Use of ethylene-based polyolefin elastomers for toughening polypropylene

Abstract

The present disclosure provides an application of a vinyl polyolefin elastomer in toughening polypropylene, wherein the vinyl polyolefin elastomer is obtained by catalytic polymerization of ethylene monomer under the action of a nickel catalyst and a cocatalyst; the vinyl polyolefin elastomer has a melt index of 3-13 g / 10 min, a number average molecular weight of 100-800 thousand, a molecular weight distribution of 1.0-2.0, a melting point of 40-80℃, a branching degree of 30-60 / 1000C, and a density of 0.860-0.9 g / cm 3 The present disclosure also provides a toughened polypropylene comprising the vinyl polyolefin elastomer and a preparation method thereof, which effectively enhances the toughness of the polypropylene.

Description

Technical Field

[0001] This disclosure relates to the technical field of polyolefin compound modification, and specifically to the application of a vinyl polyolefin elastomer in toughening polypropylene, and more particularly, to toughened polypropylene comprising a vinyl polyolefin elastomer and a method for preparing the same. Background Technology

[0002] With the rapid development of the automotive industry, polypropylene (PP) materials have been widely used in automotive bumpers, interior parts, dashboards, and headlight bodies due to their good overall performance, low cost, and ease of processing. However, the poor low-temperature toughness and high notch sensitivity of PP materials limit their application range. Therefore, elastomer toughening modification has always been considered the most effective way to improve the shortcomings of PP materials.

[0003] Polyolefin elastomers (POEs) are random copolymers with high α-olefin content obtained by copolymerizing ethylene with α-olefins (such as 1-butene and 1-octene) using metallocene catalysts. Due to the narrow molecular weight distribution of POEs, the side groups in the molecular structure can form bonding points, acting as linkages and buffers between the components. This allows the system to disperse and buffer impact energy upon impact, reducing the chance of crazes developing into cracks under stress, thereby improving the impact strength of polypropylene (PP). Compared with ethylene propylene diene monomer (EPDM), POE toughening modification not only overcomes the poor compatibility between EPDM and PP but also endows PP with higher toughness and better transparency. In recent years, POE has gradually replaced EPDM, becoming the main material for PP modification.

[0004] However, the synthesis of POE requires highly sophisticated technology, with significant technical barriers in multiple stages, including polymerization, catalysts, and α-olefins. The process is complex, and the relevant catalysts are protected by patents; furthermore, there is currently no large-scale production capacity for 1-octene in China. Summary of the Invention

[0005] In view of this, the present disclosure provides an application of a vinyl polyolefin elastomer in toughening polypropylene to at least partially solve the above-mentioned technical problems.

[0006] To solve the above-mentioned technical problems, the technical solution provided in this disclosure is as follows:

[0007] As a first aspect of this disclosure, an application of a vinyl polyolefin elastomer in toughening polypropylene is provided, wherein...

[0008] Vinyl polyolefin elastomers are obtained by catalytic polymerization of ethylene monomers in the presence of nickel-based catalysts and co-catalysts.

[0009] The melt index of vinyl polyolefin elastomers is 3–13 g / 10 min, the number average molecular weight is 100,000–800,000, the molecular weight distribution is 1.0–2.0, the melting point is 40–80 °C, the degree of branching is 30–60 / 1000 °C, and the density is 0.860–0.9 g / cm³. 3 .

[0010] According to embodiments of this disclosure, the nickel-based catalyst includes a diimine nickel metal catalyst having the structure shown below:

[0011]

[0012] Among them, R2, R7, R9, R 12 The elements that are independent of each other are hydrogen, C1-C6 alkyl, halogen, or halogenated C1-C6 alkyl;

[0013] R1 and R8 are independent of each other: hydrogen, C1-C6 alkyl, halogen or halo-C1-C6 alkyl, nitro, C1-C6 alkoxy, trifluoromethyl;

[0014] R3, R6, R 10 R 11 The independent elements are hydrogen, C1-C6 alkyl, halogen or halogenated C1-C6 alkyl, phenyl, and diphenylmethyl;

[0015] R4 and R5 are each independently selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, phenyl, and C6-C30 substituted phenyl.

[0016] X is selected from halogens, C1-C6 alkanes, C2-C6 alkenes, allyl or benzyl.

[0017] According to embodiments of this disclosure, the cocatalyst comprises any one or more of the following: boron salts, alkylaluminoxanes, diethylaluminum chloride, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyl dibenzylaluminum, ethyl di-p-tolylaluminum, and diethylbenzylaluminum;

[0018] Among them, boron salts include any one or more of sodium boron salts, potassium boron salts, lithium boron salts, and cesium boron salts.

[0019] According to embodiments of this disclosure, the molar ratio of the co-catalyst to the nickel-based catalyst is (1-5000):1;

[0020] The temperature for the catalytic polymerization reaction is 30–150℃, the pressure is 0.1–3MPa, and the reaction time is 0.1–78h.

[0021] As a second aspect of this disclosure, a toughened polypropylene is provided, comprising:

[0022] Polypropylene;

[0023] Vinyl polyolefin elastomers; and

[0024] Blending aids;

[0025] Among them, the vinyl polyolefin elastomer is obtained by catalytic polymerization of ethylene monomers under the action of nickel-based catalysts and co-catalysts;

[0026] The melt index of vinyl polyolefin elastomers is 3–13 g / 10 min, the number average molecular weight is 100,000–800,000, the molecular weight distribution is 1.0–2.0, the melting point is 40–80 °C, the degree of branching is 30–60 / 1000 °C, and the density is 0.860–0.9 g / cm³. 3 .

[0027] According to embodiments of this disclosure, the blending additives include: masterbatch, antioxidant, light stabilizer, and lubricant.

[0028] According to embodiments of this disclosure, the toughened polypropylene comprises, by weight parts:

[0029] 100 parts polypropylene, 2-30 parts vinyl polyolefin elastomer, 20-30 parts masterbatch, 0.1-2 parts antioxidant, 0.1-2 parts light stabilizer, and 0.1-2 parts lubricant.

[0030] According to embodiments of this disclosure, the masterbatch is a mixture of talc and polypropylene, wherein the proportion of talc is 50-90%.

[0031] The antioxidant is any one or more of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl) phosphate, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 2,2-oxamido-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, 4,6-bis(octylthiomethyl)o-cresol, and distearyl thiodipropionate.

[0032] The light stabilizer is any one or more of the following: bis-2,2,6,6-tetramethylpiperidinol sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester, bis(1,2,2,6,6-pentamethyl-4-piperidinol) sebacate, bis(2,2,6,6-tetramethyl-4-piperidinol) sebacate, poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl][2-(2,2,6,6-tetramethylpiperidinol)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinol)-imino]}, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, and bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinol) sebacate;

[0033] The lubricant is any one or more of the following: stearic acid, butyl stearate, oleamide, ethylene bis-stearamide, polyethylene wax, and low molecular weight polypropylene.

[0034] As a third aspect of this disclosure, a method for preparing the above-mentioned toughened polypropylene is provided, comprising:

[0035] Weigh out polypropylene, vinyl polyolefin elastomer and blending additives and premix them to obtain a premix;

[0036] The premixed material is extruded and then cooled to increase the notched impact strength of polypropylene, thus obtaining toughened polypropylene.

[0037] According to embodiments of this disclosure, the premixing process is performed at a speed of 800–1500 rpm for 10–20 minutes.

[0038] The temperature of each zone of the extrusion process is 110-210℃, and the rotation speed is 450-550 rpm.

[0039] Based on the above technical solution, the vinyl polyolefin elastomer provided in this disclosure is used for toughening polypropylene. The vinyl polyolefin elastomer obtained by polymerizing ethylene monomers under the action of nickel-based catalysts has a lower cost. When used for toughening polypropylene, this vinyl polyolefin elastomer improves the disadvantage of low notched impact strength of polypropylene and enhances the toughness of the material. It can be used for toughening both homopolymer PP and copolymer PP. The toughened polypropylene material obtained has good heat resistance and mechanical properties, which can meet the requirements of engineering plastic parts in the automotive field and has good application prospects. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments.

[0041] However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments of this disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of this disclosure.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0043] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0044] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). Similarly, when using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0045] In recent years, a method has been developed to prepare long-branched vinyl polyolefin elastomers (E-POE) using only ethylene as a monomer. By using a diimine catalyst with a second-layer coordination space strategy, β-H and β-X elimination reactions can be suppressed, thus achieving good technical results in ethylene homopolymerization and copolymerization of ethylene with polar monomers.

[0046] In the process of realizing this disclosure, it was discovered that asymmetric diimine nickel catalysts and their ligands, possessing high thermal stability and extremely high activity, can produce polyolefin materials with various degrees of branching and high molecular weights in ethylene polymerization; similarly, diimine palladium catalysts and their ligands exhibit high thermal stability and activity in ethylene homopolymerization, and can prepare polyethylene with appropriate degrees of branching and high molecular weights. Furthermore, the polyolefin materials have good compatibility with polypropylene, and can interact with polypropylene at the molecular level to form a uniformly dispersed system, effectively increasing the interfacial area of ​​polypropylene and improving the toughening effect.

[0047] In view of this, the present disclosure provides an application of vinyl polyolefin elastomers in toughening polypropylene, expands the application of vinyl polyolefin elastomers prepared with nickel-based catalysts, and provides a method for toughening polypropylene and its preparation. Specifically, as one aspect of the present disclosure, an application of vinyl polyolefin elastomers in toughening polypropylene is provided, wherein...

[0048] Vinyl polyolefin elastomer (E-POE) is obtained by catalytic polymerization of ethylene monomers in the presence of nickel-based catalysts and co-catalysts;

[0049] The melt index of vinyl polyolefin elastomers is 3–13 g / 10 min, the number average molecular weight is 100,000–800,000, the molecular weight distribution is 1.0–2.0, the melting point is 40–80 °C, the degree of branching is 30–60 / 1000 °C, and the density is 0.860–0.9 g / cm³. 3 .

[0050] According to embodiments of this disclosure, the vinyl polyolefin elastomer has good compatibility with PP and excellent toughening effect on PP. The molecular weight distribution of the vinyl polyolefin elastomer is 1.0 to 2.0, for example, 1.0, 1.2, 1.5, 1.8, 2.0, etc., and the branching degree is 30 to 60 / 1000C, for example, 30 / 1000C, 40 / 1000C, 50 / 1000C, 60 / 1000C, etc., but is not limited to the listed values; other unlisted values ​​within this range are also applicable. Vinyl polyolefin elastomers with molecular weight distribution and branching degree selected within this range have longer side groups in their molecular structure, which can form linkage points in the molecular structure, increasing the physical crosslinking points generated by the interaction of polypropylene molecular chains. This allows the system to play a dispersing and buffering role when subjected to impact, effectively improving the toughness and impact resistance of polypropylene.

[0051] According to embodiments of this disclosure, the melt index of the vinyl polyolefin elastomer is 3 to 13 g / 10 min, for example, it can be 3 g / 10 min, 5 g / 10 min, 9 g / 10 min, 12 g / 10 min, etc., and the melting point can be 45°C, 55°C, 65°C, 75°C, etc., but is not limited to the listed values; other unlisted values ​​within this range are also applicable. Selecting a vinyl polyolefin elastomer with a melt index and melting point within this range facilitates the adjustment of polypropylene flowability and is beneficial for processing and molding.

[0052] According to embodiments of this disclosure, the number average molecular weight of the vinyl polyolefin elastomer is 100,000 to 800,000, for example, it can be 100,000, 150,000, 300,000, 500,000, 750,000, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0053] According to embodiments of this disclosure, the density of the vinyl polyolefin elastomer is 0.860–0.9 g / cm³. 3 For example, it could be 0.86 g / cm³. 3 0.862 g / cm 3 0.865g / cm 3 0.868 g / cm 3 This includes, but is not limited to, the listed values; other unlisted values ​​within this range also apply. A density similar to that of polypropylene can be selected to improve the uniformity of its mixing with polypropylene, facilitate processing, and enhance the flexibility of the polypropylene.

[0054] According to embodiments of this disclosure, the nickel-based catalyst has active catalytic centers capable of catalyzing the polymerization reaction of ethylene monomers. The co-catalyst enhances catalyst activity, regulates reaction rate, and improves the selectivity of the polymerization reaction. By adjusting the combination of the catalyst and co-catalyst and the reaction conditions, the molecular structure, molecular weight, and physical properties of the vinyl polyolefin elastomer can be controlled. Using a nickel-based catalyst to catalyze the polymerization of ethylene monomers yields vinyl polyolefin elastomers (E-POEs) with a backbone linked by carbon-carbon chemical bonds and possessing unbranched, short-branched, and long-branched portions.

[0055] According to embodiments of this disclosure, the nickel-based catalyst includes a diimine nickel metal catalyst having the structure shown below:

[0056]

[0057] Among them, R2, R7, R9, R 12 The elements that are independent of each other are hydrogen, C1-C6 alkyl, halogen, or halogenated C1-C6 alkyl;

[0058] R1 and R8 are independent of each other: hydrogen, C1-C6 alkyl, halogen or halo-C1-C6 alkyl, nitro, C1-C6 alkoxy, trifluoromethyl;

[0059] R3, R6, R 10 R 11 The independent groups are hydrogen, C1-C6 alkyl, halogen or halogenated C1-C6 alkyl, phenyl, diphenylmethyl and their derivatives;

[0060] R4 and R5 are each independently selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, phenyl, and C6-C30 substituted phenyl.

[0061] X is selected from halogens, C1-C6 alkanes, C2-C6 alkenes, allyl or benzyl.

[0062] According to embodiments of this disclosure, the cocatalyst comprises any one or more of the following: boron salts, alkylaluminoxanes, diethylaluminum chloride, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyl dibenzylaluminum, ethyl di-p-tolylaluminum, and diethylbenzylaluminum;

[0063] Among them, boron salts include any one or more of sodium boron salts, potassium boron salts, lithium boron salts, and cesium boron salts.

[0064] According to embodiments of this disclosure, the molar ratio of the co-catalyst to the nickel-based catalyst is (1-5000):1, for example, 1:1, 200:1, 1000:1, 3600:1, 4800:1, etc.; the temperature of the catalytic polymerization reaction is 30-150°C, for example, 30°C, 50°C, 90°C, 120°C, 150°C, etc.; the pressure is 0.1-3 MPa, for example, 0.1 MPa, 0.8 MPa, 1.6 MPa, 2.1 MPa, 2.8 MPa, etc.; and the reaction time is 0.1-78 h, for example, 0.5 h, 8 h, 19 h, 36 h, 59 h, etc. However, it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0065] As a second aspect of this disclosure, a toughened polypropylene is provided, comprising:

[0066] Polypropylene;

[0067] Vinyl polyolefin elastomers; and

[0068] Blending aids;

[0069] Among them, the vinyl polyolefin elastomer is obtained by catalytic polymerization of ethylene monomers under the action of nickel-based catalysts and co-catalysts;

[0070] The melt index of vinyl polyolefin elastomers is 3–13 g / 10 min, the number average molecular weight is 100,000–800,000, the molecular weight distribution is 1.0–2.0, the melting point is 40–80 °C, the degree of branching is 30–60 / 1000 °C, and the density is 0.860–0.9 g / cm³. 3 .

[0071] According to embodiments of this disclosure, the blending additives include: masterbatch, antioxidant, light stabilizer, and lubricant.

[0072] According to embodiments of this disclosure, the toughened polypropylene comprises, by weight parts:

[0073] 100 parts polypropylene, 2-30 parts vinyl polyolefin elastomer, 20-30 parts masterbatch, 0.1-2 parts antioxidant, 0.1-2 parts light stabilizer, and 0.1-2 parts lubricant.

[0074] According to embodiments of this disclosure, when the toughened polypropylene system is subjected to tension, the network structure formed by the bonding points between the vinyl polyolefin elastomer and polypropylene molecules can undergo significant deformation, resulting in a significant increase in the elongation at break of the toughened PP. The vinyl polyolefin elastomer can increase the toughness and elasticity of polypropylene, improving its impact resistance and elongation at break. However, when the content of vinyl polyolefin elastomer increases, the tensile strength, flexural strength, and flexural modulus of the system all decrease.

[0075] According to embodiments of this disclosure, the masterbatch is a mixture of talc and polypropylene, wherein the proportion of talc is 50% to 90%, for example, 50%, 60%, 75%, 85%, etc. By adding the masterbatch as a carrier for the polymer, better dispersibility and stability are provided, allowing the mixing additives to be fully and uniformly mixed with the polypropylene material.

[0076] According to embodiments of this disclosure, adding antioxidants prevents polypropylene from being affected by oxidation during processing and use, thereby extending its service life. The antioxidants added to the toughening polypropylene are any one or more of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl) phosphate, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 2,2-oxamido-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, 4,6-bis(octylthiomethyl)o-cresol, and distearate thiodipropionate.

[0077] According to embodiments of this disclosure, light stabilizers can prevent polypropylene from degrading and aging under sunlight or ultraviolet radiation, thereby improving its weather resistance and lightfastness. The light stabilizer is any one or more of the following: bis-2,2,6,6-tetramethylpiperidinol sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester, bis(1,2,2,6,6-pentamethyl-4-piperidinol) sebacate, bis(2,2,6,6-tetramethyl-4-piperidinol) sebacate, poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl][2-(2,2,6,6-tetramethylpiperidinol)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinol)-imino]}, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, and bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinol) sebacate.

[0078] According to embodiments of this disclosure, adding a lubricant reduces friction between polypropylene particles, improving the flowability and formability of the processing, reducing energy consumption, and minimizing surface defects in the product. The lubricant is any one or more of stearic acid, butyl stearate, oleamide, ethylene bis-stearamide, polyethylene wax, and low molecular weight polypropylene.

[0079] As a third aspect of this disclosure, a method for preparing the above-mentioned toughened polypropylene is provided, comprising:

[0080] Weigh out polypropylene, vinyl polyolefin elastomer and blending additives and premix them to obtain a premix;

[0081] The premixed material is extruded and then cooled to enhance the notched impact strength of polypropylene, thus obtaining toughened polypropylene.

[0082] According to embodiments of this disclosure, polypropylene, vinyl polyolefin elastomer and blending additives are weighed according to the mass ratio of toughened polypropylene, fed into a premixer for premixing at high speed, and then fed into a twin-screw extruder for blending, followed by extrusion and cooling, and then pelletized by a granulator to obtain toughened polypropylene.

[0083] According to embodiments of this disclosure, vinyl polyolefin elastomers have excellent mechanical properties, rheological properties, and UV resistance. The addition of vinyl polyolefin elastomers increases the melt index of the mixture, which can improve the flowability of the material system during preparation and facilitate blending.

[0084] According to embodiments of this disclosure, the premixing speed is 800–1500 rpm, for example, 800 rpm, 1000 rpm, 1200 rpm, 1400 rpm, etc., and the time is 10–20 minutes, for example, 10 minutes, 12 minutes, 15 minutes, 18 minutes, etc. However, it is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0085] According to embodiments of this disclosure, the temperature of each zone in the extrusion process is 110–210°C, for example, 110°C, 140°C, 180°C, 200°C, etc., and the rotation speed is 450–550 rpm, for example, 450 rpm, 480 rpm, 500 rpm, 520 rpm, etc. However, it is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0086] According to embodiments of this disclosure, a screw extruder can be used for extrusion processing, with the following parameters set: machine body temperature 180°C, zone 1 temperature 120±10°C, zone 2 temperature 180±10°C, zone 3 temperature 200±10°C, zone 4 temperature 200±10°C, and main machine speed 500 rpm.

[0087] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions and principles of this disclosure are further illustrated below through specific embodiments. It should be noted that the specific embodiments described below are merely illustrative examples, and the scope of protection of this disclosure is not limited thereto.

[0088] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available. Methods not specifically described in the examples are conventional and can be performed according to the techniques or conditions described in the literature or the product instructions.

[0089] Example 1

[0090] Preparation of vinyl polyolefin elastomers:

[0091] Vinyl polyolefin elastomer (E-POE) is obtained by catalytic polymerization of ethylene monomers in the presence of a nickel-based catalyst and a co-catalyst. Specifically, under a nitrogen atmosphere, a stir bar is added to a 350 mL pressure-resistant bottle, and then methylaluminoxane (MAO) co-catalyst is added at a ratio of 1:250 (nickel-based catalyst to co-catalyst), along with 48 mL of n-hexane solvent for the polymerization reaction of ethylene monomers. The reaction temperature is adjusted to 100 °C, and then 2 mL of dichloromethane solution containing dissolved nickel-based catalyst is injected into the bottle. The ethylene pressure is adjusted to 20 bar, and after the reaction continues for 0.5 hours, a 5% methanol-hydrochloric acid solution is added to precipitate the solid. The solid is washed three times with pure methanol and then dried to obtain vinyl polyolefin elastomer (E-POE).

[0092] The properties of the prepared polyolefin elastomer were tested, and the test results are shown in Table 1.

[0093] Table 1. Performance Comparison of Vinyl Polyolefin Elastomers and Commercially Available POEs

[0094]

[0095] As shown in Table 1, the vinyl polyolefin elastomer (E-POE) prepared in this disclosure is not significantly different from commercially available POE in terms of haze, thickness, and density, but it has a lower melting point, indicating that it is easier to process; and its lower melt index means that the toughened PP has better thermal stability. Furthermore, commercially available polyolefin elastomers require copolymerization of ethylene and α-olefins, while the vinyl polyolefin elastomer in this disclosure is obtained by polymerization using only ethylene monomers as raw materials, eliminating the need for expensive α-olefins. Therefore, the performance-price ratio of the toughened PP with the disclosed vinyl polyolefin elastomer is superior to that of existing polyolefin elastomers.

[0096] Toughened polypropylene is prepared according to the following steps, wherein PP-HY26 polypropylene material is selected:

[0097] (1) Weigh out 100 parts of PP-HY26, 10 parts of E-POE, 25 parts of masterbatch, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.2 parts of antioxidant DSTDP and 0.2 parts of lubricant EBS (P-130) according to the mass fractions and feed them into a premixer. Mix them at high speed at 1500 rpm for 20 minutes to obtain the premix.

[0098] (2) The premixed material is fed into a twin-screw extruder, and the machine body temperature is set to 180℃, zone 1 temperature to 120℃, zone 2 temperature to 180℃, zone 3 temperature to 200℃, and zone 4 temperature to 200℃. The main machine speed is 500 rpm. After the premixed material is blended in the twin-screw extruder and cooled, it is then pelletized in a granulator to obtain toughened polypropylene.

[0099] Example 2

[0100] Toughened polypropylene was prepared using the same method as in Example 1, except that the polypropylene material in Example 1 was replaced with K7227H.

[0101] Example 3

[0102] Toughened polypropylene was prepared using the same method as in Example 2, the only difference being that no masterbatch was added to the premix.

[0103] Comparative Example 1

[0104] Toughened polypropylene was prepared using the same method as in Example 1, except that the vinyl polyolefin elastomer (E-POE) in Example 1 was replaced with Dow 8200.

[0105] Comparative Example 2

[0106] Toughened polypropylene was prepared using the same method as in Comparative Example 1, except that the polypropylene material in Comparative Example 1 was replaced with K7227H.

[0107] The mass fractions of each component of the materials added in Examples 1-3 and Comparative Examples 1 and 2 are shown in Table 2.

[0108] Table 2. Mass fractions of each component in the examples and comparative examples.

[0109]

[0110] The toughened polypropylene prepared in the examples and comparative examples was tested according to the relevant test standards in ISO, and the test results are shown in Table 3.

[0111] Table 3 Comparison of the performance of toughened polypropylene prepared in the examples and comparative examples.

[0112]

[0113] As can be seen from the test results of Example 1 and Comparative Example 1, the toughened polypropylene prepared using E-POE has the same basic properties as commercially available Dow 8200 grade polyolefin elastomer (POE) toughened polypropylene in terms of tensile strength, impact strength, and fracture strain. Furthermore, the Vicat softening temperature and load deformation temperature of the toughened polypropylene prepared using E-POE both exceed those of commercially available Dow 8200 grade polyolefin elastomer toughened polypropylene. It can be seen that the vinyl polyolefin elastomer (E-POE) provided in this disclosure has a wide range of applications.

[0114] As can be seen from the test results of Example 2 and Comparative Example 2, the copolymer PP toughened with E-POE has the same basic properties as commercially available Dow 8200 grade POE-toughened PP in terms of tensile strength, impact strength, and fracture strain. The Vicat softening temperature and load deformation temperature of the copolymer PP material toughened with E-POE both exceed those of commercially available Dow 8200 grade POE-toughened PP.

[0115] Therefore, the vinyl polyolefin elastomer (E-POE) provided in this disclosure can significantly increase the flexural modulus and impact strength of polypropylene materials. It can act as a modifier to improve the insufficient strength of polypropylene and significantly enhance its toughness. Compared with commercially available Dow 8200 grade POE-toughened polypropylene, this material exhibits comparable mechanical properties and even surpasses commercially available Dow 8200 grade POE in terms of thermal stability. The polypropylene toughened with vinyl polyolefin elastomer (E-POE) provided in this disclosure fully meets the requirements for use in automotive engineering plastic parts and can be widely applied in automotive engineering plastic parts, demonstrating broad application prospects.

[0116] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of this disclosure. It should be understood that the above are only specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A toughened polypropylene, comprising, by weight parts: 100 parts polypropylene; 2 to 30 parts of vinyl polyolefin elastomer; and 20-30 parts masterbatch, 0.1-2 parts antioxidant, 0.1-2 parts light stabilizer, and 0.1-2 parts lubricant; in, The vinyl polyolefin elastomer is obtained by catalytic polymerization of a single ethylene monomer in the presence of a diimine nickel metal catalyst and a co-catalyst. The ethylene-based polyolefin elastomer has a melt index of 4.38 g / 10 min, a number average molecular weight of 300,000, a molecular weight distribution of 1.62, a melting point of 42.7 °C, a degree of branching of 60 / 1000 C, a density of 0.860 g / cm 3 ; The masterbatch is a mixture of talc and polypropylene, wherein the proportion of talc is 50-90% and the polypropylene is PP-HY26.

2. The toughened polypropylene according to claim 1, wherein, The diimine nickel metal catalyst has the structure shown in the following formula: wherein R2, R7, R9, R 12 independently of one another are hydrogen, Ci-C6-alkyl, halogen or halogenated Ci-C6-alkyl; R1 and R8 are independent of each other: hydrogen, C1-C6 alkyl, halogen or halo-C1-C6 alkyl, nitro, C1-C6 alkoxy, trifluoromethyl; R3, R6, R 10 R 11 The independent elements are hydrogen, C1-C6 alkyl, halogen or halogenated C1-C6 alkyl, phenyl, and diphenylmethyl; R4 and R5 are each independently selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, phenyl, and C6-C30 substituted phenyl. X is selected from halogens, C1-C6 alkanes, C2-C6 alkenes, allyl or benzyl.

3. The toughened polypropylene according to claim 1, wherein, The cocatalyst comprises any one or more of the following: boron salts, alkylaluminoxanes, diethylaluminum chloride, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldibenzylaluminum, ethyldi-p-tolylaluminum, and diethylbenzylaluminum; The boron salts include any one or more of sodium boron salts, potassium boron salts, lithium boron salts, and cesium boron salts.

4. The toughened polypropylene according to claim 1, wherein, The molar ratio of the co-catalyst to the diimine nickel metal catalyst is (1-5000):1; The catalytic polymerization reaction is carried out at a temperature of 30–150°C, a pressure of 0.1–3 MPa, and a reaction time of 0.1–78 h.

5. The toughened polypropylene according to claim 1, wherein, The antioxidant is any one or more of the following: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl) phosphate, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 2,2-oxamido-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]propionate, 4,6-bis(octylthiomethyl)o-cresol, and distearate thiodipropionate. The light stabilizer is any one or more of the following: bis-2,2,6,6-tetramethylpiperidinol sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester, bis(1,2,2,6,6-pentamethyl-4-piperidinol) sebacate, bis(2,2,6,6-tetramethyl-4-piperidinol) sebacate, poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl][2-(2,2,6,6-tetramethylpiperidinol)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinol)-imino]}, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, and bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinol) sebacate; The lubricant is any one or more of stearic acid, butyl stearate, oleamide, ethylene bis-stearamide, polyethylene wax, and low molecular weight polypropylene.

6. A method for preparing toughened polypropylene as described in any one of claims 1 to 5, comprising: Weigh out polypropylene, vinyl polyolefin elastomer, masterbatch, antioxidant, light stabilizer, and lubricant, and premix them to obtain a premix; The premixed material is extruded and then cooled to increase the notched impact strength of polypropylene, thus obtaining toughened polypropylene.

7. The method according to claim 6, wherein, The premixing process is carried out at a speed of 800–1500 rpm for 10–20 minutes. The temperature of each zone of the extrusion process is 110–210°C, and the rotation speed is 450–550 rpm.

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