of nitrogen, add 4g of anhydrous magnesium chloride powder, 20ml of absolute ethanol and 50ml of n-heptane into a stirred reaction flask, and stir at 100°C until the magnesium chloride dissolves. Then add 8g of MoS ₂ /carbon fiber composite material powder and stir well for 2 hours. Then cool down to room temperature to obtain the nanocomposite MgCl2·MoS ₂ /carbon fiber·xETOH. Add 17ml of pure triethylaluminum (TEA) to the above system, react at 60°C for 2 hours, add 50ml of n-heptane to wash 4 times to remove unreacted TEA, and dry under vacuum to obtain a carrier Mo with good fluidity. -S.

Take 10g carrier Mo-S, add 50ml n-heptane, 1g 2,3-diisopropyl diethyl succinate and 10ml TiCl ₄ , react at 60°C for 2h, add 50ml n-heptane to wash 4 times to remove unreacted TiCl ₄ , dried under vacuum to obtain a free-flowing solid catalyst Cat-Mo-Ti. The scanning electron micrograph of the composite carrier catalyst is shown in Figure 1.

Slurry polymerization: The reaction device is a 2L steel pressure-resistant water circulating temperature-controlled reactor, add 1L of n-hexane, 50mg of Cat-Mg-Ti catalyst, and 0.5ml of triethylaluminum (cocatalyst), and carry out polymerization at 85°C for 1 hour Afterwards, the reaction was terminated, the temperature was lowered to room temperature, and the material was discharged and dried to obtain a polyethylene product. The catalyst activity was calculated as shown in Table 1. The properties of polypropylene composites after injection molding standard products are shown in Table 2.

The apparent shape of the polyethylene particles reinforced by the multidimensional polycrystalline nanocomposite carrier is spherical, and the particle size is 10-100 microns. The tensile strength and wear resistance of the nanocomposite material have been significantly improved. MoS ₂ / Carbon fiber three-dimensional structural composites enhance the mechanical properties of polyethylene composites.

Example 1b:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to ammonium molybdate, and the sulfur source was changed to thioacetamide. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1c:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to silicomomolybdic acid, and the sulfur source was changed to thiourea. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1d:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to molybdenum oxide, and the sulfur source was changed to ammonium tetrathiomolybdate. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1e:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to sodium tungstate, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1f:

The same method as in Example 1a was used to prepare polyethylene composites, except that the metal source was changed to ammonium tungstate, and the sulfur source was changed to selenium powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1g:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to tungsten oxide, and the sulfur source was changed to tellurium powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1h:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to sodium titanate, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1i:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to barium titanate, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1j:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to titanium powder, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1k:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to vanadium powder, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Embodiment 11:

A polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to ammonium metavanadate, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1m:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to sodium orthovanadate, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1n:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to vanadium pentoxide, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1o:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to potassium metavanadate, and the sulfur source was changed to thiourea. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1p:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to vanadyl trichloride, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1q:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to lithium tantalate, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Example 1r:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to ammonium rhenate, and the sulfur source was changed to thiourea. Calculated catalytic activity and properties of polyethylene resin tested by the above test method

Example 1s:

The polyethylene composite was prepared using the same method as in Example 1a, except that the metal source was changed to potassium rhenate, and the sulfur source was changed to sulfur powder. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 1:

A polyethylene composite was prepared using the same method as in Example 1a, except that cetyltrimethylammonium bromide was not added. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 2

A polyethylene composite material was prepared using the same method as in Example 1a, except that no silane coupling agent KH-570 was added. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 3

A polyethylene composite was prepared using the same method as in Example 1a, except that cetyltrimethylammonium bromide and silane coupling agent KH-570 were not added. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 4

The supported catalyst was prepared using the same method as in Example 1a, except that the MoS ₂ /carbon fiber composite was not added. Slurry polymerization was carried out following the same procedure as in Example 1a. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 5

The supported catalyst was prepared using the same method as in Example 1a, except that no carbon fiber composite material was added. Slurry polymerization was carried out following the same procedure as in Example 1a. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 6:

Compared with Example 1a, most of them are the same, except that the addition of the electron donor diethyl 2,3-diisopropylsuccinate is omitted. Slurry polymerization was carried out following the same procedure as in Example 1a. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 7:

Compared to Example 1a, most are the same, except that the carbon fibers are not plasma-modified. Slurry polymerization was carried out following the same procedure as in Example 1a. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Comparative example 8:

Compared with Example 1a, most of them are the same, except that the addition of sulfur source is omitted during the preparation of carbon fiber composite powder. Slurry polymerization was carried out following the same procedure as in Example 1a. The catalyst activity is shown in Table 1. The properties of polyethylene composites after injection molding standard products are shown in Table 2.

Table 1 Polyethylene catalyst activity and performance of polyethylene composites after injection molding standard products

It can be seen from Table 1 that the tensile strength and impact resistance of the polyethylene resin supported by inorganic composite materials are greatly improved, and the wear resistance of the resin is also improved. It shows that the existence of three-dimensional inorganic composite materials and the addition of molding additives and coupling agents in the preparation process of inorganic materials can help improve the performance of materials. The method of preparing composite materials is unique.

The relationship between energy dissipation factor and temperature of inorganic composite material reinforced polyethylene is shown in Figure 1. Combining with Figure 1, it can be seen that the loss factor tanδ reflects the balance characteristics of the storage modulus and loss modulus of the composite material. The interface performance of the material is better. It can be seen from Figure 1 that compared with the comparative example, the loss factor of the polyethylene reinforced by the inorganic composite material obtained by in-situ polymerization is greatly reduced, and the three-dimensional inorganic composite material can not only absorb dynamic impact energy well, but also It can well transmit the stress to the three-dimensional structural material, thus having excellent comprehensive interfacial bonding performance, and greatly improving the mechanical properties of the resin.

Example 2

Preparation of metallocene nanocarrier catalyst system

Example 2a

The preparation of tungsten disulfide/glass fiber composite material is prepared by the same method as in Example 1a, except that the fiber is changed to glass fiber, the molding additive is changed to a silane coupling agent, and the coupling agent is changed to dodecyltrimethyl ammonium chloride.

Preparation of Polyethylene Composite Support Catalyst

Take 10g of tungsten disulfide/composite glass fiber material carrier and add it to the reaction flask, then add 50ml of toluene solution containing 10% methylaluminoxane (MAO), react at 160°C for 12 hours, and then wash with toluene for 3 times , remove the supernatant. 0.4 g of zirconocene dichloride was added to the toluene suspension containing the above-mentioned MAO-modified multidimensional nanocarrier, and reacted at 0° C. for 6 hours. After the reaction is complete, wash with toluene three times, remove the supernatant, and dry to obtain the metallocene catalyst Cat-Zr supported by the inorganic composite carrier provided by the present invention.

Slurry polymerization: The reaction device is a 2L steel pressure-resistant water circulation temperature-controlled reactor, add 1L of n-hexane, 50mg of Cat-Zr catalyst, and 5ml of triisobutylaluminum n-hexane solution with a weight content of 10%, and carry out polymerization reaction at 75°C After 1 hour, the reaction was terminated, the temperature was lowered to room temperature, and the material was discharged and dried to obtain a polyethylene product. The catalyst activity and the performance of the polyethylene composite material after injection molding a standard product were calculated as shown in Table 2.

Example 2b

The preparation of tungsten disulfide/basalt fiber composite material is prepared by the same method as in Example 1a, except that the fiber is changed to basalt fiber, the molding additive is changed to titanate coupling agent, and the coupling agent is changed to dodecyl Dimethylbenzyl ammonium chloride.

For the preparation of the polyethylene composite carrier catalyst, use the same method as in Example 2a to calculate the catalyst activity and the performance of the polyethylene composite material after injection molding a standard product, as shown in Table 2.

Example 2c

The preparation of tungsten disulfide/asbestos powder/composite material uses the same method as in Example 1a, except that the fiber is changed to asbestos powder, the molding additive is changed to aluminate coupling agent, and the coupling agent is changed to octadecyl dimethyl Hydroxyethylammonium Nitrate.

For the preparation of the polyethylene composite carrier catalyst, use the same method as in Example 2a to calculate the catalyst activity and the performance of the polyethylene composite material after injection molding a standard product, as shown in Table 2.

Example 2d

The preparation method of the tungsten disulfide/aluminum silicate fiber composite material uses the same method as in Example 1a, except that the fiber is changed to aluminum silicate fiber, the forming additive is changed to aluminum zirconate coupling agent, and the coupling agent is changed to ten Octyl Dimethyl Hydroxyethyl Ammonium Perchlorate.

For the preparation of the polyethylene composite carrier catalyst, use the same method as in Example 2a to calculate the catalyst activity and the performance of the polyethylene composite material after injection molding a standard product, as shown in Table 2.

Example 2e

The preparation method of the MoS2/ceramic fiber composite material is the same method as in Example 1a, except that the fiber is changed to /ceramic fiber, the molding additive is changed to a rare earth coupling agent, and the coupling agent is changed to dodecyl silicomolybdic acid.

For the preparation of the polyethylene composite carrier catalyst, use the same method as in Example 2a to calculate the catalyst activity and the performance of the polyethylene composite material after injection molding a standard product, as shown in Table 2.

Example 2f

The preparation method of tungsten disulfide/sepiolite fiber composite material uses the same method as in Example 1a, except that the fiber is changed to sepiolite fiber, the molding additive is changed to a phosphate coupling agent, and the coupling agent is changed to a decanyl Molybdosilicate.

For the preparation of the polyethylene composite carrier catalyst, use the same method as in Example 2a to calculate the catalyst activity and the performance of the polyethylene composite material after injection molding a standard product, as shown in Table 2.

Example 2g

The preparation method of tungsten disulfide/wollastonite fiber composite material uses the same method as in Example 1a, except that the fiber is changed to wollastonite fiber, the forming additive is changed to chromium complex coupling agent, and the coupling agent is changed to silicon Sodium acid.

For the preparation of the polyethylene composite carrier catalyst, use the same method as in Example 2a to calculate the catalyst activity and the performance of the polyethylene composite material after injection molding a standard product, as shown in Table 2.

Example 2h

The preparation method of the molybdenum disulfide/calcium sulfate fiber composite material uses the same method as in Example 1a, except that the fiber is changed to calcium sulfate fiber.

For the preparation of the polyethylene composite carrier catalyst, use the same method as in Example 2a to calculate the catalyst activity and the performance of the polyethylene composite material after injection molding a standard product, as shown in Table 2.

It can be seen from Table 2 that the polyethylene composites obtained by the metallocene catalyst system also exhibit excellent reinforcement properties. The existence of three-dimensional inorganic composites, as well as the addition of molding additives and coupling agents during the preparation of inorganic materials, contribute to Improve the performance of materials. Compared with the comparative example, the three-dimensional structure of the inorganic composite material has excellent comprehensive interface bonding performance, which greatly improves the mechanical properties of the resin.

Table 2 Polyethylene catalyst activity and performance of polyethylene composites after injection molding standard products

Example 3

Preparation of non-procene transition metal catalysts;

Synthesis of bis(2-pyridinoxy)titanium dichloride catalyst (bis(2-pyridinoxy)titanium dichloride):

Under nitrogen protection, dissolve 0.03mol of 2-hydroxypyridine and 0.03mol of triethylamine in 50ml of tetrahydrofuran, stir for 1 hour, then slowly add 0.015mol of titanium tetrachloride dropwise at 0°C, and stir at room temperature for 24 hours . The supernatant liquid of tetrahydrofuran was sucked off, and the solvent was distilled off under reduced pressure to obtain a catalyst, which was a bishydroxypyridine titanium dichloride catalyst, with a yield of 80.0%.

Preparation of multidimensional polysilicate composite carrier catalyst:

Get the tungsten disulfide/carbon fiber material carrier that 10g embodiment 1a prepares and join in the reaction bottle, then add the toluene solution containing 10% methylaluminoxane (MAO) of 80ml, react at 120 ℃ for 12 hours, then use toluene Wash 3 times. Then 5ml of toluene solution of bishydroxypyridine titanium dichloride (titanium concentration 8×10 ^-6 mol/ml) was added, and reacted at 60°C for 2 hours. After the reaction is complete, wash with toluene three times, remove the supernatant, and dry to obtain the non-pre-transition metallocene catalyst supported by the multidimensional polysilicate composite carrier provided by the present invention.

Slurry polymerization: the reaction device is a 2L steel pressure-resistant water circulation temperature-controlled reactor, respectively add 1L of n-hexane, 100mg of the catalyst obtained above, 4ml of 10% triisobutylaluminum, and then replace ethylene for 4 times, remove nitrogen, and replenish Inject ethylene under a pressure of 0.8MPa, and carry out polymerization at 85°C. After reacting for 1 hour, the reaction was terminated, the temperature was lowered to room temperature, and the material was discharged and dried to obtain a polyethylene product. The calculated catalyst activity and the performance of the polyethylene composite material after injection molding a standard product were shown in Table 2.

Example 4:

Preparation of nano-carrier post-transition metal catalysts;

Synthesis of pyridinediimine iron-based catalysts:

Synthesis of ligand 2,6-bis(1-(2,6-diisopropylanilinoethyl))pyridine

Dissolve 3g (18.4mmol) of 2,6-diacetylpyridine and 13g (73.6mmol) of 2,6-diisopropylaniline in 50ml of absolute ethanol, add 5 drops of glacial acetic acid, and heat to reflux for 48h. The system was cooled to room temperature, crystallized at -18°C, filtered with suction, washed with cold alcohol, dried, and weighed to obtain 7.98g of solid, which was 2,6-bis(1-(2,6-diisopropylaniline Base ethyl)) pyridine, the yield was 90.0%.

Catalyst Synthesis

Under the protection of nitrogen, 2.1 mmol of the above ligand and 2 mmol of FeCl ₂ ·4H ₂ O were added to a 100 ml Schlenk bottle, 30 ml of tetrahydrofuran was added, and the reaction was stirred at 30° C. for 3 hours. After the reaction is finished, n-hexane is added dropwise, the catalyst is precipitated and filtered, and washed several times with n-hexane and ether to obtain a pyridinediimide iron-based catalyst.

Preparation of multidimensional polysilicate composite carrier catalyst:

Get a certain amount of tungsten disulfide/carbon fiber material carrier prepared in Example 1a and add it to the reaction flask, then add 80ml of toluene solution containing 10% methylaluminoxane (MAO), react at 120°C for 12 hours, and then Wash 3 times with toluene. Then 5ml of the toluene solution (iron concentration 8×10 ^-6 mol/ml) of the above prepared pyridinediimide iron-based catalyst was added, and reacted at 60°C for 2 hours. After the reaction is complete, wash with toluene for 3 times, remove the supernatant, and dry to obtain the late transition metal catalyst supported by the multidimensional nano-carrier provided by the present invention.

Slurry polymerization: the reaction device is a 2L steel pressurized water circulation temperature control reactor, add 1L of n-hexane, 50mg of the catalyst obtained above, and 5ml of triisobutylaluminum (10%), and carry out the polymerization reaction at 85°C for 1 hour. The reaction was terminated, the temperature was lowered to room temperature, the material was discharged, and dried to obtain a polyethylene product. The catalyst activity and the performance of the polyethylene composite material after injection molding a standard product were calculated as shown in Table 2.

Example 5:

Preparation of Ziegler-Natta composite carrier catalyst system:

Take 10g of the tungsten disulfide/carbon fiber material carrier prepared in Example 1a and add it into the reaction flask, and disperse it in ethanol through ultrasonic action. , dropwise added 0.5ml of ethyl orthosilicate. The reaction was continued for 15 hours, and then the solvent was removed, and the inorganic composite carrier particles Si-S containing silicon dioxide were obtained after drying, with an average particle diameter of about 10-100 microns.

Take 10g carrier Si-S, add 50ml n-heptane, 0.5g di-n-butyl phthalate and 10ml TiCl ₄ , react at 60°C for 2h, add 50ml n-hexane to wash 4 times to remove unreacted TiCl ₄ , Drying under vacuum gave a free-flowing solid catalyst.

Slurry polymerization: The reaction device is a 2L steel pressure-resistant water circulation temperature-controlled reactor, add 1L of n-hexane, 50mg of the catalyst obtained above, and 0.5ml of triethylaluminum, and carry out the polymerization reaction at 85°C for 1 hour, then terminate the reaction and lower the temperature to room temperature, discharge, and dry to obtain a polyethylene product. The calculated catalyst activity and the performance of the polyethylene composite material after injection molding a standard product are shown in Table 2.

Embodiment 6:

Compared with Example 1a, most of them are the same, except for the control in this example: the molar ratio of metal source to sulfur source is 0.01:1, the molar ratio of molding additive to metal source is 100:1, coupling agent and The molar ratio of metal sources is 100:1.

Embodiment 7:

Compared with Example 1a, most of them are the same, except for the control in this example: the molar ratio of metal source to sulfur source is 100:1, the molar ratio of molding additive to metal source is 0.01:1, coupling agent and The molar ratio of metal sources is 0.01:1.

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (10)

1. A catalyst for producing enhanced polyethylene, which is characterized by comprising a nano-carrier and a transition metal catalytic component loaded on the nano-carrier, wherein the nano-carrier is formed by compounding a first component and a second component, the first component is an inorganic nano-composite material with a multilayer structure, and the second component is a reactive magnesium chloride system or a reactive silicon dioxide system.

2. The catalyst for producing enhanced polyethylene of claim 1 wherein said transition metal catalytic component is selected from at least one of ziegler-natta, metallocene, non-metallocene pre-transition metal, or post-transition metal catalysts.

3. The catalyst for producing enhanced polyethylene according to claim 1, wherein the first component is a three-dimensional composite material in which a sulfur group-containing compound and modified reinforcing fibers are compounded;

the reactive magnesium chloride system is active magnesium oxide obtained by mixing anhydrous magnesium chloride and an electron donor solvent and then removing the electron donor solvent through subsequent treatment;

the reactive silicon dioxide system is reactive silicon dioxide obtained by hydrolysis and condensation reaction of silicate ester or sodium silicate and a silicon-containing organic compound with a reactive group, or reactive silicon dioxide obtained by mixing silicate ester and an alkaline reaction medium and carrying out sol-gel reaction.

4. The catalyst for producing enhanced polyethylene according to claim 1, wherein the inorganic nanocomposite material having a multilayer structure is prepared by the steps of:

(a) Modifying the superfine reinforced fiber by adopting plasma surface treatment, washing to be neutral, and then adding a coupling agent for treatment to obtain modified reinforced fiber;

(b) Dissolving a metal source, a sulfur source and a forming additive in a solvent, and carrying out hydrothermal reaction on the metal source, the sulfur source and the forming additive and the modified reinforced fiber obtained in the step (a);

(c) And (c) washing and drying the hydrothermal product obtained in the step (b) to obtain the inorganic nano composite material with a multilayer structure.

5. The catalyst for producing reinforced polyethylene according to claim 4, wherein the ultrafine reinforcing fibers are selected from one or more of glass fibers, carbon fibers, basalt fibers, asbestos powder, gypsum fibers, aluminum silicate fibers, ceramic fibers, sepiolite fibers, wollastonite fibers and calcium sulfate fibers, and the fiber length of the ultrafine reinforcing fibers is 0.1-200 microns;

the metal source comprises a transition metal compound comprising titanium, vanadium, tantalum, molybdenum, tungsten, or rhenium;

the sulfur source includes a chalcogen compound containing sulfur, selenium, tellurium, etc.;

the forming additive comprises one or more of alkyl ammonium halide compounds and silicomolybdic acid;

the coupling agent comprises one or more of silane coupling agent, titanate coupling agent, aluminate coupling agent, aluminum zirconate coupling agent, rare earth coupling agent, phosphate coupling agent or chromium complex coupling agent.

6. The catalyst for producing enhanced polyethylene of claim 4, wherein in step (b), the molar ratio of the metal source to the sulfur source is (0.01-100): 1, the molar ratio of the forming additive to the metal source is (0.01-100): 1, the molar ratio of the coupling agent to the metal source is (0.01-100): 1, the weight ratio of the metal source to the superfine reinforcing fiber is (0.01-100) to 1;

in the step (b), the temperature of the hydrothermal reaction is 120-360 ℃; the reaction time is 1-36 hours.

7. The catalyst for producing enhanced polyethylene according to claim 1, wherein the nano-carrier is 70.0-99.99% by mass, and the transition metal catalytic component is 0.01-30.0% by mass;

the weight ratio of the first component to the second component is (0.01-100): 1.

8. process for the preparation of a catalyst for the production of enhanced polyethylene according to any one of claims 1 to 7, comprising the steps of:

(1) Mixing the inorganic nanocomposite material with a reactive magnesium chloride system or a reactive silica system to form a magnesium chloride composite or a silica composite containing the inorganic nanocomposite material;

(2) Curing the resulting magnesium chloride composite or silica composite to form a nanocarrier comprising the inorganic nanocomposite and magnesium chloride or silica;

(3) And uniformly loading the transition metal catalytic component on the nano-carrier to prepare the target product.

9. Use of a catalyst for the production of enhanced polyethylene according to any one of claims 1 to 7 as a supported catalyst for the polymerization of olefins to produce polyethylene.

10. Use of a catalyst according to claim 9 for the production of enhanced polyethylene, wherein in the production of polyethylene ethylene, an α -olefin comonomer, a supported catalyst and a cocatalyst are added to an olefin polymerization reactor for polymerization to produce polyethylene, wherein the molar ratio of said α -olefin comonomer to ethylene is in the range of from 0.01 to 1:1, the concentration of the added carrier catalyst is 0.01-100ppm, and the concentration of the added cocatalyst is 5-500ppm.

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