CN118271654A - A kind of anti-aging toughened and reinforced polyolefin plastic and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of functional polymer materials, and discloses an anti-aging toughening reinforced polyolefin plastic and a preparation method thereof. The preparation method comprises the following steps: adding hydrogen terminated silicone oil and alpha, omega-diene into an organic solvent according to the mol ratio of 1:2-2.2, heating and catalyzing the mixture to react to obtain olefin terminated modified polysiloxane; then carrying out melt blending reaction on polyolefin, olefin end-capped modified polysiloxane, vinyl MQ silicon resin and an initiator, and extruding and granulating to obtain anti-aging toughening reinforcing master batch; and then the obtained anti-aging toughening reinforcing master batch and the polyolefin base material are subjected to melt blending extrusion granulation to obtain the anti-aging toughening reinforcing polyolefin plastic. The invention can obviously improve the strength, toughness, high-temperature aging resistance and photo-aging resistance of polyolefin plastics by introducing chemical grafted long-chain polysiloxane and vinyl MQ silicon resin into the polyolefin base material.

Description

A kind of anti-aging toughened and reinforced polyolefin plastic and preparation method thereof

Technical Field

The invention belongs to the technical field of functional polymer materials, and in particular relates to an anti-aging toughened and reinforced polyolefin plastic and a preparation method thereof.

Background technique

Polyolefin (PO) materials refer to materials based on polymers obtained by polymerization or copolymerization of one or more olefins, which mainly include polyethylene (PE), polypropylene (PP), polyolefin elastomer (POE), ethylene-vinyl acetate copolymer (EVA), etc. It is a type of polymer material with the largest output and the most applications; among them, PE and PP are the most important. Due to the characteristics of abundant raw materials, low price, easy processing and molding, and excellent comprehensive performance, it is the most widely used in real life.

However, conventional polyolefin materials generally have the defects of poor high temperature resistance and weather resistance, and are prone to aging and deformation after long-term use. These defects can be reduced by modification. Patent CN 112341689 B discloses a heat-resistant polyethylene composite material, comprising the following components: polyethylene, a cross-linking agent, an antioxidant, polyethylene wax, light calcium carbonate, and hydrotalcite. The polyethylene composite material is based on polyethylene, to which a certain amount of polyethylene wax, light calcium carbonate, hydrotalcite, a cross-linking agent, and an antioxidant are added. The thermal stability of the polyethylene composite material is improved by the interaction of the components, so that it can work in an environment above 100°C for a long time. However, the addition of too high a content of inorganic materials will reduce the strength and toughness of the polyethylene material. Patent CN114933756 B discloses an aging-resistant polyethylene material, comprising the following raw materials by weight: 90-110 parts of polyethylene, 10-20 parts of maleic anhydride grafted polyethylene, and 5-10 parts of an organic-inorganic composite agent, wherein the organic-inorganic composite agent is an anti-ultraviolet metal oxide modified by a titanate-organosilicon composition. This patent mainly uses the anti-ultraviolet metal oxide modified by titanate-organic silicon composition to have better shielding and absorption effect on ultraviolet rays, thereby effectively improving the anti-ultraviolet aging performance of polyethylene. The improvement effect on the mechanical properties and thermal oxidation aging performance of polyethylene materials is limited.

In addition, polyolefin materials also have the defect of slightly poor toughness. The toughness of polyolefin materials can be improved by adding corresponding toughening agents. Commonly used toughening agents include maleic anhydride grafted polyethylene/polypropylene (PE/PP-g-MAH). However, polyolefin materials cannot form an elastomer part due to the lack of active groups that react with maleic anhydride, resulting in slightly poor toughening effect. In addition, the effect of PE/PP-g-MAH on improving the aging resistance of polyolefin materials is also very limited.

Therefore, providing a polyolefin material that can simultaneously improve mechanical properties, high temperature aging resistance and light aging performance to broaden its application scenarios and durability has significant research value and commercial value.

Summary of the invention

In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide a method for preparing an anti-aging toughened and reinforced polyolefin plastic.

Another object of the present invention is to provide an anti-aging toughened and reinforced polyolefin plastic prepared by the above method.

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

A method for preparing anti-aging toughened and reinforced polyolefin plastics, comprising the following preparation steps:

(1) adding hydrogen-terminated silicone oil and α,ω-diolefin in a molar ratio of 1:2 to 2.2 to an organic solvent and stirring to dissolve uniformly, adding chloroplatinic acid catalyst after nitrogen deoxygenation, and then heating to 70 to 90° C. and stirring to react, and after the reaction is completed, removing the solvent by reduced pressure distillation to obtain olefin-terminated modified polysiloxane (VPDMS);

(2) adding polyolefin (PO), olefin-terminated modified polysiloxane (VPDMS), vinyl MQ silicone resin (VMQ) and an initiator into an extruder for melt blending and reaction, and then extruding and granulating to obtain an anti-aging toughening and reinforcing masterbatch;

(3) adding the anti-aging toughening and reinforcing masterbatch obtained in step (2) and the polyolefin substrate into an extruder for melt blending and extrusion granulation to obtain an anti-aging toughening and reinforcing polyolefin plastic.

Preferably, the hydrogen-terminated silicone oil in step (1) is a hydrogen-terminated silicone oil with a weight average molecular weight of 1000 to 20000 and a viscosity of 10 to 600 mPa.s at 25°C.

Preferably, the α,ω＝-diolefin in step (1) is an α,ω-diolefin with a carbon number of ≥6. Such as 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, etc. The present invention uses an olefin with a carbon number of ≥6 to end-cap and modify the polysiloxane to achieve the effect of volume expansion and plasticization, which can significantly improve the compatibility of long-chain polysiloxane and polyolefin and improve the thermoplasticity of the solid product, thereby improving the grafting efficiency of the mixed reaction of long-chain polysiloxane and polyolefin materials. At the same time, the olefin-end-capped modified polysiloxane can form an elastomeric structure with the polyolefin, and finally achieve the effect of significantly improving the aging resistance and toughness.

Preferably, the organic solvent in step (1) is toluene, xylene, petroleum ether, isopropanol, butanol, etc.

Preferably, the polyolefin in step (2) is polyethylene (PE) or polypropylene (PP).

Preferably, the vinyl MQ silicone resin in step (2) is a vinyl MQ silicone resin with a molecular weight of 3000-8000 g/mol and a vinyl content of 0.5-3.0 wt%. It can be purchased commercially, and solvent-based liquid vinyl MQ silicone resin or powdered vinyl MQ silicone resin can be used, such as 5202P vinyl VMQ resin, 5202S vinyl VMQ resin, 5202N vinyl VMQ resin, etc. of Hubei Xinsihai Chemical Co., Ltd. The present invention uses vinyl MQ silicone resin as a reinforcing agent, which can significantly improve the strength of the obtained polyolefin plastic. And further, under the compatibilization effect of olefin-terminated modified polysiloxane, its reinforcing effect is more significant.

Preferably, in step (2), the mass ratio of the polyolefin, olefin-terminated modified polysiloxane and vinyl MQ silicone resin added is 100:2-10:2-10.

Preferably, the initiator in step (2) is dicumyl peroxide (DCP), benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN); the amount of the initiator added is 0.1% to 0.5% of the mass of the polyolefin.

Preferably, the temperature of the melt blending reaction in step (2) is 180 to 220° C., and the time is 15 to 90 minutes.

Preferably, the polyolefin substrate in step (3) is polyethylene (PE), polypropylene (PP), polyolefin elastomer (POE) or ethylene-vinyl acetate copolymer (EVA).

Preferably, the amount of the anti-aging toughening and reinforcing masterbatch added in step (3) is 5% to 15% of the mass of the polyolefin substrate.

An anti-aging toughened and reinforced polyolefin plastic is prepared by the method.

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

(1) The present invention prepares an anti-aging toughening and reinforcing masterbatch by grafting copolymerization of olefin-terminated modified polysiloxane with polyolefin, which can introduce chemically grafted long-chain polysiloxane into the polyolefin matrix and form an elastomeric structure, thereby significantly improving the aging resistance and toughness of polyolefin plastics.

(2) The present invention can form a cross-linked network in the polyolefin substrate by introducing vinyl MQ silicone resin and using the compatibilizing effect of olefin-terminated modified polysiloxane to achieve a reinforcing effect and significantly improve the strength of the obtained polyolefin plastic.

Detailed ways

The present invention is further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1

A method for preparing anti-aging toughened and reinforced polyolefin plastics, comprising the following preparation steps:

(1) Hydrogen-terminated silicone oil (commercially available, with an average molecular weight of 6000, a H content of 0.032%, and a viscosity of 100 mPa.s at 25°C) and 1,7-octadiene in a molar ratio of 1:2.1 were added to a toluene solvent and stirred to dissolve evenly. After nitrogen deoxygenation, a chloroplatinic acid catalyst solution was added, and then the temperature was raised to 80°C and stirred to react for 5 h. The H content was detected. After the reaction was complete, the solvent and unreacted raw materials were removed by reduced pressure distillation to obtain a light yellow viscous liquid octene-terminated modified polysiloxane (VPDMS). The alkenyl content of the product (in terms of _CH2 =CH-) was measured to be 0.92 wt.%.

(2) Low-density polyethylene (LDPE), octene-terminated modified polysiloxane (VPDMS), powdered vinyl MQ silicone resin (5202P vinyl VMQ resin, molecular weight 5150 g/mol, vinyl content 1.07 wt%) and initiator diisopropylbenzene peroxide (DCP) were added to a twin-screw extruder for melt blending reaction and extrusion granulation to obtain an anti-aging toughening and reinforcing masterbatch. The mass ratio of LDPE, VPDMS and VMQ added was 100:5:5, and the amount of DCP added was 0.4% of the mass of LDPE. The temperatures of each section from the feed port to the outlet of the twin-screw extruder were controlled to 180°C, 180°C, 190°C, 210°C, 200°C and 180°C, respectively, and the feed speed was controlled to control the melt blending reaction to 60 minutes.

(3) adding the anti-aging toughening and reinforcing masterbatch obtained in step (2) and high-density polyethylene (HDPE) into a twin-screw extruder for melt blending and extrusion granulation, wherein the amount of the anti-aging toughening and reinforcing masterbatch added is 10% of the mass of HDPE, and the temperatures of each section from the feed port to the outlet of the twin-screw extruder are respectively controlled to be 170° C., 170° C., 185° C., 200° C., 180° C. and 175° C. to obtain an anti-aging toughening and reinforced polyethylene plastic.

The tensile strength (GB/T 1040-2018), impact strength (GB/T1843-2008), heat aging resistance (GB/T 7141-2008, heat aging conditions are 135°C, 168h; then the tensile strength retention (tensile strength after aging/tensile strength before aging × 100%) and impact strength retention (impact strength after aging/impact strength before aging × 100%)) of the polyethylene plastic obtained in this example are tested, and the ultraviolet aging resistance (GB/T16422.3-2022, UVA-340 (1A type) fluorescent ultraviolet lamp, 5 exposure cycles according to the artificial accelerated climate aging conditions of method A; then the tensile strength retention and impact strength retention are tested). The polyethylene prepared by replacing VPDMS with an equal amount of maleic anhydride grafted polyethylene (PE-g-MAH) is used as a control group.

The test results show that the tensile strength of the polyethylene plastic obtained in this embodiment is 65.2MPa, and the impact strength is 77.9KJ/ ^m2 ; the tensile strength retention rate after heat aging is 93.2%, and the impact strength retention rate is 95.1%; the tensile strength retention rate after ultraviolet aging is 94.5%, and the impact strength retention rate is 92.8%. The polyethylene plastic prepared by PE-g-MAH has a tensile strength of 62.6MPa and an impact strength of 68.4KJ/ ^m2 ; the tensile strength retention rate after heat aging is 82.6%, and the impact strength retention rate is 79.8%; the tensile strength retention rate after ultraviolet aging is 81.2%, and the impact strength retention rate is 85.0%.

Example 2

A method for preparing anti-aging toughened and reinforced polyolefin plastics, comprising the following preparation steps:

(1) Hydrogen-terminated silicone oil (commercially available, with an average molecular weight of 18,000, a H content of 0.011%, and a viscosity of 500 mPa.s at 25°C) and 1,9-decadiene were added to a toluene solvent at a molar ratio of 1:2.0 and stirred to dissolve evenly. After nitrogen deoxygenation, a chloroplatinic acid catalyst solution was added, and then the temperature was raised to 90°C and stirred to react for 4 hours. The H content was detected. After the reaction was complete, the solvent and unreacted raw materials were removed by reduced pressure distillation to obtain a white solid decene-terminated modified polysiloxane (VPDMS). The alkenyl content of the product was measured to be 0.30 wt.%.

(2) Polypropylene (PP), decene-terminated modified polysiloxane (VPDMS), powdered vinyl MQ silicone resin (5202P vinyl VMQ resin, molecular weight 5150 g/mol, vinyl content 1.07 wt%) and initiator benzoyl peroxide (BPO) were added to a twin-screw extruder for melt blending reaction and extrusion granulation to obtain an anti-aging toughening and reinforcing masterbatch. The mass ratio of PP, VPDMS and VMQ added was 100:2:2, and the amount of BPO added was 0.4% of the mass of PP. The temperatures of each section from the feed port to the outlet of the twin-screw extruder were controlled to 180°C, 180°C, 190°C, 210°C, 200°C and 180°C, respectively, and the feed speed was controlled to control the melt blending reaction to 60 min.

(3) adding the anti-aging toughening and reinforcing masterbatch obtained in step (2) and polypropylene (PP) into a twin-screw extruder for melt blending and extrusion granulation, wherein the amount of the anti-aging toughening and reinforcing masterbatch added is 15% of the mass of PP, and the temperature of each section from the feed port to the outlet of the twin-screw extruder is controlled to be 170° C., 170° C., 185° C., 200° C., 180° C. and 175° C., respectively, to obtain an anti-aging toughening and reinforced polypropylene plastic.

The tensile strength of the polypropylene plastic obtained in this embodiment is 73.8MPa, and the impact strength is 60.2KJ/ ^m2 ; the tensile strength retention rate after heat aging is 92.5%, and the impact strength retention rate is 92.4%; the tensile strength retention rate after ultraviolet aging is 92.8%, and the impact strength retention rate is 90.3%. The tensile strength of the polypropylene plastic prepared by replacing VPDMS with the same amount of PP-g-MAH is 69.4MPa, and the impact strength is 48.7KJ/ ^m2 ; the tensile strength retention rate after heat aging is 81.7%, and the impact strength retention rate is 82.5%; the tensile strength retention rate after ultraviolet aging is 74.6%, and the impact strength retention rate is 69.2%.

Example 3

A method for preparing anti-aging toughened and reinforced polyolefin plastics, comprising the following preparation steps:

(1) Hydrogen-terminated silicone oil (commercially available, with an average molecular weight of 1000, a H content of 0.203%, and a viscosity of 10 mPa.s at 25°C) and 1,5-hexadiene in a molar ratio of 1:2.2 were added to a toluene solvent and stirred to dissolve evenly. After nitrogen deoxygenation, a chloroplatinic acid catalyst solution was added, and then the temperature was raised to 70°C and stirred for reaction for 6 h. The H content was detected. After the reaction was complete, the solvent and unreacted raw materials were removed by reduced pressure distillation to obtain a light yellow liquid hexene-terminated modified polysiloxane (VPDMS). The alkenyl content of the product was measured to be 4.76 wt.%.

(2) Low-density polyethylene (LDPE), hexene-terminated modified polysiloxane (VPDMS), powdered vinyl MQ silicone resin (5202P vinyl VMQ resin, molecular weight 3200 g/mol, vinyl content 1.12 wt%) and initiator diisopropylbenzene peroxide (DCP) were added to a twin-screw extruder for melt blending reaction and extrusion granulation to obtain an anti-aging toughening and reinforcing masterbatch. The mass ratio of PE, VPDMS and VMQ added was 100:10:10, and the amount of DCP added was 0.5% of the mass of LDPE. The temperatures of each section from the feed port to the outlet of the twin-screw extruder were controlled to 180°C, 180°C, 190°C, 210°C, 200°C and 180°C, respectively, and the feed speed was controlled to control the melt blending reaction to 60 min.

(3) adding the anti-aging toughening and reinforcing masterbatch obtained in step (2) and high-density polyethylene (HDPE) into a twin-screw extruder for melt blending and extrusion granulation, wherein the amount of the anti-aging toughening and reinforcing masterbatch added is 5% of the mass of HDPE, and the temperatures of each section from the feed port to the outlet of the twin-screw extruder are respectively controlled to be 170° C., 170° C., 185° C., 200° C., 180° C. and 175° C. to obtain an anti-aging toughening and reinforced polyethylene plastic.

The tensile strength of the polyethylene plastic obtained in this embodiment is 57.3MPa, the impact strength is 68.6KJ/ ^m2, the heat aging tensile strength retention rate is 96.0%, the impact strength retention rate is 96.7%; the ultraviolet aging tensile strength retention rate is 95.7%, and the impact strength retention rate is 94.2%. The polyethylene plastic prepared by replacing VPDMS with an equal amount of PE-g-MAH has a tensile strength of 53.1MPa and an impact strength of 55.3KJ/ ^m2 ; the heat aging tensile strength retention rate is 79.3%, the impact strength retention rate is 80.7%; the ultraviolet aging tensile strength retention rate is 76.9%, and the impact strength retention rate is 79.2%.

From the results of Examples 1 to 3 above, it can be seen that the present invention uses VPDMS and VMQ to chemically graft and blend polyolefin plastics, which can significantly improve the heat aging resistance and UV aging resistance of polyethylene plastics compared to PE/PP-g-MAH and VMQ modification, and at the same time, the toughness improvement effect of the material is more significant. In addition, under the volume expansion effect of VPDMS, the reinforcement effect of VMQ is more significant.

Comparative Example 1

Compared with Example 1, this comparative example does not add VMQ, but uses an equal amount of VPDMS instead (that is, the mass ratio of LDPE and VPDMS added to the anti-aging toughening and reinforcing masterbatch is 100:10), and the rest is the same.

The polyethylene plastic obtained in this example has a tensile strength of 46.5 MPa and an impact strength of 70.2 KJ/m ² ; a heat aging tensile strength retention rate of 88.5% and an impact strength retention rate of 87.8%; a UV aging tensile strength retention rate of 90.1% and an impact strength retention rate of 89.6%.

By comparing the results of this comparative example with Example 1, it can be seen that the present invention can significantly improve the mechanical strength of polyolefin materials by introducing VMQ as a reinforcing agent, and has a certain synergistic effect on improving the toughness and aging resistance of the material.

Comparative Example 2

Compared with Example 1, in this comparative example, octene-terminated modified polysiloxane (VPDMS) is added in step (3), and the specific preparation steps are as follows:

Step (1) is the same as in Example 1.

(2) Low density polyethylene (LDPE), powdered vinyl MQ silicone resin (5202P vinyl VMQ resin, molecular weight 5150 g/mol, vinyl content 1.07 wt%) and initiator diisopropylbenzene peroxide (DCP) were added to a twin-screw extruder for melt blending reaction and extrusion granulation to obtain a reinforced masterbatch. The mass ratio of LDPE and VMQ added was 100:5, and the amount of DCP added was 0.4% of the mass of LDPE. The temperature of each section from the feed port to the outlet of the twin-screw extruder was controlled to 180°C, 180°C, 190°C, 210°C, 200°C and 180°C, respectively, and the feed speed was controlled to control the melt blending reaction to 60 minutes.

(3) adding the reinforcing masterbatch obtained in step (2), the octene-terminated modified polysiloxane (VPDMS) obtained in step (1) and high-density polyethylene (HDPE) into a twin-screw extruder for melt blending and extrusion granulation, wherein the amount of VPDMS added is 5% of the mass of the reinforcing masterbatch, and the amount of the reinforcing masterbatch added is 10% of the mass of the HDPE. The temperatures of the sections from the feed port to the outlet of the twin-screw extruder are respectively controlled to be 170° C., 170° C., 185° C., 200° C., 180° C. and 175° C. to obtain a reinforced polyethylene plastic.

The polyethylene plastic obtained in this comparative example has a tensile strength of 61.7 MPa and an impact strength of 64.5 KJ/m ² ; the heat aging tensile strength retention rate is 85.1%, and the impact strength retention rate is 83.8%; the UV aging tensile strength retention rate is 84.3%, and the impact strength retention rate is 87.4%.

It can be seen from the comparison between this comparative example and Example 1 that by chemically grafting VPDMS with polyolefin materials in advance and further forming a cross-linked elastic structure, the anti-aging performance and toughness of the obtained polyolefin materials can be significantly improved. Moreover, under the volume expansion effect of VPDMS, the reinforcement effect of VMQ is more significant.

Comparative Example 3

Compared with Example 1, powdered vinyl MQ silicone resin (VMQ) is added in step (3) in this comparative example. The specific preparation steps are as follows:

Step (1) is the same as in Example 1.

(2) Low-density polyethylene (LDPE), octene-terminated modified polysiloxane (VPDMS) and initiator diisopropylbenzene peroxide (DCP) were added to a twin-screw extruder for melt blending and reaction, and then extruded and granulated to obtain an anti-aging toughening and reinforcing masterbatch. The mass ratio of LDPE and VPDMS added was 100:5, and the amount of DCP added was 0.4% of the mass of LDPE. The temperatures of each section from the feed port to the outlet of the twin-screw extruder were controlled to 180°C, 180°C, 190°C, 210°C, 200°C and 180°C, respectively, and the feed speed was controlled to control the melt blending reaction to 60 minutes.

(3) The anti-aging toughening and reinforcing masterbatch obtained in step (2) is added to a twin-screw extruder for melt blending and extrusion granulation, wherein the amount of VMQ added is 5% of the mass of the anti-aging toughening and reinforcing masterbatch, and the amount of the anti-aging toughening and reinforcing masterbatch added is 10% of the mass of HDPE. The temperatures of each section from the feed port to the outlet of the twin-screw extruder are respectively controlled to 170° C., 170° C., 185° C., 200° C., 180° C. and 175° C. to obtain a reinforced polyethylene plastic.

The polyethylene plastic obtained in this comparative example has a tensile strength of 53.8 MPa and an impact strength of 69.0 KJ/m ² ; the heat aging tensile strength retention rate is 90.6%, and the impact strength retention rate is 91.4%; the UV aging tensile strength retention rate is 92.2%, and the impact strength retention rate is 89.5%.

It can be seen from the comparison results of this comparative example and Example 1 that the reinforcement effect of VMQ can be significantly improved by chemically grafting VMQ with polyolefin materials under the compatibilization effect of VPDMS in advance.

Comparative Example 4

Compared with Example 1, this comparative example uses vinyl-terminated polydimethylsiloxane with the same vinyl content (commercially available, with an average molecular weight of 6000, a vinyl content of 0.92wt.%, and a viscosity of 100mPa.s at 25°C) to replace octene-terminated modified polysiloxane (VPDMS), and the rest is the same.

The polyethylene plastic obtained in this comparative example has a tensile strength of 62.1 MPa and an impact strength of 60.3 KJ/m ² ; the heat aging tensile strength retention rate is 84.7%, and the impact strength retention rate is 84.5%; the UV aging tensile strength retention rate is 85.6%, and the impact strength retention rate is 88.2%.

By comparing the results of this comparative example with Example 1, it can be seen that the carbon chain in the VPDMS used for grafting modification is too short, and its compatibility with polyolefins is poor. At the same time, the volume expansion effect on VMQ is also poor, resulting in a significant decrease in the mechanical properties and anti-aging properties of the obtained polyolefin material.

The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims (10)

1. A method for preparing an anti-aging toughened and reinforced polyolefin plastic, characterized in that it comprises the following preparation steps: (1) adding hydrogen-terminated silicone oil and α,ω-diolefin in a molar ratio of 1:2 to 2.2 to an organic solvent and stirring to dissolve uniformly, adding chloroplatinic acid catalyst after nitrogen deoxygenation, and then heating to 70 to 90° C. and stirring to react, and after the reaction is completed, removing the solvent by reduced pressure distillation to obtain olefin-terminated modified polysiloxane; (2) adding polyolefin, olefin-terminated modified polysiloxane, vinyl MQ silicone resin and initiator into an extruder for melt blending and reaction, and then extruding and granulating to obtain an anti-aging toughening and reinforcing masterbatch; (3) adding the anti-aging toughening and reinforcing masterbatch obtained in step (2) and the polyolefin substrate into an extruder for melt blending and extrusion granulation to obtain an anti-aging toughening and reinforcing polyolefin plastic. 2. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1 is characterized in that the terminal hydrogen silicone oil in step (1) is a terminal hydrogen silicone oil with a weight average molecular weight of 1000 to 20000 and a viscosity of 10 to 600 mPa.s at 25°C; and the α, ω-diolefin is an α, ω-diolefin with a carbon number ≥ 6. 3. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1, characterized in that the organic solvent in step (1) is one or a mixed solvent of two or more of toluene, xylene, petroleum ether, isopropanol, and butanol. 4. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1, characterized in that the polyolefin in step (2) is polyethylene or polypropylene. 5. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1, characterized in that the vinyl MQ silicone resin in step (2) is a vinyl MQ silicone resin with a molecular weight of 3000-8000 g/mol and a vinyl content of 0.5-3.0 wt%. 6. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1, characterized in that the mass ratio of the polyolefin, olefin-terminated modified polysiloxane and vinyl MQ silicone resin added in step (2) is 100:2-10:2-10. 7. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1 is characterized in that the initiator in step (2) is dicumyl peroxide, benzoyl peroxide or azobisisobutyronitrile; the amount of the initiator added is 0.1% to 0.5% of the mass of the polyolefin; the temperature of the melt blending reaction is 180 to 220° C., and the time is 15 to 90 min. 8. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1, characterized in that the polyolefin substrate in step (3) is polyethylene, polypropylene, polyolefin elastomer or ethylene-vinyl acetate copolymer. 9. The method for preparing an anti-aging toughened and reinforced polyolefin plastic according to claim 1, characterized in that the amount of the anti-aging toughened and reinforced masterbatch added in step (3) is 5% to 15% of the mass of the polyolefin substrate. 10. An anti-aging toughened and reinforced polyolefin plastic, characterized in that it is prepared by the method according to any one of claims 1 to 9.