Surface scratch-resistant polypropylene composite material and preparation method thereof

Abstract

The invention discloses a surface scratch-resistant polypropylene composite material which is prepared from the following components in parts by weight: 60-80 parts of polypropylene resin, 20-40 parts of talcum powder, 3-5 parts of a compatilizer, 5-10 parts of modified molybdenum disulfide and 0.2-1 part of a processing aid. The modified molybdenum disulfide is treated by a silane coupling agent and grafted by styrene; a polymer brush structure is formed on the surface of molybdenum disulfide. According to the surface scratch-resistant polypropylene composite material prepared by the invention, through surface modification, a polymer chain segment similar to polypropylene in structure is introduced to the surface of molybdenum disulfide, and maleic anhydride grafted polypropylene is used as a compatilizer, so that a strong interaction is formed between molybdenum disulfide and polypropylene in a compounding process; the compatibility of modified molybdenum disulfide and polypropylene is effectively improved, and uniform dispersion of molybdenum disulfide in a polypropylene matrix is realized.

Description

Technical Field

[0001] The invention relates to the technical field of polymer material modification, in particular to a surface scratch-resistant polypropylene composite material and a preparation method thereof. Background Art

[0002] As a general-purpose thermoplastic, polypropylene (PP) has been widely used in many fields such as automobile manufacturing, home appliance production, packaging industry and daily necessities due to its good comprehensive properties, such as low density, strong chemical stability, easy processing and molding, and low cost. However, polypropylene materials themselves have some inherent defects, among which low surface hardness and poor scratch resistance are more prominent problems. In actual use, polypropylene products are easily scratched by external objects, resulting in obvious scratches, which not only seriously affects the appearance quality of the product, reduces the beauty and commercial value of the product, but also may damage the integrity of the product surface, thereby affecting its physical properties and service life, limiting the application expansion of polypropylene in high-end fields with strict requirements on surface quality.

[0003] At present, in order to improve the scratch resistance of polypropylene, the existing technology mainly adopts methods such as adding fillers, blending modification and surface treatment. Although adding ordinary inorganic fillers can improve the hardness to a certain extent, it often leads to a decrease in the toughness and processing performance of polypropylene; in blending modification, the compatibility between different polymers is difficult to ensure, and phase separation is prone to occur, affecting the comprehensive performance of the material; although the surface treatment method has significant effects, the process is complicated, the cost is high, and the durability of the treated surface is limited. Therefore, it is of great practical significance and market demand to develop a simple, efficient, low-cost modification method that can significantly improve the scratch resistance of polypropylene without affecting its other excellent properties. Summary of the invention

[0004] In view of this, the present invention provides a surface scratch-resistant polypropylene composite material and a preparation method thereof, in order to solve the problems raised in the above-mentioned background technology. By performing unique surface modification on molybdenum disulfide and adopting a novel composite process, the compatibility between the modified molybdenum disulfide and polypropylene is effectively improved, and the molybdenum disulfide is evenly dispersed in the polypropylene matrix, thereby significantly improving the surface scratch resistance of the polypropylene-based composite material and maintaining high mechanical properties, thereby solving the deficiencies in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention discloses a surface scratch-resistant polypropylene composite material, which is prepared from the following components in parts by weight:

[0007]

[0008] The modified molybdenum disulfide is treated with a silane coupling agent and grafted with styrene, so that a polymer brush structure is formed on the surface of the molybdenum disulfide.

[0009] As a further solution of the present invention: the polypropylene resin is at least one of homopolypropylene and copolymer polypropylene.

[0010] As a further solution of the present invention: the compatibilizer is ethylene-methyl acrylate-glycidyl methacrylate copolymer.

[0011] As a further solution of the present invention: the talcum powder has a particle size of 3000-5000 mesh.

[0012] As a further solution of the present invention: the preparation method of the modified molybdenum disulfide is as follows:

[0013] (1) immersing molybdenum disulfide in an ethanol solution of a silane coupling agent, stirring and reacting in a water bath at 50-70° C., to obtain molybdenum disulfide having an organic film of unsaturated double bonds on the surface;

[0014] (2) mixing the molybdenum disulfide treated in step (1) with styrene and an initiator, reacting for 3-5 hours under nitrogen protection at 80-100° C. to obtain modified molybdenum disulfide.

[0015] As a further solution of the present invention: in step (2), the mass ratio of the treated molybdenum disulfide to styrene is (2-4):1, and the amount of the initiator used is 1%-2% of the mass of the styrene. By controlling the styrene grafting amount (mass ratio) and the reaction time, the density and length of the polymer brush are adjusted, so that styrene can grow and synthesize well on the surface of molybdenum disulfide, thereby improving the dispersibility of molybdenum disulfide and the compatibility with polypropylene materials.

[0016] As a further solution of the present invention: the ethanol solution of the silane coupling agent is an ethanol solution of γ-methacryloxypropyltrimethoxysilane with a mass fraction of 3%-5%.

[0017] As a further solution of the present invention: the processing aid is at least one of an antioxidant, a light absorber, and a light stabilizer.

[0018] On the other hand, the present invention discloses a method for preparing the above-mentioned surface scratch-resistant polypropylene composite material, comprising the following steps:

[0019] The polypropylene resin, talcum powder, compatibilizer, modified molybdenum disulfide and processing aid are weighed and mixed uniformly according to weight, and then added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to finally obtain a scratch-resistant polypropylene composite material.

[0020] As a further solution of the present invention: the barrel temperature of the twin-screw extruder is -160°C-300°C, the mold temperature is 300-320°C, the screw speed is 250-300r / min, the melt pressure is 1.0-1.2MPa, and the vacuum degree is -0.06MPa.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention prepares a surface scratch-resistant polypropylene composite material, through surface modification, introduces a polymer segment similar to the structure of polypropylene on the surface of molybdenum disulfide, and uses maleic anhydride grafted polypropylene as a compatibilizer, and during the composite process, a strong interaction is formed between the two, which effectively improves the compatibility of the modified molybdenum disulfide and polypropylene, and realizes the uniform dispersion of molybdenum disulfide in the polypropylene matrix. Good compatibility enables molybdenum disulfide to fully exert its reinforcing effect, and the prepared polypropylene-based composite material is significantly improved in mechanical properties (tensile strength, bending strength, impact strength, etc.), wear resistance, scratch resistance, etc., and broadens the application field of polypropylene. DETAILED DESCRIPTION

[0023] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0026] Polypropylene resin, brand K7100, melt index 100g / 10min, manufacturer: Yanshan Petrochemical.

[0027] Talc powder, specification model KC6300, 2500 mesh, manufacturer: Beihai, Liaoning.

[0028] The compatibilizer is EMA-GMA, brand: BF-7M, grafting rate 8%, manufacturer: Sumitomo, Japan.

[0029] Molybdenum disulfide, color: black powder, manufacturer: Shandong Luxing Chemical Co., Ltd.

[0030] Initiator, dibenzoyl peroxide, brand: Aksu CH-50, manufacturer: Wanqing Chemical Technology Co., Ltd.;

[0031] The processing aid is compounded by lubricant, primary antioxidant, secondary antioxidant, light absorber and light stabilizer in a mass ratio of 10:1:1:1:1. Among them, the lubricant is silicone masterbatch with brand MB50-002, produced by Dow Corning of the United States; the primary antioxidant is Irganox 565, produced by BASF of Germany; the secondary antioxidant is AN 168, produced by Qingdao Deda Special Chemical Group; the light absorber is Chiguard 5050, produced by Qitai Co., Ltd.; the light stabilizer is LA-52, produced by Aidico (China) Investment Co., Ltd.

[0032] All materials are commercially available common products.

[0033] It is to be understood that the above raw materials and reagents are only examples of some specific embodiments of the present invention, so that the technical solution of the present invention is clearer, and it does not mean that the present invention can only use the above reagents, and the specific scope in the claims shall prevail. In addition, the "parts" described in the examples and comparative examples, unless otherwise specified, refer to parts by weight.

[0034] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0035] Example 1

[0036] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto. The mixture is stirred at a speed of 200-300r / min for 2-3 hours in a water bath at 60°C, and then the molybdenum disulfide treated with a silane coupling agent is filtered, washed, and dried, and then added to a reactor containing styrene and benzoyl peroxide initiator. The mass ratio of styrene to molybdenum disulfide is 2:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0037] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer, 5 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0038] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0039] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0040] Example 2

[0041] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto. The mixture is stirred at a speed of 200-300r / min for 2-3 hours in a water bath at 60°C, and then the molybdenum disulfide treated with a silane coupling agent is filtered, washed, and dried, and then added to a reactor containing styrene and benzoyl peroxide initiator. The mass ratio of styrene to molybdenum disulfide is 3:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0042] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer, 8 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0043] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0044] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0045] Example 3

[0046] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto. The mixture is stirred at a speed of 200-300r / min for 2-3 hours in a water bath at 60°C, and then the molybdenum disulfide treated with a silane coupling agent is filtered, washed, and dried, and then added to a reactor containing styrene and benzoyl peroxide initiator. The mass ratio of styrene to molybdenum disulfide is 4:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0047] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer, 10 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0048] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0049] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0050] Example 4

[0051] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto. The mixture is stirred at a speed of 200-300r / min for 2-3 hours in a water bath at 60°C, and then the molybdenum disulfide treated with a silane coupling agent is filtered, washed, and dried, and then added to a reactor containing styrene and benzoyl peroxide initiator. The mass ratio of styrene to molybdenum disulfide is 3:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0052] Weigh 70 parts of polypropylene resin, 30 parts of talc, 3 parts of compatibilizer, 10 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0053] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0054] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0055] Example 5

[0056] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto. The mixture is stirred at a speed of 200-300r / min for 2-3 hours in a water bath at 60°C, and then the molybdenum disulfide treated with a silane coupling agent is filtered, washed, and dried, and then added to a reactor containing styrene and benzoyl peroxide initiator. The mass ratio of styrene to molybdenum disulfide is 3:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0057] Weigh 60 parts of polypropylene resin, 40 parts of talc, 3 parts of compatibilizer, 10 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0058] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0059] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0060] Comparative Example 1

[0061] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0062] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0063] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0064] Comparative Example 2

[0065] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer, 5 parts of molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0066] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0067] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0068] Comparative Example 3

[0069] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto, followed by styrene and benzoyl peroxide initiator, wherein the mass ratio of styrene to molybdenum disulfide is 2:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0070] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer, 5 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0071] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0072] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0073] Comparative Example 4

[0074] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto. The mixture is stirred at a speed of 200-300r / min for 2-3 hours in a water bath at 60°C, and then the molybdenum disulfide treated with a silane coupling agent is filtered, washed, and dried, and then added to a reactor containing styrene and benzoyl peroxide initiator. The mass ratio of styrene to molybdenum disulfide is 1.5:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0075] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer, 5 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0076] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0077] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0078] Comparative Example 5

[0079] The molybdenum disulfide powder is placed in a vacuum drying oven and dried at 80-100°C for 4-6 hours to remove moisture and impurities. An ethanol solution of γ-methacryloxypropyltrimethoxysilane (KH-570) with a mass fraction of 3%-5% is prepared, and the dried molybdenum disulfide powder is added thereto. The mixture is stirred at a speed of 200-300r / min for 2-3 hours in a water bath at 60°C, and then the molybdenum disulfide treated with a silane coupling agent is filtered, washed, and dried, and then added to a reactor containing styrene and benzoyl peroxide initiator. The mass ratio of styrene to molybdenum disulfide is 4.5:1, and the amount of benzoyl peroxide is 1.5% of the mass of styrene. Under nitrogen protection, the reaction system is heated to 80-100°C and reacted for 3-5 hours to obtain modified molybdenum disulfide.

[0080] Weigh 80 parts of polypropylene resin, 20 parts of talc, 3 parts of compatibilizer, 10 parts of modified molybdenum disulfide and 1 part of processing aid, add them into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0081] The premix is ​​added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to obtain a surface scratch-resistant polypropylene composite material.

[0082] Among them, the barrel temperature of the twin-screw extruder is 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280 in zone 5, and 300°C in zone 6; the mold temperature is 300°C, the screw speed is 500r / min, the melt pressure is 1.0MPa, and the vacuum degree is -0.06MPa.

[0083] Test Case

[0084] The surface scratch-resistant polypropylene composite materials prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were respectively put into an injection molding machine for melting, and standard samples and shrinkage plates with a size of 200 mm*140 mm*2.5 mm were respectively prepared for scratch resistance testing; the barrel temperature of the injection molding machine was 220°C and the mold temperature was 60°C.

[0085] The tensile properties, bending properties and impact properties of the injection-molded marked samples of the surface scratch-resistant polypropylene composite materials prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were tested. The scratch resistance was tested by the cross-hatch method, using a spherical scratch head with a diameter of 0.5±0.01 mm, a scratch force of 15 N, a test speed of 1000±50 mm / min, and 20 tests in one direction with a spacing of 2 mm; the scratch result was judged by testing the color difference △L before and after the scratch. The smaller the △L, the better the scratch resistance.

[0086] The test results are shown in Table 1.

[0087] Table 1

[0088]

[0089] It can be seen from Table 1 that the scratch resistance of the surface scratch-resistant polypropylene composite material in Comparative Example 1 is poor. After adding 5 parts of molybdenum disulfide in Comparative Example 2, the surface scratch resistance is slightly improved, but due to the poor compatibility of molybdenum disulfide with polypropylene, there is agglomeration, and the mechanical properties of the material are reduced. In Comparative Examples 3 to 5, since molybdenum disulfide does not utilize the alkoxy group of silane to condense with the surface hydroxyl group of molybdenum disulfide to form an organic film containing double bonds, it lacks the reaction site for subsequent styrene free radical grafting, so the surface modification effect is not good, and the compatibility with polypropylene is poor, resulting in poor mechanical properties of the material. In Examples 1 to 5, when modified molybdenum disulfide is added to the polypropylene composite material, since the surface of molybdenum disulfide introduces polymer segments similar to the structure of polypropylene, and maleic anhydride is grafted onto polypropylene as a compatibilizer, a strong interaction is formed between the two during the composite process, which effectively improves the compatibility of modified molybdenum disulfide with polypropylene and realizes the uniform dispersion of molybdenum disulfide in the polypropylene matrix. Good compatibility enables molybdenum disulfide to fully exert its reinforcing effect. The prepared polypropylene-based composite material has good scratch resistance and maintains high mechanical properties (tensile strength, flexural strength, impact strength, etc.), broadening the application field of polypropylene composite materials.

[0090] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0091] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A surface scratch-resistant polypropylene composite material, characterized in that: It is prepared from the following components in parts by weight: The modified molybdenum disulfide is treated with a silane coupling agent and grafted with styrene, so that a polymer brush structure is formed on the surface of the molybdenum disulfide.

2. The surface scratch-resistant polypropylene composite material according to claim 1, characterized in that: The polypropylene resin is at least one of homopolypropylene and copolymer polypropylene.

3. The surface scratch-resistant polypropylene composite material according to claim 1, characterized in that: The compatibilizer is ethylene-methyl acrylate-glycidyl methacrylate copolymer.

4. The surface scratch-resistant polypropylene composite material according to claim 1, characterized in that: The talcum powder has a particle size of 3000-5000 mesh.

5. The surface scratch-resistant polypropylene composite material according to claim 1, characterized in that: The preparation method of the modified molybdenum disulfide is as follows: (1) immersing molybdenum disulfide in an ethanol solution of a silane coupling agent, stirring and reacting in a water bath at 50-70° C., to obtain molybdenum disulfide having an organic film of unsaturated double bonds on the surface; (2) mixing the molybdenum disulfide treated in step (1) with styrene and an initiator, reacting for 3-5 hours under nitrogen protection at 80-100° C. to obtain modified molybdenum disulfide.

6. The surface scratch-resistant polypropylene composite material according to claim 5, characterized in that: In step (2), the mass ratio of the treated molybdenum disulfide to styrene is (2-4):1, and the amount of the initiator used is 1%-2% of the mass of the styrene.

7. The surface scratch-resistant polypropylene composite material according to claim 5, characterized in that: The ethanol solution of the silane coupling agent is an ethanol solution of gamma-methacryloxypropyltrimethoxysilane with a mass fraction of 3%-5%.

8. The surface scratch-resistant polypropylene composite material according to claim 1, characterized in that: The processing aid is at least one of an antioxidant, a light absorber, and a light stabilizer.

9. The method for preparing the surface scratch-resistant polypropylene composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polypropylene resin, talcum powder, compatibilizer, modified molybdenum disulfide and processing aid are weighed and mixed uniformly according to weight, and then added into a twin-screw extruder for melt blending and extrusion, and then cooled and pelletized to finally obtain a scratch-resistant polypropylene composite material.

10. The preparation method according to claim 9, characterized in that: The barrel temperature of the twin-screw extruder is -160°C-300°C, the mold temperature is 300-320°C, the screw speed is 250-300r / min, the melt pressure is 1.0-1.2MPa, and the vacuum degree is -0.06MPa.

Images