Ultraviolet aging resistant vinyl elastomer and preparation method thereof

Abstract

The invention belongs to the technical field of polyolefin preparation, and particularly relates to an anti-ultraviolet aging vinyl elastomer and a preparation method thereof. The preparation method of the anti-ultraviolet aging vinyl elastomer comprises the following steps: mixing a polyolefin base material, an inorganic filler inclusion and a vulcanizing agent according to a weight part ratio of (50-60): (10-12): (1-2), and sequentially carrying out melt blending and pressurized vulcanization to obtain the vinyl elastomer. According to the invention, the inorganic filler is subjected to polymerization modification to obtain the inorganic filler inclusion, and then the inorganic filler inclusion and the polyolefin base material are subjected to mixed reaction, so that the prepared vinyl elastomer has good ultraviolet oxidation resistance and good mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of polyolefin preparation technology, specifically relating to a vinyl elastomer resistant to ultraviolet aging and its preparation method. Background Technology

[0002] In the field of materials research today, the innovative improvement of polymers has always been one of the core driving forces for technological development. Polyolefin elastomers, as a new generation of thermoplastic elastomer materials, offer new ideas for the modification and innovation of polymer resins due to their unique properties and broad application prospects. Polyolefin elastomers are a class of polymers with high elasticity and excellent processability, mainly polymerized from olefin monomers such as polyethylene or polypropylene. They possess rubber-like elasticity while also exhibiting the processing characteristics of plastics, thus finding wide application in various fields, including automotive, construction, medical, and electronics. Polyolefin elastomers include polyethylene (PE) elastomers and polypropylene (PP) elastomers, among others. PE elastomers are a type of PE elastomer, typically a random copolymer obtained by reacting ethylene with α-olefins (including 1-octene, 1-hexene, or 1-butene). Because the α-olefins are introduced into the polymer molecular chain in a random form, the crystalline structure of polyethylene is disrupted, giving it good elasticity (vinyl elastomers can quickly recover their shape under tension and compression, exhibiting good elasticity, suitable for applications requiring high elasticity), chemical resistance (vinyl elastomers have good resistance to various chemicals such as oils, solvents, acids, and alkalis, making them widely used in the chemical industry), and excellent processing properties (vinyl elastomers have good processing properties and can be molded through injection molding, extrusion, calendering, and other methods). However, PE elastomers prepared by this method require careful design and control of the molecular chain structure; otherwise, slow cross-linking and easy glue overflow can easily occur, thus weakening the performance of the PE elastomer. Polyolefin chains contain a large number of unstable tertiary carbon atoms. Under ultraviolet light, with relatively little energy, hydrogen atoms on these tertiary carbon atoms can be removed to form tertiary carbon free radicals. Because these free radicals are highly reactive, they can cause reactions such as chain growth or degradation, producing large amounts of hydroperoxides. These hydroperoxides decompose to produce oxidation products such as acids, alcohols, and ketones, as well as olefins, leading to chain breakage and causing polyethylene (PE), polypropylene (PP), and other materials to lose their original properties and age. Current methods for addressing the aging resistance of polyolefins include molecular structure design, the addition of inorganic fillers (such as titanium dioxide and zinc oxide, which absorb, reflect, and shield ultraviolet light), light stabilizers, and antioxidants.

[0003] Patent CN117417596A discloses a polypropylene geotextile and a soft geotextile. This invention utilizes the modified carboxylated polyacrylonitrile to modify the cyano groups in the epoxy-based POSS, which has a strong ability to absorb ultraviolet light. It can also release the absorbed energy through the relaxation process from the excited state to the ground state, thus protecting the tertiary hydrogen atoms on the polypropylene molecular chain and reducing the occurrence of molecular chain degradation, thereby playing a certain role in anti-aging. On the other hand, it uses nano-titanium dioxide and mica powder as fillers, which can not only improve the mechanical strength of polypropylene, but also absorb, reflect, refract, and scatter ultraviolet light, thereby improving the shielding effect of polypropylene geotextile against ultraviolet light and improving its anti-aging performance. Patent CN118667247A discloses a UV-resistant waterproof membrane. This invention uses linear high-density polyethylene particles, linear low-density polyethylene particles, and ethylene vinyl acetate as the main raw materials, supplemented with polyethylene octene co-elastomer toughening agent, antioxidant, and UV stabilizer. After being formulated and mixed, they are melt-extruded into sheets. The resulting sheets have high tensile strength, good elongation, soft material, strong puncture resistance, and excellent resistance to UV aging.

[0004] Inorganic fillers can not only enhance the UV aging resistance of polyolefin elastomers, but also improve their mechanical properties through their own structure. However, due to their small particle size, inorganic fillers are prone to agglomeration and have poor interfacial bonding with polymer materials, often causing a decline in the performance of polyolefin elastomers and other polymer materials during use.

[0005] Therefore, it is of great significance to modify inorganic fillers to improve the UV aging resistance of the prepared polyolefin elastomers while maintaining good mechanical properties. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention modifies inorganic fillers through polymerization to obtain inorganic filler inclusions, which are then mixed and reacted with a polyolefin substrate. This results in a vinyl elastomer with excellent UV oxidation resistance and good mechanical properties, thereby solving the technical problems mentioned in the background art. Specifically, the technical solution of this invention includes the following: One objective of this invention is to provide a method for preparing a vinyl elastomer resistant to ultraviolet aging, the method comprising the following steps: A vinyl elastomer is obtained by mixing polyolefin substrate, inorganic filler inclusion body and vulcanizing agent in a weight ratio of 50~60:10~12:1~2 and then sequentially melt blending and pressure vulcanization.

[0007] Furthermore, the polyolefin substrate is composed of polyethylene resin and ethylene propylene diene monomer (EPDM) rubber mixed in a weight ratio of 1:0.3~0.5.

[0008] Furthermore, the melt index of the polyethylene resin is 10 g / 10 min to 12 g / 10 min.

[0009] Furthermore, the grade of the EPDM rubber is EPDM3430.

[0010] Furthermore, the method for preparing the inorganic filler inclusion includes the following steps: Inorganic filler, silane coupling agent and ethanol solution are mixed in a weight ratio of 1:0.3~0.4:6~7 to obtain a dispersion. The dispersion is then heated and coupled to obtain pretreated inorganic filler. Pretreated inorganic filler, acrylate, deionized water and emulsifier are mixed in a weight ratio of 1:80~90:60~70:2~3 to form a mixture. The mixture and initiator are then reacted to obtain a polymer emulsion. The polymer emulsion was freeze-dried to obtain an inorganic filler inclusion.

[0011] Furthermore, the inorganic filler includes nano zinc oxide or nano titanium dioxide.

[0012] Furthermore, the particle size of the nano zinc oxide is 30 nm, and the particle size of the nano titanium dioxide is 50 nm.

[0013] Furthermore, the silane coupling agent includes vinyltrimethoxysilane or vinyltriethoxysilane, and the silane coupling agent needs to have unsaturated carbon-carbon double bonds for subsequent participation in the polymerization reaction.

[0014] Furthermore, the ethanol solution is composed of anhydrous ethanol and deionized water in a weight ratio of 8:1.

[0015] Furthermore, the conditions for the heating coupling include a pH of 3.5-4, a temperature of 50°C-60°C, and a coupling time of 50-70 minutes.

[0016] Furthermore, the acrylate is composed of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and lauryl acrylate in a weight ratio of 1:0.5:0.2.

[0017] Furthermore, the emulsifier is composed of sodium dodecylbenzenesulfonate and emulsifier OP-10 in a weight ratio of 1:1.

[0018] Furthermore, the initiator includes ammonium persulfate.

[0019] Furthermore, the amount of the initiator used is 0.01 times the weight of the acrylate.

[0020] Furthermore, the conditions for the reaction of the mixture and the initiator include a reaction temperature of 70°C to 75°C and a reaction time of 3 to 4 hours.

[0021] Furthermore, the vulcanizing agent is composed of dicumyl peroxide and sulfur in a weight ratio of 1:0.2.

[0022] Furthermore, the conditions for melt blending include a temperature of 190°C to 210°C and a time of 7 min to 10 min, and the conditions for pressure vulcanization include a temperature of 190°C, a pressure of 10 MPa, and a time of 15 min to 20 min.

[0023] A second objective of this invention is to provide a vinyl elastomer that resists ultraviolet aging.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention first utilizes the silanol groups on the structure of a silane coupling agent to couple oxygen-containing groups such as hydroxyl groups on the surface structure of inorganic fillers, thus pretreating and modifying the inorganic fillers to obtain pretreated inorganic fillers. Subsequently, leveraging the polymerization encapsulation effect of acrylate monomers, the pretreated inorganic fillers are polymerized and encapsulated to obtain inorganic filler inclusions. This improves the uneven encapsulation caused by poor interfacial compatibility between the inorganic filler and acrylate monomers during direct polymerization, which in turn affects the mechanical properties and UV oxidation resistance of the prepared vinyl elastomer. Furthermore, the polyacrylate structure generated by acrylate polymerization is mixed and reacted with a polyolefin substrate, improving the interfacial compatibility between the inorganic filler and the polyolefin substrate. This results in a vinyl elastomer with excellent UV oxidation resistance and good mechanical properties. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0027] Preparation Example 1: The preparation method of inorganic filler inclusions specifically includes the following steps: Ten parts by weight of 30 nm nano-zinc oxide and 60 parts by weight of ethanol solution (composed of 80 parts by weight of anhydrous ethanol and 10 parts by weight of deionized water) were weighed and added to a reactor. The mixture was then dispersed using ultrasound at 300 W for 20 min. Next, 3 parts by weight of vinyltrimethoxysilane were added to the reactor, and the mixture was stirred at 500 rpm until the vinyltrimethoxysilane dissolved and dispersed uniformly to obtain a dispersion. The pH of the dispersion was adjusted to 4 with acetic acid, the stirring speed was adjusted to 200 rpm, and the mixture was heated to 50 °C and stirred for 50 min. After the reaction, the solid particles were collected by filtration. The surface of the solid particles was first rinsed with ethanol, then rinsed with deionized water until the pH of the rinse water was neutral. Finally, the particles were dried in a vacuum drying oven at 70 °C to obtain the pretreated inorganic filler. Weigh 1 part by weight of pretreated inorganic filler, 2 parts by weight of emulsifier (the emulsifier is composed of 1 part by weight of sodium dodecylbenzenesulfonate and 1 part by weight of emulsifier OP-10), and 60 parts by weight of deionized water, mix them, and disperse them under ultrasonic power of 200W for 15 min. Then add 80 parts by weight of acrylate (the acrylate is composed of 1 part by weight of 1,6-hexanediol diacrylate, 0.5 parts by weight of trimethylolpropane triacrylate, and 0.2 parts by weight of lauryl acrylate) and stir until uniformly mixed to obtain a mixture. Add 0.8 parts by weight of ammonium persulfate to the mixture and heat to 70℃ for 3 h. After the reaction is completed, cool to room temperature, place the obtained polymer emulsion in a freeze dryer, control the vacuum degree to 10 Pa, and then freeze dry at -45℃ to obtain the inorganic filler encapsulation.

[0028] Preparation Example 2: The preparation method of inorganic filler inclusions specifically includes the following steps: Ten parts by weight of 30 nm nano-zinc oxide and 65 parts by weight of ethanol solution (composed of 80 parts by weight of anhydrous ethanol and 10 parts by weight of deionized water) were weighed and added to a reactor. The mixture was then dispersed using ultrasound at 300 W for 25 min. Next, 3.5 parts by weight of vinyltrimethoxysilane were added to the reactor, and the mixture was stirred at 500 rpm until the vinyltrimethoxysilane dissolved and dispersed uniformly to obtain a dispersion. The pH of the dispersion was adjusted to 4 with acetic acid, the stirring speed was adjusted to 200 rpm, and the mixture was heated to 55 °C and stirred for 60 min. After the reaction, the solid particles were collected by filtration. The surface of the solid particles was first rinsed with ethanol, then rinsed with deionized water until the pH of the rinse water was neutral. Finally, the particles were dried in a vacuum drying oven at 70 °C to obtain the pretreated inorganic filler. Weigh 1 part by weight of pretreated inorganic filler, 2.5 parts by weight of emulsifier (the emulsifier is composed of 1 part by weight of sodium dodecylbenzenesulfonate and 1 part by weight of emulsifier OP-10), and 65 parts by weight of deionized water, mix them, and disperse them under ultrasonic power of 200W for 15 min. Then add 85 parts by weight of acrylate (the acrylate is composed of 1 part by weight of 1,6-hexanediol diacrylate, 0.5 parts by weight of trimethylolpropane triacrylate, and 0.2 parts by weight of lauryl acrylate) and stir until uniformly mixed to obtain a mixture. Add 0.85 parts by weight of ammonium persulfate to the mixture, and then heat to 70℃ and react for 3.5 h. After the reaction is completed, cool to room temperature, place the obtained polymer emulsion in a freeze dryer, control the vacuum degree to 10 Pa, and then freeze dry at -45℃ to obtain the inorganic filler encapsulation.

[0029] Preparation Example 3: The preparation method of inorganic filler inclusions specifically includes the following steps: Ten parts by weight of 30 nm nano-titanium dioxide and 70 parts by weight of ethanol solution (composed of 80 parts by weight of anhydrous ethanol and 10 parts by weight of deionized water) were weighed and added to a reactor. The mixture was then dispersed using ultrasound at 300 W for 30 min. Next, 4 parts by weight of vinyltriethoxysilane were added to the reactor, and the mixture was stirred at 600 rpm until the vinyltriethoxysilane was uniformly dispersed to obtain a dispersion. The pH of the dispersion was adjusted to 3.5 with acetic acid, the stirring speed was adjusted to 200 rpm, and the mixture was heated to 60 °C and stirred for 70 min. After the reaction, the solid particles were collected by filtration. The surface of the solid particles was first rinsed with ethanol, then rinsed with deionized water until the pH of the rinse water was neutral. Finally, the particles were dried in a vacuum drying oven at 70 °C to obtain the pretreated inorganic filler. Weigh 1 part by weight of pretreated inorganic filler, 3 parts by weight of emulsifier (the emulsifier is composed of 1 part by weight of sodium dodecylbenzenesulfonate and 1 part by weight of emulsifier OP-10), and 70 parts by weight of deionized water, mix them, and disperse them under ultrasonic power of 200W for 15 min. Then add 90 parts by weight of acrylate (the acrylate is composed of 1 part by weight of 1,6-hexanediol diacrylate, 0.5 parts by weight of trimethylolpropane triacrylate, and 0.2 parts by weight of lauryl acrylate) and stir until uniformly mixed to obtain a mixture. Add 0.9 parts by weight of ammonium persulfate to the mixture and heat to 75℃ for 4 h. After the reaction is complete, cool to room temperature, place the obtained polymer emulsion in a freeze dryer, control the vacuum degree to 10 Pa, and then freeze dry at -45℃ to obtain the inorganic filler encapsulation.

[0030] Preparation Example 4: The preparation method of inorganic filler inclusions specifically includes the following steps: The nano-titanium dioxide with a particle size of 50 nm in Preparation Example 3 was replaced with nano-titanium dioxide with a particle size of 150 nm, and the rest of the preparation process was the same as in Preparation Example 3.

[0031] Preparation Example 5: The preparation method of inorganic filler inclusions specifically includes the following steps: In Preparation Example 3, vinyltriethoxysilane was replaced with γ-aminopropyltriethoxysilane, and the rest of the preparation process was the same as in Preparation Example 3.

[0032] Preparation Example 6: The preparation method of inorganic filler inclusions specifically includes the following steps: One part by weight of 30 nm nano-titanium dioxide, three parts by weight of emulsifier (composed of one part by weight of sodium dodecylbenzenesulfonate and one part by weight of emulsifier OP-10), and 70 parts by weight of deionized water were weighed and mixed. The mixture was then ultrasonically dispersed at 200 W for 15 min. Subsequently, 90 parts by weight of acrylate (composed of one part by weight of 1,6-hexanediol diacrylate, 0.5 parts by weight of trimethylolpropane triacrylate, and 0.2 parts by weight of lauryl acrylate) were added and stirred until homogeneous to obtain a mixture. 0.9 parts by weight of ammonium persulfate were added to the mixture, and the temperature was raised to 75 °C for 4 h. After the reaction was completed, the mixture was cooled to room temperature, and the resulting polymer emulsion was placed in a freeze dryer. The vacuum degree was then controlled at 10 Pa, and the mixture was freeze-dried at -45 °C to obtain the inorganic filler inclusions.

[0033] Preparation Example 7: The preparation method of inorganic filler inclusions specifically includes the following steps: The acrylate (composed of 1 part by weight of 1,6-hexanediol diacrylate, 0.5 parts by weight of trimethylolpropane triacrylate and 0.2 parts by weight of lauryl acrylate) in Preparation Example 3 was replaced with acrylate (composed of 0.1 parts by weight of 1,6-hexanediol diacrylate, 0.1 parts by weight of trimethylolpropane triacrylate and 1.5 parts by weight of lauryl acrylate), and the rest of the preparation process was the same as in Preparation Example 3.

[0034] Example 1: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: Polyethylene resin with a melt index of 10 g / 10 min and EPDM3430 ethylene propylene diene monomer (EPDM) rubber polyolefin substrate were dried separately in a vacuum drying oven at 60°C for 10 h to remove moisture. Then, 1 part by weight of the dried polyethylene resin and 0.3 parts by weight of the dried EPDM rubber were weighed and mixed to form the polyolefin substrate. The extruder speed was controlled at 80 r / min, and then preheated to 80°C. Subsequently, 50 parts by weight of the polyolefin substrate, 10 parts by weight of the inorganic filler inclusion obtained in Preparation Example 1, and 1 part by weight of the vulcanizing agent (composed of 1 part by weight of dicumyl peroxide and 0.2 parts by weight of sulfur) were weighed and added to the extruder for mixing. The temperature was then increased to 190°C, and melt-blended at this temperature for 7 min. After melt blending, the blend was poured into a flat vulcanizing machine. The temperature of the flat vulcanizing machine was controlled at 190°C and the pressure at 10 MPa. After pressure vulcanization for 15 min, the mixture was cooled to room temperature to obtain the vinyl elastomer.

[0035] Example 2: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: Polyethylene resin with a melt index of 10 g / 10 min and EPDM3430 EPDM rubber polyolefin substrate were dried separately in a vacuum drying oven at 60°C for 10 h to remove moisture. Then, 1 part by weight of the dried polyethylene resin and 0.4 parts by weight of the dried EPDM rubber were weighed and mixed to form the polyolefin substrate. The extruder speed was controlled at 90 r / min, and then preheated to 80°C. Subsequently, 55 parts by weight of the polyolefin substrate, 15 parts by weight of the inorganic filler inclusion obtained in Preparation Example 2, and 1.5 parts by weight of the vulcanizing agent (composed of cumene peroxide and 0.2 parts by weight of sulfur) were weighed and added to the extruder for mixing. The temperature was then increased to 200°C, and melt-blended at this temperature for 9 min. After melt blending, the blend was poured into a flat vulcanizing machine. The temperature of the flat vulcanizing machine was controlled at 190°C and the pressure at 10 MPa. After pressure vulcanization for 18 min, the mixture was cooled to room temperature to obtain the vinyl elastomer.

[0036] Example 3: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: Polyethylene resin with a melt index of 12 g / 10 min and EPDM3430 EPDM rubber polyolefin substrate were dried in a vacuum drying oven at 60°C for 10 h to remove moisture. Then, 1 part by weight of the dried polyethylene resin and 0.5 parts by weight of the dried EPDM rubber were weighed and mixed to form the polyolefin substrate. The extruder speed was controlled at 100 r / min, and then preheated to 80°C. Subsequently, 60 parts by weight of the polyolefin substrate, 20 parts by weight of the inorganic filler inclusion obtained in Preparation Example 3, and 2 parts by weight of the vulcanizing agent (composed of cumene peroxide and 0.2 parts by weight of sulfur) were weighed and added to the extruder for mixing. The temperature was then raised to 210°C, and melt-blended at this temperature for 10 min. After melt blending, the blend was poured into a flat vulcanizing machine. The temperature of the flat vulcanizing machine was controlled at 190°C and the pressure at 10 MPa. After pressure vulcanization for 20 min, the mixture was cooled to room temperature to obtain the vinyl elastomer.

[0037] Comparative Example 1: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: The inorganic filler inclusion in Example 3 was replaced with the inorganic filler inclusion obtained in Preparation Example 4, and the rest of the preparation process was the same as in Example 3.

[0038] Comparative Example 2: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: The inorganic filler inclusion in Example 3 was replaced with the inorganic filler inclusion obtained in Preparation Example 5, and the rest of the preparation process was the same as in Example 3.

[0039] Comparative Example 3: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: The inorganic filler inclusion in Example 3 was replaced with the inorganic filler inclusion obtained in Preparation Example 6, and the rest of the preparation process was the same as in Example 3.

[0040] Comparative Example 4: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: The inorganic filler inclusion in Example 3 was replaced with the inorganic filler inclusion obtained in Preparation Example 7, and the rest of the preparation process was the same as in Example 3.

[0041] Comparative Example 5: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: In Example 3, the polyethylene resin with a melt index of 12 g / 10 min was replaced with polyethylene resin with a melt index of 2 g / 10 min, and the rest of the preparation process remained the same as in Example 3.

[0042] Comparative Example 6: A method for preparing a vinyl elastomer resistant to ultraviolet aging specifically includes the following steps: In Example 3, the polyethylene resin with a melt index of 12 g / 10 min was replaced with polyethylene resin with a melt index of 20 g / 10 min, and the rest of the preparation process remained the same as in Example 3.

[0043] The vinyl elastomers obtained in Examples 1-3 and Comparative Examples 1-6 were trimmed into 20mm×4mm×1mm specimens using a punching machine. The tensile rate was then set to 100mm / min, and the tensile strength was tested using a universal testing machine. The results are shown in Table 1 below.

[0044] The vinyl elastomers obtained in Examples 1-3 and Comparative Examples 1-6 were irradiated with a UV-313 ultraviolet lamp for 100 hours, with the irradiation intensity controlled at 90 W / m². 2 The ambient temperature was controlled at 50±2℃. After UV irradiation treatment, the sample was trimmed into 20mm×4mm×1mm specimens. The tensile rate was set to 100mm / min, and then the tensile strength was tested by a universal testing machine. The results are shown in Table 2 below.

[0045] The following conclusions can be drawn from the test results in Tables 1 and 2 above: (1) As can be seen from Examples 1 to 3, the vinyl elastomer prepared by the preparation method of the present invention has good mechanical properties and UV aging resistance.

[0046] (2) Comparative Example 1 shows that the prepared vinyl elastomer has poor mechanical properties and UV aging resistance. This may be because, although the inorganic filler is pretreated and encapsulated in this system, the compatibility with the polyolefin substrate is increased by the structure of polyacrylate to improve the uniform dispersion and bonding of the inorganic filler in the vinyl elastomer, thereby improving the UV aging resistance and mechanical properties, the pretreatment and encapsulation method of the inorganic filler in this system has strict requirements on the particle size of the inorganic filler. If the particle size is too large, it may not be able to achieve good encapsulation and modification under the preparation method of this system, resulting in poor modification effect when mixed with polyolefin substrate to prepare vinyl elastomer.

[0047] (3) Comparative Example 2 shows that the prepared vinyl elastomer has poor mechanical properties and UV aging resistance. This may be because although γ-aminopropyltriethoxysilane can modify the surface of inorganic fillers through silanol groups, it does not have carbon-carbon unsaturated double bond functional groups, which means it cannot polymerize with the carbon-carbon double bonds in acrylate and cannot form an effective encapsulation, resulting in poor modification effect.

[0048] (4) Comparative Example 3 shows that the prepared vinyl elastomer has poor mechanical properties and UV aging resistance. This may be due to the cross compatibility between the inorganic filler titanium dioxide and acrylate, which leads to poor encapsulation effect when directly encapsulated by acrylate without silane coupling agent treatment, thus affecting the final modification effect.

[0049] (5) Comparative Example 4 shows that the prepared vinyl elastomer has poor mechanical properties and UV aging resistance. This may be due to the excessive amount of lauryl acrylate, a single double bond monomer, which leads to poor crosslinking density and thus affects the mixing reaction with the polyolefin substrate, resulting in poor modification effect.

[0050] (6) Comparative Examples 5 and 6 show that the mechanical properties and UV aging resistance of the prepared vinyl elastomers are poor. This may be because the melt index of polyethylene resin is too low in the preparation method of this system, resulting in poor processing fluidity. During melt blending and extrusion, the dispersion difficulty is aggravated, leading to poor modification effect. On the other hand, although the melt index is too high, it may aggravate the phase separation process, resulting in the inability to form effective interfacial bonding between different materials, thus causing the performance to decline.

[0051] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing a vinyl elastomer resistant to ultraviolet aging, characterized in that, The preparation method includes the following steps: A vinyl elastomer is obtained by mixing polyolefin substrate, inorganic filler inclusion body and vulcanizing agent in a weight ratio of 50~60:10~12:1~2 and then sequentially melt blending and pressure vulcanization.

2. The method for preparing an anti-UV aging vinyl elastomer according to claim 1, characterized in that, The polyolefin substrate is composed of polyethylene resin and EPDM rubber mixed in a weight ratio of 1:0.3~0.

5.

3. The method for preparing an anti-UV aging vinyl elastomer according to claim 1, characterized in that, The method for preparing the inorganic filler inclusion includes the following steps: Inorganic filler, silane coupling agent and ethanol solution are mixed in a weight ratio of 1:0.3~0.4:6~7 to obtain a dispersion. The dispersion is then heated and coupled to obtain pretreated inorganic filler. Pretreated inorganic filler, acrylate, deionized water and emulsifier are mixed in a weight ratio of 1:80~90:60~70:2~3 to form a mixture. The mixture and initiator are then reacted to obtain a polymer emulsion. The polymer emulsion was freeze-dried to obtain an inorganic filler inclusion.

4. The method for preparing an anti-UV aging vinyl elastomer according to claim 3, characterized in that, The inorganic filler includes nano zinc oxide or nano titanium dioxide.

5. The method for preparing an anti-UV aging vinyl elastomer according to claim 3, characterized in that, The silane coupling agent includes vinyltrimethoxysilane or vinyltriethoxysilane.

6. The method for preparing an anti-UV aging vinyl elastomer according to claim 3, characterized in that, The conditions for the heating coupling include a pH of 3.5-4, a temperature of 50-60°C, and a coupling time of 50-70 minutes.

7. The method for preparing an anti-UV aging vinyl elastomer according to claim 3, characterized in that, The acrylate is composed of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate and lauryl acrylate in a weight ratio of 1:0.5:0.

2.

8. The method for preparing an anti-UV aging vinyl elastomer according to claim 3, characterized in that, The amount of the initiator used is 0.01 times the weight of the acrylate.

9. The method for preparing an anti-UV aging vinyl elastomer according to claim 3, characterized in that, The conditions for the reaction of the mixture and the initiator include a reaction temperature of 70℃~75℃ and a reaction time of 3h~4h.

10. A vinyl elastomer resistant to ultraviolet aging, characterized in that, The vinyl elastomer is prepared by any one of the preparation methods described in claims 1 to 9.

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