A high-weather-resistant ABS composite material and preparation method thereof

Abstract

The present invention belongs to the technical field of polymer composite materials, specifically relating to a highly weather-resistant ABS composite material and its preparation method. The composite material comprises the following components, by weight: 90-100 parts of ABS matrix, 1.2-1.5 parts of aminopropylated nano-SiO2, 2-3 parts of waterborne polyurethane, 1.2-1.8 parts of acrylic emulsion, 0.25-0.35 parts of polyethylene wax, 0.2-0.25 parts of antioxidant, and 0.7-0.8 parts of UV absorber. The present invention grafts glycidyl methacrylate onto the ABS to promote covalent bonding of the -NH2 with the aminopropylated SiO2, achieving stable dispersion of the nanoparticles. The surface is treated with H2O2 / APTES to form a gradient cross-linked interface, enhancing coating adhesion. A waterborne polyurethane-acrylic acid system is used as the topcoat, combining bulk and surface SiO2 for dual protection, significantly enhancing weather resistance, corrosion resistance, and mechanical stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer composite materials, and particularly relates to a highly weather-resistant ABS composite material and a preparation method thereof. Background Art

[0002] In modern industry and everyday life, ABS (acrylonitrile-butadiene-styrene) composites are widely used in automotive, electronics, construction, and household appliances due to their excellent processing properties, superior mechanical strength, and excellent electrical insulation properties. However, with the increasing diversity and complexity of application environments, the use of ABS composites in outdoor and harsh environments faces significant challenges. In particular, under harsh climate conditions such as UV radiation, high temperature, high humidity, and salt spray, ABS materials are susceptible to aging, discoloration, cracking, and strength loss, seriously affecting their service life and aesthetics. Due to limitations in existing technologies, traditional ABS materials are susceptible to photooxidation under prolonged UV exposure, resulting in surface yellowing, embrittlement, and even cracking, limiting their use in outdoor decoration and applications requiring high weather resistance. Extreme temperature and humidity fluctuations also affect the performance stability of ABS materials, leading to dimensional changes and a decrease in mechanical properties, compromising their effectiveness. In corrosive environments such as salt spray, ABS materials are susceptible to chemical attack, causing surface corrosion and reduced strength, impacting their durability and safety. Although some modified ABS materials have been developed to improve weather resistance by adding light stabilizers and antioxidants, these methods often focus on improving a single property and lack a comprehensive protection mechanism, making it difficult to comprehensively enhance the material's weather resistance. Therefore, given these shortcomings, it is extremely necessary to develop an ABS composite material with excellent high and low temperature resistance, outstanding corrosion resistance, and stable performance. Summary of the Invention

[0003] In view of the defects of the prior art, the object of the present invention is to provide a highly weather-resistant ABS composite material and a preparation method thereof.

[0004] The technical effect of the present invention is achieved through the following technical solution: a high-weather-resistant ABS composite material, comprising the following components by weight: 90 to 100 parts of ABS matrix, 1.2 to 1.5 parts of aminopropylated nano-SiO2, 2 to 3 parts of water-based polyurethane, 1.2 to 1.8 parts of acrylic emulsion, 0.25 to 0.35 parts of polyethylene wax, 0.2 to 0.25 parts of antioxidant and 0.7 to 0.8 parts of UV absorber.

[0005] Preferably, the ABS matrix is ​​composed of 95-97 wt% ABS and 3-5 wt% epoxy-grafted ABS;

[0006] Preferably, the preparation steps of the epoxy grafted ABS are as follows:

[0007] S1: ABS is vacuum dried at 100°C for 3-4 hours to obtain dry ABS; glycidyl methacrylate is placed in a sealed drying container and filtered through a 0.45µm filter to remove impurities; dry ABS, peroxide, AO-1010, and dodecanethiol are premixed at 300rpm for 3-5 minutes to obtain ABS material;

[0008] S2: The ABS material from step S1 is fed into a twin-screw extruder. After stabilization, vacuum is turned on, and glycidyl methacrylate after impurity removal in step S1 is continuously injected from the side feed port of Zone 2; the temperature is maintained at 200-205°C, and glycidyl methacrylate is grafted with the main chain free radicals in Zone 2-3; mixing is performed in Zone 4; the vacuum degree in Zone 5 is -80-100 kPa, and unreacted GMA and by-product small molecules are removed simultaneously. The extruder is extruded, cooled in a water tank at 20°C, blown dry, and vacuum-dried at 80°C for 3-6 hours to obtain epoxy-grafted ABS;

[0009] Preferably, in step S1, the peroxidant is any one of di-tert-butyl peroxide and dicumyl peroxide;

[0010] Preferably, in step S1, the mass ratio of the dried ABS, peroxidant, AO-1010 and dodecanethiol is 1:0.005-0.007:0.001:0.003-0.004;

[0011] Preferably, in step S2, the mass ratio of the ABS material to glycidyl methacrylate is 1:0.06-0.08;

[0012] Preferably, the preparation steps of the aminopropylated nano-SiO2 are as follows:

[0013] S101: SiO2 was added to a 95 wt% ethanol solution and dispersed evenly by ultrasonic treatment. Glacial acetic acid was added dropwise to adjust the pH to 4.3-4.7. 3-Aminopropyltriethoxysilane was slowly added dropwise at a rate of 1 mL / min under nitrogen protection at 30°C. After the addition was complete, the temperature was raised to 40°C and stirred at 300 rpm for 30-60 min.

[0014] S102: After completing step S101, the temperature was raised to 80°C, refluxed for 4-6 hours, and continuously purged with nitrogen. The mixture was centrifuged at 8000 rpm for 10 minutes, and washed alternately with anhydrous ethanol and 80 wt% ethanol solution for 3 times. The mixture was vacuum dried at 80°C for 12-16 hours to obtain nano-aminopropylated SiO2.

[0015] Preferably, in step S101, the ratio of the amount of SiO2 to the ethanol solution is 1 g: 15-20 mL;

[0016] Preferably, in step S101, the ratio of the amount of SiO2 and 3-aminopropyltriethoxysilane is 1g:0.6-0.7mL;

[0017] Preferably, the antioxidant is composed of AO-1010 and AO-168 in a mass ratio of 1:2;

[0018] Preferably, the UV absorber is any one of UV531 and HALS-770;

[0019] Preferably, another aspect of the present invention is to provide a method for preparing a highly weather-resistant ABS composite material, comprising the following preparation steps:

[0020] S201: vacuum drying the ABS substrate at 80°C for 3-6 hours to obtain pretreated ABS and pretreated epoxy-grafted ABS, and drying the aminopropylated nano-SiO2 at 80°C for 2-4 hours to obtain pretreated aminopropylated nano-SiO2;

[0021] S202: The pretreated epoxy-grafted ABS prepared in step S201 and 80% of the total weight of pretreated aminopropylated nano-SiO2 are premixed and dispersed uniformly in a high-speed mixer, and then added to a twin-screw extruder at 180-190° C., 150 rpm, and a vacuum of -70-90 kPa for 120-150 seconds to prepare SiO2 masterbatch.

[0022] S203: Raise the temperature to 180-190°C, add the pretreated ABS from step S201, polyethylene wax, antioxidant, and UV absorber into a twin-screw extruder at a screw speed of 200-250 rpm, add the SiO2 masterbatch from step S202 into the side feeder, blend at 190-200°C, degas under vacuum at -90-95 kPa, extrude, cool in a water tank at 20°C, blow dry, and dehumidify under vacuum at room temperature for 24 hours to obtain ABS material;

[0023] S204: The ABS material prepared in step S203 is injection molded at a barrel temperature of 195-200°C, a mold temperature of 70-75°C, an injection pressure of 80-100 MPa, and a holding time of 20-30 seconds, and then naturally cooled for 24 hours;

[0024] S205: After completing the treatment in step S204, immerse the substrate in a 0.5 wt% APTES solution for 30-40 seconds and dry it at 60°C for 5-10 minutes; then coat it with a waterborne polyurethane-acrylic acid composite solution to a thickness of 30-40 μm, dry it at 80°C for 10-15 minutes, and dry it at 100°C for 20-30 minutes to obtain an ABS composite material;

[0025] Preferably, in step S205, the APTES solution is prepared by adding 3-aminopropyltriethoxysilane to an 80 wt % ethanol solution and adding 1 wt % hydrogen peroxide;

[0026] Preferably, in step S205, the aqueous polyurethane-acrylic acid composite solution is prepared by uniformly mixing aqueous polyurethane, acrylic acid emulsion and the remaining weight portion of aminopropylated nano-SiO2 by ultrasonic dispersion, and adjusting the solid content to 35wt% by deionized water.

[0027] The beneficial effects of the present invention are as follows:

[0028] The present invention first utilizes epoxy grafting of glycidyl methacrylate to modify ABS (E-ABS). During the blending and cooling process, the epoxy grafted segments spontaneously accumulate on the material surface, significantly increasing the surface epoxy group density. The high-density epoxy can undergo a β-hydroxyamine ring-opening reaction with the -NH2 on the surface of aminopropylated SiO2 and also undergo addition reactions with hydroxyl and amine groups in subsequent dip coatings or topcoats, thereby establishing a stable chemically bonded interface from the source. During the masterbatch preparation stage, SiO2 nanoparticles containing -NH2 on their surfaces are directly introduced into the epoxy-grafted ABS. The amine groups on the particles covalently bond with the epoxy ring-opening, achieving long-term dispersion stability without the need for secondary interfacial agents. The epoxy grafted phase is molecularly compatible with the parent ABS, refining the rubber phase size and reducing interfacial tension. Thus, impact toughness and processing fluidity are maintained without the introduction of additional macromolecular compatibilizers. This structure provides ample sites for subsequent silane condensation and amine-epoxy ring-opening reactions while also preventing loss of toughness and fluidity within the matrix. The prepared SiO2 masterbatch is then blended and diluted with conventional ABS. The particles are covalently fixed and evenly dispersed in the initial stage. Subsequent dilution does not destroy the particle-segment bonding, nor does it significantly increase the matrix melt viscosity, thus achieving both processing stability and barrier properties. After forming, the surface of the material is impregnated with an APTES solution containing a low concentration of hydrogen peroxide. The hydrogen peroxide gently oxidizes the butadiene segments to generate polar functional groups such as hydroxyl (-OH) and carboxyl (-COOH). These functional groups react with the APTES silanol groups hydrolyzed in the same bath to form a gradient cross-linked interface from the surface to the inside, significantly improving the polarity of the substrate surface and the adhesion of the primer, and enhancing the coating's resistance to thermal shock and shear. Finally, the top coat uses a water-based polyurethane-acrylic emulsion system. The polyurethane soft segment and the acrylic hard segment form a network through hydrogen bonds and van der Waals forces, achieving good flexibility and weather resistance. Aminopropylated SiO2 nanoparticles in the bulk phase inhibit dielectric penetration and UV energy conduction; similar particles in the topcoat further reduce surface moisture and ion flux, weakening radiation intensity. Spatially separated, the two levels of particles complement each other, creating a dual protection mechanism that significantly enhances the material's weathering and corrosion resistance, as well as its long-term mechanical stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 1 is a graph showing the impact strength retention rate of the ABS substrate weathering test of Example 3 of the present invention, Comparative Examples 1 to 4, and the control group;

[0031] Figure 2 1. This is a graph showing the gloss retention results of the weather resistance test of the ABS substrate of Example 3 of the present invention, Comparative Examples 1 to 4, and the control group;

[0032] Figure 3 1 is a graph showing the water vapor transmission rate test results of ABS substrates of Example 3 of the present invention, Comparative Examples 1 to 4, and a control group;

[0033] Figure 4 This is the FTIR infrared spectrum of the epoxy grafted ABS material prepared in Example 3 of the present invention;

[0034] Figure 5 This is a SEM scanning electron microscope image of the ABS composite material prepared in Example 3 of the present invention after weather resistance testing;

[0035] Figure 6 This is a SEM scanning electron microscope image of the ABS composite material prepared in Comparative Example 3 of the present invention after weather resistance testing. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. It should be noted that unless otherwise specified, the raw materials involved in the present invention were purchased through conventional commercial channels.

[0037] Example 1: A highly weather-resistant ABS composite material comprises the following components, in parts by weight: 90 parts of ABS matrix, 1.2 parts of aminopropylated nano-SiO2, 2 parts of waterborne polyurethane, 1.2 parts of acrylic emulsion, 0.25 parts of polyethylene wax, 0.2 parts of antioxidant and 0.7 parts of UV absorber.

[0038] The ABS matrix is ​​composed of 97wt% ABS and 3wt% epoxy-grafted ABS;

[0039] The preparation steps of the epoxy grafted ABS are as follows:

[0040] S1: ABS was vacuum dried at 100°C for 3 h to obtain dry ABS; glycidyl methacrylate was placed in a sealed drying container and filtered through a 0.45 µm filter to remove impurities; 1000 g of dry ABS, 5 g of di-tert-butyl peroxide, 1 g of AO-1010, and 3 g of dodecanethiol were premixed at 300 rpm for 3 min to obtain ABS material;

[0041] S2: 1000g of ABS material from step S1 was added to a twin-screw extruder. After stabilization, vacuum was applied and 60g of glycidyl methacrylate, which had been cleaned in step S1, was continuously injected from the side feed port of Zone 2. The temperature was maintained at 200°C, and glycidyl methacrylate was grafted with the main chain free radicals in Zone 2-3. Mixing was performed in Zone 4. The vacuum degree in Zone 5 was set to -80kPa to remove unreacted GMA and by-product small molecules. The product was extruded, cooled in a water tank at 20°C, dried, and vacuum dried at 80°C for 3h to obtain epoxy-grafted ABS.

[0042] The preparation steps of the aminopropylated nano-SiO2 are as follows:

[0043] S101: Add 5 g of SiO2 to 75 mL of 95 wt% ethanol solution and disperse evenly with ultrasonic treatment. Add glacial acetic acid dropwise to adjust the pH to 4.7. Under nitrogen protection at 30°C, slowly add 3 mL of 3-aminopropyltriethoxysilane dropwise at a rate of 1 mL / min. After the addition is complete, heat to 40°C and stir at 300 rpm for 30 min.

[0044] S102: After completing step S101, the temperature was raised to 80°C, refluxed for 4 hours, and continuously purged with nitrogen. The mixture was centrifuged at 8000 rpm for 10 minutes, and washed alternately with anhydrous ethanol and 80 wt% ethanol solution for 3 times. The mixture was vacuum dried at 80°C for 12 hours to obtain nano-aminopropylated SiO2.

[0045] The preparation of high weather resistance ABS composite material includes the following steps:

[0046] S201: The ABS substrate is vacuum dried at 80°C for 3 hours to obtain pretreated ABS and pretreated epoxy-grafted ABS, and the aminopropylated nano-SiO2 is dried at 80°C for 2 hours to obtain pretreated aminopropylated nano-SiO2;

[0047] S202: The pretreated epoxy-grafted ABS prepared in step S201 and 80% of the total weight of pretreated aminopropylated nano-SiO2 are premixed and dispersed uniformly in a high-speed mixer, and then added to a twin-screw extruder at 180°C, 150 rpm, vacuum -70 kPa, and a dwell time of 120 seconds to prepare SiO2 masterbatch.

[0048] S203: The temperature was raised to 180°C, and the pretreated ABS of step S201, polyethylene wax, an antioxidant consisting of AO-1010 and AO-168 in a mass ratio of 1:2, and HALS-770 were added to a twin-screw extruder at a screw speed of 200 rpm. The SiO2 masterbatch of step S202 was added through a side feed port, and the mixture was blended at 190°C, degassed under a vacuum of -90 kPa, extruded, cooled in a water tank at 20°C, dried, and subjected to vacuum dehumidification at room temperature for 24 hours to obtain an ABS material.

[0049] S204: The ABS material prepared in step S203 is injection molded at a barrel temperature of 195°C, a mold temperature of 70°C, an injection pressure of 80 MPa, and a holding time of 20 seconds, and then naturally cooled for 24 hours;

[0050] S205: After completing the treatment of step S204, use a 0.5wt% APTES solution obtained by adding 3-aminopropyltriethoxysilane to an 80wt% ethanol solution and adding 1% by mass of hydrogen peroxide to obtain a solution, immerse for 30s, and dry at 60℃ for 5min; then use a water-based polyurethane, acrylic emulsion and the remaining weight portion of aminopropylated nano-SiO2 to evenly mix with ultrasonic dispersion, and adjust the solid content to 35wt% with deionized water to obtain a water-based polyurethane-acrylic composite solution, with a thickness of 30μm, treat at 80℃ for 10min, and treat at 100℃ for 20min to obtain an ABS composite material.

[0051] Example 2: A highly weather-resistant ABS composite material comprises the following components, in parts by weight: 100 parts of ABS matrix, 1.5 parts of aminopropylated nano-SiO2, 3 parts of waterborne polyurethane, 1.8 parts of acrylic emulsion, 0.35 parts of polyethylene wax, 0.25 parts of antioxidant and 0.8 parts of UV absorber.

[0052] The ABS matrix is ​​composed of 96 wt% ABS and 4 wt% epoxy-grafted ABS;

[0053] The preparation steps of the epoxy grafted ABS are as follows:

[0054] S1: ABS was vacuum dried at 100°C for 4 h to obtain dry ABS; glycidyl methacrylate was placed in a sealed drying container and filtered through a 0.45 µm filter to remove impurities; 1000 g of dry ABS, 7 g of dicumyl peroxide, 1 g of AO-1010, and 4 g of dodecanethiol were premixed at 300 rpm for 5 min to obtain ABS material;

[0055] S2: 1000g of ABS material from step S1 was added to a twin-screw extruder. After stabilization, vacuum was applied and 80g of glycidyl methacrylate, which had been cleaned from step S1, was continuously injected from the side feed port of Zone 2. The temperature was maintained at 203°C, and glycidyl methacrylate was grafted with the main chain free radicals in Zone 2-3. Mixing was performed in Zone 4. The vacuum degree in Zone 5 was set to -90kPa to remove unreacted GMA and by-product small molecules. The product was extruded, cooled in a water tank at 20°C, dried, and vacuum dried at 80°C for 6h to obtain epoxy-grafted ABS.

[0056] The preparation steps of the aminopropylated nano-SiO2 are as follows:

[0057] S101: Add 5 g of SiO2 to 100 mL of 95 wt% ethanol solution and disperse evenly with ultrasonic treatment. Add glacial acetic acid dropwise to adjust the pH to 4.3. Under nitrogen protection at 30°C, slowly add 3.5 mL of 3-aminopropyltriethoxysilane dropwise at a rate of 1 mL / min. After the addition is complete, heat to 40°C and stir at 300 rpm for 60 min.

[0058] S102: After completing step S101, the temperature was raised to 80°C, refluxed for 6 hours, and continuously purged with nitrogen. The mixture was centrifuged at 8000 rpm for 10 minutes, and washed alternately with anhydrous ethanol and 80 wt% ethanol solution for 3 times. The mixture was vacuum dried at 80°C for 16 hours to obtain nano-aminopropylated SiO2.

[0059] The preparation of high weather resistance ABS composite material includes the following steps:

[0060] S201: The ABS substrate is vacuum dried at 80°C for 6 hours to obtain pretreated ABS and pretreated epoxy grafted ABS, and the aminopropylated nano-SiO2 is dried at 80°C for 4 hours to obtain pretreated aminopropylated nano-SiO2;

[0061] S202: The pretreated epoxy-grafted ABS prepared in step S201 and 80% of the total weight of pretreated aminopropylated nano-SiO2 are premixed and dispersed uniformly in a high-speed mixer, and then added to a twin-screw extruder at 190°C, 150 rpm, vacuum -90 kPa, and held for 150 seconds to prepare SiO2 masterbatch.

[0062] S203: The temperature was raised to 190°C, and the pretreated ABS of step S201, polyethylene wax, an antioxidant consisting of AO-1010 and AO-168 in a mass ratio of 1:2, and HALS-770 were added to a twin-screw extruder at a screw speed of 250 rpm. The SiO2 masterbatch of step S202 was added through a side feed port, and the mixture was blended at 200°C, vacuum degassed at -92 kPa, extruded, cooled in a water tank at 20°C, blown dry, and vacuum dehumidified at room temperature for 24 hours to obtain an ABS material.

[0063] S204: The ABS material prepared in step S203 is injection molded at a barrel temperature of 200°C, a mold temperature of 75°C, an injection pressure of 100 MPa, and a holding time of 30 seconds, and then naturally cooled for 24 hours;

[0064] S205: After completing the treatment of step S204, use a 0.5wt% APTES solution obtained by adding 3-aminopropyltriethoxysilane to an 80wt% ethanol solution and adding 1% by mass of hydrogen peroxide to obtain a solution, immerse for 40s, and dry at 60℃ for 10min; then use a water-based polyurethane, acrylic emulsion and the remaining weight portion of aminopropylated nano-SiO2 to ultrasonically disperse and evenly mix, and adjust the solid content to 35wt% with deionized water to obtain a water-based polyurethane-acrylic composite solution, with a thickness of 40μm, treat at 80℃ for 15min, and treat at 100℃ for 30min to obtain an ABS composite material.

[0065] Example 3: A highly weather-resistant ABS composite material comprises the following components, in parts by weight: 95 parts of ABS matrix, 1.4 parts of aminopropylated nano-SiO2, 2.8 parts of waterborne polyurethane, 1.6 parts of acrylic emulsion, 0.32 parts of polyethylene wax, 0.24 parts of antioxidant and 0.75 parts of UV absorber.

[0066] The ABS matrix is ​​composed of 95wt% ABS and 5wt% epoxy-grafted ABS;

[0067] The preparation steps of the epoxy grafted ABS are as follows:

[0068] S1: ABS was vacuum dried at 100°C for 3.5 hours to obtain dry ABS; glycidyl methacrylate was placed in a sealed drying container and filtered through a 0.45µm filter to remove impurities; 1000g of dry ABS, 6g of di-tert-butyl peroxide, 1g of AO-1010, and 3.5g of dodecanethiol were premixed at 300rpm for 4 minutes to obtain ABS material;

[0069] S2: 1000g of ABS material from step S1 was added to a twin-screw extruder. After stabilization, vacuum was applied and 75g of glycidyl methacrylate, which had been cleaned from step S1, was continuously injected from the side feed port of Zone 2. The temperature was maintained at 205°C, and glycidyl methacrylate was grafted with the main chain free radicals in Zone 2-3. Mixing was performed in Zone 4. The vacuum degree in Zone 5 was set to -100kPa to remove unreacted GMA and by-product small molecules. The extruder was extruded, cooled in a water tank at 20°C, dried, and vacuum dried at 80°C for 5h to obtain epoxy-grafted ABS.

[0070] The preparation steps of the aminopropylated nano-SiO2 are as follows:

[0071] S101: Add 5 g of SiO2 to 90 mL of 95 wt% ethanol solution and disperse evenly with ultrasonic treatment. Add glacial acetic acid dropwise to adjust the pH to 4.5. Under nitrogen protection at 30°C, slowly add 3.3 mL of 3-aminopropyltriethoxysilane dropwise at a rate of 1 mL / min. After the addition is complete, heat to 40°C and stir at 300 rpm for 50 min.

[0072] S102: After completing step S101, the temperature was raised to 80°C, refluxed for 5 hours, and continuously purged with nitrogen. The mixture was centrifuged at 8000 rpm for 10 minutes, and washed alternately with anhydrous ethanol and 80 wt% ethanol solution for 3 times. The mixture was vacuum dried at 80°C for 15 hours to obtain nano-aminopropylated SiO2.

[0073] The preparation of high weather resistance ABS composite material includes the following steps:

[0074] S201: The ABS substrate is vacuum dried at 80°C for 5 hours to obtain pretreated ABS and pretreated epoxy grafted ABS, and the aminopropylated nano-SiO2 is dried at 80°C for 3 hours to obtain pretreated aminopropylated nano-SiO2;

[0075] S202: The pretreated epoxy-grafted ABS prepared in step S201 and 80% of the total weight of pretreated aminopropylated nano-SiO2 are premixed and dispersed uniformly in a high-speed mixer, and then added to a twin-screw extruder at 185°C, 150 rpm, vacuum -80 kPa, and a dwell time of 140 seconds to prepare SiO2 masterbatch.

[0076] S203: Raise the temperature to 185°C, add the pretreated ABS from step S201, polyethylene wax, an antioxidant consisting of AO-1010 and AO-168 in a mass ratio of 1:2, and UV531 into a twin-screw extruder at a screw speed of 230 rpm, add the SiO2 masterbatch from step S202 into the side feed, blend at 195°C, degas under -95 kPa vacuum, extrude, cool in a water tank at 20°C, blow dry, and dehumidify under vacuum at room temperature for 24 hours to obtain ABS material;

[0077] S204: The ABS material prepared in step S203 is injection molded at a barrel temperature of 198°C, a mold temperature of 72°C, an injection pressure of 90 MPa, and a holding time of 25 seconds, and then naturally cooled for 24 hours;

[0078] S205: After completing the treatment of step S204, use a 0.5wt% APTES solution obtained by adding 3-aminopropyltriethoxysilane to an 80wt% ethanol solution and adding 1% by mass of hydrogen peroxide to obtain a solution, immerse for 35s, and dry at 60℃ for 8min; then use a water-based polyurethane, acrylic emulsion and the remaining weight portion of aminopropylated nano-SiO2 to evenly mix with ultrasonic dispersion, and adjust the solid content to 35wt% with deionized water to obtain a water-based polyurethane-acrylic composite solution, with a thickness of 35μm, treat at 80℃ for 12min, and treat at 100℃ for 28min to obtain an ABS composite material.

[0079] Comparative Example 1: The operating process parameters of Comparative Example 1 and Example 3 are basically the same, the main difference is that epoxy-grafted ABS is not added in Comparative Example 1.

[0080] Comparative Example 2: The operating process parameters of Comparative Example 2 and Example 3 are basically the same, the main difference is that conventional nano-SiO2 is used to replace aminopropylated nano-SiO2 in Comparative Example 2.

[0081] Comparative Example 3: The operating process parameters of Comparative Example 3 and Example 3 are basically the same, the main difference is that in Comparative Example 3, the APTES solution with a concentration of 1 wt% hydrogen peroxide is replaced by the APTES solution with a concentration of 5 wt% hydrogen peroxide.

[0082] Comparative Example 4: The operating process parameters of Comparative Example 4 and Example 3 are basically the same. The main difference is that in Comparative Example 4, epoxy-grafted ABS and aminopropylated SiO2 are directly added to the main blending system without masterbatch preparation.

[0083] Performance testing:

[0084] Mechanical properties test: The ABS composite material samples prepared in Examples 1 to 3 and Comparative Examples 1 to 4 and the control group (ABS matrix material) were subjected to the following tests. The tensile strength and elongation at break were measured in accordance with GB / T 1040.1-2018; the flexural strength was measured in accordance with GB / T 9341-2008; and the impact strength was measured using a plastic pendulum impact tester in accordance with GB / T 1843-2008. Each test was performed three times in parallel, and the results were averaged. The test results are shown in Table 1 below.

[0085] Table 1. Mechanical properties test results of ABS composite materials and control group ABS materials

[0086]

[0087] As can be seen from the results in Table 1, compared with the pure ABS material in the control group, the mechanical properties of the embodiment of the present invention are significantly improved by optimizing the interface compatibility between the resin matrix and the reinforcement phase and adopting a multi-component synergistic toughening mechanism, especially in terms of tensile strength, flexural strength and impact strength. As can be seen from the results of Comparative Example 1, the impact strength and flexural strength are significantly reduced, which may be due to the lack of epoxy grafting, resulting in only physical bonding between the particles and the matrix, interface debonding, agglomeration, etc., resulting in a significant decrease in flexural strength and impact strength. As can be seen from the results of Comparative Example 2, the various forces The mechanical properties of the composites have all declined to a certain extent, which may be due to the fact that SiO2 has no -NH2 grafting and is difficult to react with epoxy, resulting in particle agglomeration and slightly poor dispersibility. The results of Comparative Example 3 show that the mechanical properties have declined significantly, especially the elongation at break and the impact strength have declined significantly. This may be due to excessive oxidation caused by excessive concentration of hydrogen peroxide, which in turn leads to surface embrittlement and breakage of the matrix molecular chain. The results of Comparative Example 4 show that the slight decline in mechanical properties may be due to the fact that the high shear and large flux of the main material simultaneously lead to residual agglomeration of the modified SiO2 and insufficient reaction of the epoxy grafted ABS.

[0088] Weathering test: The ABS composite material samples prepared in Example 3 and Comparative Examples 1 to 4 and the control group (ABS matrix material) were subjected to UV lamp aging test. The test parameters were UVA-340 lamp tube simulating ultraviolet rays (0.55 W / m 2 ), light: temperature 60℃, humidity 75%, for 8h; condensation: 50℃, humidity 100%, for 4h; dark 12h, test 1000h, test impact strength retention rate (%) = impact strength after test / impact strength before test × 100%, the results are as follows Figure 1 At the same time, the glossiness was measured every 200 hours using a multi-angle gloss meter (60°), and the gloss retention rate (%) was calculated as: gloss after test / gloss before test × 100%. Three parallel tests were performed for each test, and the average value was taken. The results are shown in the figure below. Figure 2 shown.

[0089] Depend on Figure 1 and Figure 2The results show that, compared with the pure ABS material in the control group, the ABS composite material prepared in the embodiment of the present invention has an impact strength retention rate of more than 90% and a gloss retention rate of more than 90% in a UV lamp test of up to 1000 hours, and has excellent weather resistance; from the results of Comparative Example 1, it can be seen that the impact strength and glossiness are significantly reduced compared with Example 3, among which the overall decline in gloss retention rate is linear, which may be due to the lack of the epoxy grafting layer. The SiO2 particles are only adsorbed by van der Waals forces, and water molecules penetrate into the interface during the wet-heat cycle, resulting in plasticization. The particles agglomerate into micron-sized aggregates, and microcracks expand along the aggregates under thermal stress, ultimately resulting in a significant decrease in impact strength and gloss performance. From the results of Comparative Example 2, it can be seen that the impact strength and glossiness are significantly reduced compared with Example 3, among which the gloss retention rate decreases significantly within 400 hours, and the gloss retention rate decreases slowly after 400 hours. This may be because the SiO2 nanoparticles are not aminopropylated, and the hydrophilic groups (Si-OH) on the surface of the particles trigger interfacial hydrolysis. During the long-term illumination-condensation cycle, there is a difference in volume expansion, which causes the particles to be pulled out to form micropores. The micropores become the source of cracks, and the decay slows down slightly after the surface micropores are saturated under long-term action. From the results of Comparative Example 3, it can be seen that the impact strength and glossiness plummet, and the performance is even worse than that of the control group. Among them, the gloss retention rate shows a collapse-like decline in 200 hours, and the decay decreases slightly in the later period. This may be because the high concentration of H2O2 attacks the double bond of butadiene to generate hydroperoxides, and Norrish occurs under UV light. Type I chain scission (α-cleavage) produces active free radicals on the surface, which leads to deep oxidation cracking, rapid performance degradation, thickening of the powdered layer to cover the bottom layer, and slightly slowing down the attenuation in the later stage, but the overall performance is still significantly inferior to the control group; from the results of Comparative Example 4, it can be seen that the impact strength and glossiness are significantly reduced compared with Example 3, among which the gloss retention rate maintains a good effect before 600h, and the decline rate accelerates after 600h, showing a segmented attenuation. This may be due to the lack of masterbatch pre-dispersion, uneven dispersion of gradient SiO2, coarse particles forming local stress concentration areas, insufficient interface bonding, and impact degradation after non-uniform aging. At the same time, local corrosion pits cause delayed gloss attenuation.

[0090] Water vapor transmission rate test: The ABS composite material samples prepared in Example 3 and Comparative Examples 1 to 4 and the control group (ABS matrix material) were prepared into 2 mm thick and 100 mm diameter discs, vacuum dried at 50°C for 48 hours, and equilibrated in a constant temperature and humidity chamber at 23°C / 50% humidity for 24 hours for pretreatment. Then, the water vapor transmission rate was measured at 38°C and 90% humidity according to standard ASTM E96. Each test was conducted in triplicate. Three points were selected for testing on each test sample (center + two points on the edge), and the results were averaged. The results are shown in the figure. Figure 3 shown.

[0091] Depend on Figure 3The results show that the ABS composite material prepared by the present invention effectively blocks the path of water molecules based on the double covalent anchoring effect, thereby avoiding the performance degradation caused by the invasion of water molecules; the results of Comparative Example 1 show that the water vapor transmission rate is significantly increased compared with the embodiment, which may be due to the lack of epoxy-amine covalent bonds. Although SiO2 still carries -NH2, it can only be adsorbed by van der Waals forces; the wet heat cycle promotes interfacial hydrolysis and plasticization, and micropores are left after the particles agglomerate, forming straight-through channels, which affects the barrier performance; the results of Comparative Example 2 show that the water vapor transmission rate is significantly increased compared with the embodiment, which may be due to the lack of aminopropylation, the small difference in polarity between the Si-OH layer on the particle surface and the matrix, and the hydrophilic SiO2 adsorbs water and the interfacial hydrolysis expands the channel. The barrier performance is significantly reduced. From the results of Comparative Example 3, it can be seen that the water vapor permeability soars, which is significantly higher than that of the control group. This may be because the high concentration of H2O2 causes excessive oxidation of the butadiene chain, resulting in a large amount of -OH / -COOH generated on the surface, a significant increase in polar groups, and the resin phase absorbs water and expands. Oxidation produces local segment shrinkage and microcracks, and at the same time causes the SiO2-matrix interface to be oxidized and weakened. The double superposition of hydrophilic water absorption and microcrack short-circuiting leads to performance inferior to that of the control group. From the results of Comparative Example 4, it can be seen that the water vapor permeability is significantly increased compared with the embodiment. This may be because SiO2 and epoxy-grafted ABS are added to the main material and extruded at the same time, forming an uneven distribution of fine particle areas and coarse agglomerate areas, which may result in obvious local water vapor permeability.

[0092] Spectrum test: Take the epoxy grafted ABS prepared in Example 3 and perform FTIR infrared spectrum test. The results are as follows: Figure 4 Take the ABS composite material samples of Example 3 and Comparative Example 3 after weather resistance test and perform SEM scanning electron microscopy test. The results are as shown. Figure 5 and Figure 6 shown.

[0093] Depend on Figure 4 The results show that compared with pure ABS, the FTIR spectrum of grafted ABS is 910-950cm -1 There is an obvious epoxy group COC symmetrical stretching peak in the region, 1220-1250cm -1 The area shows an enhanced shoulder peak at 1710-1730cm -1 The enhanced peak appears in the region, and the epoxy grafting is successfully achieved; it can be clearly seen from the SEM surface morphology after 1000h aging that Figure 5 The ABS composite material of the embodiment still maintains a continuous and dense surface structure, with only a small number of nano-scale holes; there are no through cracks or severe peeling; in contrast, Figure 6 The ABS composite material of Comparative Example 3 had large-area holes, cracks and flaky peeling, and its surface integrity was significantly reduced.

[0094] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A highly weather-resistant ABS composite material, characterized in that: The composition comprises the following components by weight: 90-100 parts of ABS matrix, 1.2-1.5 parts of aminopropylated nano-SiO2, 2-3 parts of waterborne polyurethane, 1.2-1.8 parts of acrylic emulsion, 0.25-0.35 parts of polyethylene wax, 0.2-0.25 parts of antioxidant and 0.7-0.8 parts of UV absorber; The ABS matrix is ​​composed of 95-97 wt% ABS and 3-5 wt% epoxy grafted ABS; The preparation steps of the epoxy grafted ABS are as follows: S1: ABS is vacuum dried to obtain dry ABS; glycidyl methacrylate is placed in a sealed drying container and impurities are removed using a filter membrane; dry ABS, peroxide, AO-1010 and dodecanethiol are premixed to obtain ABS material; S2: The ABS material from step S1 is fed into a twin-screw extruder. After stabilization, vacuum is applied, and glycidyl methacrylate, which has been cleaned from step S1, is continuously injected from the side feed port of Zone 2. The temperature is continuously raised and maintained, and glycidyl methacrylate is grafted with the main chain free radicals in Zone 2-3. Mixing is performed in Zone 4. Vacuum degassing is performed in Zone 5, followed by extrusion, cooling in a water tank, drying, and vacuum drying to obtain epoxy-grafted ABS. The preparation of the highly weather-resistant ABS composite material comprises the following steps: S201: vacuum drying the ABS substrate to obtain pretreated ABS and pretreated epoxy grafted ABS, and drying the aminopropylated nano-SiO2 to obtain pretreated aminopropylated nano-SiO2; S202: The pretreated epoxy-grafted ABS and pretreated aminopropylated nano-SiO2 prepared in step S201 are premixed and dispersed uniformly in a high-speed mixer, and then added to a twin-screw extruder to prepare SiO2 masterbatch; S203: Raise the temperature to 180-190°C, add the pretreated ABS from step S201, polyethylene wax, antioxidant, and UV absorber into a twin-screw extruder, add the SiO2 masterbatch from step S202 into the side feeder, blend, vacuum degas, extrude, cool in a water tank, blow dry, and vacuum dehumidify at room temperature to obtain ABS material; S204: adding the ABS material from step S203 into the barrel for injection molding and naturally cooling; S205: After completing the treatment in step S204, the substrate is impregnated with an APTES solution and dried; then coated with an aqueous polyurethane-acrylic acid composite solution and dried in stages to obtain an ABS composite material; In step S205 , the APTES solution is prepared by adding 3-aminopropyltriethoxysilane to an 80 wt % ethanol solution and adding 1% by mass of hydrogen peroxide.

2. The highly weather-resistant ABS composite material according to claim 1, characterized in that: In step S1, the peroxidant is any one of di-tert-butyl peroxide and dicumyl peroxide; in step S1, the mass ratio of the dried ABS, peroxidant, AO-1010 and dodecanethiol is 1:0.005-0.007:0.001:0.003-0.004; in step S2, the mass ratio of the ABS material and glycidyl methacrylate is 1:0.06-0.

08.

3. The highly weather-resistant ABS composite material according to claim 1, characterized in that: The preparation steps of the aminopropylated nano-SiO2 are as follows: S101: Add SiO2 to an ethanol solution, disperse it evenly through ultrasonic treatment, add glacial acetic acid dropwise to adjust the pH, and slowly add 3-aminopropyltriethoxysilane dropwise under nitrogen protection. After the addition is complete, heat the solution and stir. S102: After completing step S101, the temperature is raised, refluxed, and continuously purged with nitrogen. The mixture is centrifuged and repeatedly washed with anhydrous ethanol and an ethanol solution, and vacuum dried to obtain nano-aminopropylated SiO2. In step S101, the ratio of the amount of SiO2 to the ethanol solution is 1 g:15-20 mL; the ratio of the amount of SiO2 to 3-aminopropyltriethoxysilane is 1 g:0.6-0.7 mL.

4. The highly weather-resistant ABS composite material according to claim 1, characterized in that: The antioxidant is composed of AO-1010 and AO-168 in a mass ratio of 1:

2.

5. The highly weather-resistant ABS composite material according to claim 1, characterized in that: The UV absorber is any one of UV531 and HALS-770.

6. The highly weather-resistant ABS composite material according to claim 1, characterized in that: In step S205, the aqueous polyurethane-acrylic acid composite solution is prepared by uniformly mixing aqueous polyurethane, acrylic acid emulsion and the remaining weight portion of aminopropylated nano-SiO2 by ultrasonic dispersion, and adjusting the solid content to 35wt% by deionized water.

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