Low-temperature-resistant PVC / SEBS modified material and preparation method thereof

Abstract

The invention discloses a low-temperature-resistant PVC / SEBS modified material and a preparation method thereof, and belongs to the technical field of high polymer materials. The PVC / SEBS modified material comprises the following raw materials in parts by weight: 80-100 parts of PVC, 20-40 parts of SEBS, 5-20 parts of a plasticizer, 6-10 parts of a cold-resistant agent, 2-4 parts of a flame retardant, 5-8 parts of an anti-aging agent, 2-3 parts of a stabilizer and 3-5 parts of a lubricant. The PVC / SEBS modified material prepared by the invention has excellent cold resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a low-temperature resistant PVC / SEBS modified material and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC), as a widely used general plastic, has advantages such as low cost, good processing performance, high chemical stability, and good mechanical strength, and plays a crucial role in multiple industries such as construction, packaging, and electronics. However, PVC materials have a significant defect - poor low-temperature resistance. When the temperature drops to a certain extent, PVC will gradually change from a ductile state to a brittle state, showing low-temperature brittleness. This low-temperature brittleness mainly stems from the characteristics of its molecular structure. There are a large number of polar chlorine atoms in the PVC molecular chain, and the intermolecular force is relatively strong, which restricts the movement of molecular segments. Under low-temperature conditions, the movement of chain segments becomes more difficult, resulting in a significant decrease in the internal energy dissipation ability of the material and a sharp weakening of the resistance to external force impact or deformation. Styrene-ethylene / butene-styrene block copolymer (SEBS), as a new type of thermoplastic elastomer, has good flexibility and becomes one of the ideal choices for PVC modification. However, PVC and SEBS belong to materials with different polarities, and their compatibility is poor. There are some problems when directly blending them. In a low-temperature environment, phase separation is likely to occur in the system, making the cold resistance performance of the material unable to be fully exerted, and the low-temperature impact strength and toughness of the material are limitedly improved. In addition, the addition of traditional plasticizers can improve the flexibility and processing performance of PVC, but these plasticizers may migrate at low temperatures, reducing the cold resistance performance of the material.

[0003] Chinese invention patent with the publication number CN110511506A discloses a low-volatile PVC modified material and a preparation method thereof. The low-volatile PVC modified material includes the following raw material components in parts by weight: 100 parts of PVC resin powder, 40 - 70 parts of butadiene-based thermoplastic polyurethane (PU(HTPB)), 50 - 100 parts of styrene-ethylene / butene-styrene block copolymer (SEBS), 50 - 75 parts of naphthenic oil, 12 - 20 parts of SEBS maleic anhydride graft copolymer (SEBS-g-MAH), 3 - 5 parts of calcium-zinc stabilizer, 1 - 2 parts of lubricant, and 1 - 2 parts of antioxidant. The obtained low-volatile PVC modified material has excellent hardness and tensile strength, but its cold resistance performance is poor. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a low-temperature resistant PVC / SEBS modified material and a preparation method thereof.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions: A low-temperature resistant PVC / SEBS modified material, comprising raw materials in the following parts by weight: PVC: 80 - 100 parts, SEBS: 20 - 40 parts, plasticizer: 5 - 20 parts, cold-resistant agent: 6 - 10 parts, flame retardant: 2 - 4 parts, antioxidant: 5 - 8 parts, stabilizer: 2 - 3 parts, lubricant: 3 - 5 parts; The plasticizer is prepared by the following method: S1: 1,3 - bis((2,2 - dimethyl - 1,3 - dioxolan - 4 - yl)methoxy)propan - 2 - amine reacts with polypropylene glycol diglycidyl ether to form a dioxolane compound; S2: The dioxolane compound is hydrolyzed under the action of hydrochloric acid to form an octa - armed hydroxy compound; S3: The octa - armed hydroxy compound reacts with stearic acid under the action of p - toluenesulfonic acid to form a plasticizer.

[0006] In the step S1, the feeding mass ratio of 1,3 - bis((2,2 - dimethyl - 1,3 - dioxolan - 4 - yl)methoxy)propan - 2 - amine to polypropylene glycol diglycidyl ether is (2 - 2.5):1.

[0007] In the step S2, the feeding mass ratio of the dioxolane compound to hydrochloric acid is 4:(3 - 3.5).

[0008] In the step S3, the feeding mass ratio of the octa - armed hydroxy compound to stearic acid is 1:(3 - 5).

[0009] The cold - resistant agent is prepared by the following method: A1: Pentaerythritol reacts with 3,6 - dimethyl - 1,4 - dioxane - 2,5 - dione under the catalysis of stannous octoate to form a tetra - armed star - shaped compound; A2: The tetra - armed star - shaped compound reacts with maleimide - octaethylene glycol - carboxylic acid under the action of p - toluenesulfonic acid to form a cold - resistant agent.

[0010] In the step A1, the feeding mass ratio of pentaerythritol to 3,6 - dimethyl - 1,4 - dioxane - 2,5 - dione is 1:20.

[0011] In the step A2, the feeding mass ratio of the tetra - armed star - shaped compound to maleimide - octaethylene glycol - carboxylic acid is 1:1.5.

[0012] The flame retardant is one of tributyl phosphate, tris(2-ethylhexyl) phosphate, and tris(2-chloroethyl) phosphate; the anti-aging agent is one of N-phenyl-α-naphthylamine, N-phenyl-β-naphthylamine, and N-phenyl-N'-isopropyl-p-phenylenediamine; the stabilizer is one of JX-181 organotin heat stabilizer, JX-107 reverse ester tin heat stabilizer, and JT-101 mercaptan antimonate heat stabilizer.

[0013] The lubricant is one of fatty acids, fatty acid esters, and fatty acid amides.

[0014] A preparation method of a low-temperature resistant PVC / SEBS modified material includes the following steps: (1): Weigh by parts by weight: 80-100 parts of PVC, 20-40 parts of SEBS, 5-20 parts of plasticizer, 6-10 parts of cold-resistant agent, 2-4 parts of flame retardant, 5-8 parts of anti-aging agent, 2-3 parts of stabilizer, and 3-5 parts of lubricant; (2): Add each component into a high-speed mixer for mixing, then introduce the mixture into a twin-screw extruder for extrusion granulation, and cool it with air and screen it to obtain the PVC / SEBS modified material.

[0015] Due to the above technical solutions, the beneficial effects of the present invention include: (1) In the plasticizer prepared by the present invention, the long chain of stearate enhances the low-temperature movement ability of the molecular chain, and the octabranch structure disperses stress and inhibits crack propagation. Through the synergistic effect of the octabranch structure and the long chain of stearate, the toughness of the composite material is enhanced.

[0016] (2) The cold-resistant agent prepared by the present invention disperses stress through the three-dimensional cross-linked network of the four-arm star-shaped polyester core, inhibits low-temperature brittle fracture; introduces an octaethylene glycol chain segment to enhance the low-temperature flexibility of the molecular chain; improves the impact resistance and crack resistance of the material at extremely low temperatures. Specific embodiments

[0017] The following is further illustrated with reference to embodiments, but the present invention is not limited to these embodiments.

[0018] Example 1 Preparation of plasticizer: S1: Under nitrogen protection, add 300 g of toluene, 40 g of 1,3-bis((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propan-2-amine, and 20 g of polypropylene glycol diglycidyl ether into the reactor. Stir and heat up to 80 °C, react for 6 h, cool down to 60 °C, slowly dropwise add 45 g of 48 wt% sodium hydroxide solution over 20 min. After dropping, continue to react at 60 °C for 2 h. After the reaction is completed, cool to room temperature, slowly add 1 M dilute hydrochloric acid solution until the pH value of the reaction solution is neutral; let it stand for liquid separation, separate the aqueous phase, retain the organic phase, carry out vacuum distillation at 60 °C for 3 h, then add 100 ml of saturated sodium chloride solution for washing, repeat three times, and carry out vacuum drying at 60 °C for 12 h to obtain the heterocyclic compound; the reaction equation is shown as follows: 。

[0019] S2: Add 400 g of deionized water and 80 g of the heterocyclic compound into the reactor, then add 100 g of 15 wt% dilute hydrochloric acid, stir and mix evenly, heat up to reflux and react for 2 h, then add 10 wt% sodium hydroxide solution to adjust the pH to neutral, filter, wash with 100 g of deionized water, repeat three times, and carry out vacuum drying at 60 °C for 10 h to obtain the octa-armed hydroxyl compound; the reaction equation is shown as follows: 。

[0020] S3: Under nitrogen protection, add 300 g of toluene, 20 g of the octa-armed hydroxyl compound, and 60 g of stearic acid into the reactor, heat up to 80 °C, then add 5 g of p-toluenesulfonic acid, react for 6 h (remove the generated water using a water separator during the reaction), then cool to room temperature, slowly add saturated sodium bicarbonate solution to adjust the pH to neutral, stir well for 30 min, let it stand for liquid separation, transfer the organic phase to a rotary evaporator, and carry out vacuum distillation at 60 °C for 4 h to obtain the plasticizer; the reaction equation is shown as follows: 。

[0021] Example 2 Preparation of plasticizer: S1: Under nitrogen protection, add 300 g of toluene, 45 g of 1,3-bis((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propan-2-amine, and 20 g of polypropylene glycol diglycidyl ether into the reactor. Stir and heat up to 90 °C, react for 5 h, cool down to 60 °C, slowly dropwise add 45 g of 48 wt% sodium hydroxide solution over 20 min. After dropping, continue to react at 60 °C for 1.5 h. After the reaction is completed, cool to room temperature, slowly add 1 M dilute hydrochloric acid solution until the pH value of the reaction solution is neutral; let it stand for liquid separation, separate the aqueous phase, retain the organic phase, carry out vacuum distillation at 60 °C for 3 h to obtain the heterocyclic compound.

[0022] S2: Add 400 g of deionized water and 80 g of heterocyclic compound into the reactor, then add 110 g of 15 wt% dilute hydrochloric acid, stir to mix evenly, heat up to reflux for 3 h, add 10 wt% sodium hydroxide solution to adjust the pH to neutral, filter, wash with 100 g of deionized water, repeat three times, and dry in vacuum at 60 °C for 10 h to obtain octa-armed hydroxyl compound.

[0023] S3: Under nitrogen protection, add 300 g of toluene, 20 g of octa-armed hydroxyl compound, and 80 g of stearic acid into the reactor, heat up to 90 °C, then add 5 g of p-toluenesulfonic acid, react for 5 h (remove the generated water using a water separator during the reaction), then cool to room temperature, slowly add saturated sodium bicarbonate solution to adjust the pH to neutral, stir well for 30 min, let it stand for layer separation, transfer the organic phase to a rotary evaporator, and distill under reduced pressure at 60 °C for 4 h to obtain the plasticizer.

[0024] Example 3 Preparation of plasticizer: S1: Under nitrogen protection, add 300 g of toluene, 50 g of 1,3-bis((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propan-2-amine, and 20 g of polypropylene glycol diglycidyl ether into the reactor, stir, heat up to 100 °C, react for 4 h, cool to 60 °C, slowly dropwise add 45 g of 48 wt% sodium hydroxide solution over 20 min, after dropping, continue to react at 60 °C for 1 h, after the reaction is completed, cool to room temperature, slowly add 1 M dilute hydrochloric acid solution until the pH value of the reaction solution is neutral; let it stand for layer separation, separate the aqueous phase, retain the organic phase, distill under reduced pressure at 60 °C for 3 h, then add 100 ml of saturated sodium chloride solution to wash, repeat three times, and dry in vacuum at 60 °C for 12 h to obtain the heterocyclic compound.

[0025] S2: Add 400 g of deionized water and 80 g of heterocyclic compound into the reactor, then add 120 g of 15 wt% dilute hydrochloric acid, stir to mix evenly, heat up to reflux for 4 h, add 10 wt% sodium hydroxide solution to adjust the pH to neutral, filter, wash with 100 g of deionized water, repeat three times, and dry in vacuum at 60 °C for 10 h to obtain octa-armed hydroxyl compound.

[0026] S3: Under nitrogen protection, add 300 g of toluene, 20 g of octa-armed hydroxyl compound, and 100 g of stearic acid into the reactor, heat up to 100 °C, then add 5 g of p-toluenesulfonic acid, react for 4 h (remove the generated water using a water separator during the reaction), then cool to room temperature, slowly add saturated sodium bicarbonate solution to adjust the pH to neutral, stir well for 30 min, let it stand for layer separation, transfer the organic phase to a rotary evaporator, and distill under reduced pressure at 60 °C for 4 h to obtain the plasticizer.

[0027] Example 4 Preparation of cold-resistant agent: A1: Under nitrogen protection, add 800 g of DMF, 10 g of pentaerythritol and 200 g of 3,6-dimethyl-1,4-dioxane-2,5-dione into the reactor, stir and mix evenly, heat up to 120 °C, stir for 15 min, then add 8 g of stannous octoate catalyst, after reacting for 18 h, cool down to room temperature, carry out vacuum distillation at 60 °C for 2 h to obtain the crude product. Add the crude product into 500 ml of chloroform, stir and mix evenly, then add 200 ml of cold methanol, let it stand to precipitate, and then wash it three times with methanol (150 ml each time), and dry it under vacuum at 60 °C for 5 h to obtain the four-armed star compound; the reaction equation is shown as follows: 。

[0028] A2: Under nitrogen protection, add 300 g of toluene, 20 g of four-armed star compound, 30 g of maleimide-octapolyethylene glycol-carboxylic acid into the reactor, heat up to 90 °C, then add 5 g of p-toluenesulfonic acid, after reacting for 5 h (using a water separator to remove the generated water during the reaction), cool down to room temperature, slowly add saturated sodium bicarbonate solution to adjust the pH to neutral, stir well for 30 min, let it stand for liquid separation, transfer the organic phase to a rotary evaporator, carry out vacuum distillation at 60 °C for 4 h to obtain the cold-resistant agent; the reaction equation is shown as follows: 。

[0029] Example 5 Preparation of PVC / SEBS modified material: (1): Weigh 800 g of PVC, 200 g of SEBS, 50 g of plasticizer (prepared in Example 1), 60 g of cold-resistant agent (prepared in Example 4), 20 g of flame retardant (tributyl phosphate), 50 g of antioxidant (N-phenyl-α-naphthylamine), 20 g of stabilizer (JX-181 organotin heat stabilizer), 30 g of lubricant (fatty acid); (2): Add each component into a high-speed mixer for mixing, the mixing temperature is 110 °C, the mixing speed is 200 r / min, the mixing time is 20 min, then import the mixed material into a twin-screw extruder for extrusion granulation, the screw speed of the screw extruder is 20 r / s, the temperature of the feeding section of the twin-screw extruder is 120 °C, the melting section temperature is 160 °C, the mixing section temperature is 170 °C, the homogenization section temperature is 145 °C, air-cool and sieve to obtain the PVC / SEBS modified material.

[0030] Example 6 Preparation of PVC / SEBS modified material: (1) Weigh 900 g of PVC, 300 g of SEBS, 150 g of plasticizer (prepared in Example 2), 80 g of cold-resistant agent (prepared in Example 4), 30 g of flame retardant (tris(2-ethylhexyl) phosphate), 60 g of antioxidant (N-phenyl-β-naphthylamine), 25 g of stabilizer (JX-107 reverse ester tin heat stabilizer), and 40 g of lubricant (fatty acid ester); (2) Add each component to a high-speed mixer for mixing. The mixing temperature is 120 °C, the mixing speed is 250 r / min, and the mixing time is 25 min. Then, introduce the mixed material into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder is 20 r / s. The temperature of the conveying section of the twin-screw extruder is 120 °C, the melting section temperature is 160 °C, the mixing section temperature is 170 °C, and the homogenization section temperature is 145 °C. After air-cooling and sieving, the PVC / SEBS modified material is obtained.

[0031] Preparation of the PVC / SEBS modified material in Example 7: (1) Weigh 1000 g of PVC, 400 g of SEBS, 200 g of plasticizer (prepared in Example 3), 100 g of cold-resistant agent (prepared in Example 4), 40 g of flame retardant (tris(2-chloroethyl) phosphate), 80 g of antioxidant (N-phenyl-N'-isopropyl-p-phenylenediamine), 30 g of stabilizer (JT-101 mercaptan stibium heat stabilizer), and 50 g of lubricant (fatty acid amide); (2) Add each component to a high-speed mixer for mixing. The mixing temperature is 130 °C, the mixing speed is 300 r / min, and the mixing time is 30 min. Then, introduce the mixed material into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder is 20 r / s. The temperature of the conveying section of the twin-screw extruder is 120 °C, the melting section temperature is 160 °C, the mixing section temperature is 170 °C, and the homogenization section temperature is 145 °C. After air-cooling and sieving, the PVC / SEBS modified material is obtained.

[0032] Comparative Example 1 A low-temperature-resistant PVC / SEBS modified material, the raw material composition and process are basically the same as those in Example 6, except that the plasticizer is replaced with a plasticizer prepared by the following method with the same weight: The preparation method of the plasticizer is basically the same as that in Example 2, except that 1,3-bis((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propan-2-amine in step S1 is replaced with 2,2-dimethyl-1,3-dioxolane-4-methylamine with the same weight.

[0033] Comparative Example 2 A low-temperature resistant PVC / SEBS modified material, the raw material composition and process are basically the same as those in Example 6, the difference is that the plasticizer is replaced with a plasticizer prepared by the following method in an equal weight: The preparation method of the plasticizer is basically the same as that in Example 2, the difference is that the polypropylene glycol diglycidyl ether in step S1 is replaced with 1,6-hexanediol diglycidyl ether in an equal weight.

[0034] Comparative Example 3 A low-temperature resistant PVC / SEBS modified material, the raw material composition and process are basically the same as those in Example 6, the difference is that the plasticizer is replaced with a plasticizer prepared by the following method in an equal weight: The preparation method of the plasticizer is basically the same as that in Example 2, the difference is that the stearic acid in step S3 is replaced with hexanoic acid in an equal weight.

[0035] Comparative Example 4 A low-temperature resistant PVC / SEBS modified material, the raw material composition and process are basically the same as those in Example 6, the difference is that the cold-resistant agent is replaced with a cold-resistant agent prepared by the following method in an equal weight: The preparation method of the cold-resistant agent is basically the same as that in Example 4, the difference is that the pentaerythritol in step A1 is replaced with dipentaerythritol in an equal weight.

[0036] Comparative Example 5 A low-temperature resistant PVC / SEBS modified material, the raw material composition and process are basically the same as those in Example 6, the difference is that the cold-resistant agent is replaced with a cold-resistant agent prepared by the following method in an equal weight: The preparation method of the cold-resistant agent is basically the same as that in Example 4, the difference is that the maleimide-octapolyethylene glycol-carboxylic acid in step A2 is replaced with maleimide-tetrapolyethylene glycol-carboxylic acid in an equal weight.

[0037] Comparative Example 6 A low-temperature resistant PVC / SEBS modified material, the raw material composition and process are basically the same as those in Example 6, the difference is that the cold-resistant agent is replaced with a cold-resistant agent prepared by the following method in an equal weight: The preparation method of the cold-resistant agent is basically the same as that in Example 4, the difference is that the maleimide-octapolyethylene glycol-carboxylic acid in step A2 is replaced with oleic acid in an equal weight.

[0038] The PVC grade used in the examples and comparative examples of this application is SG-5, purchased from Shanghai Chlor-Alkali Chemical Co., Ltd.; the SEBS model used is YH-503, produced by Baling Petrochemical Co., Ltd.; the molecular weight of polypropylene glycol diglycidyl ether is 300, produced by Wuhan Shuer Biotechnology Co., Ltd.

[0039] The hardness, low-temperature brittleness, and notched impact strength tests were carried out on the PVC / SEBS modified materials prepared in the examples and comparative examples.

[0040] The hardness was tested according to the standard of GB / T531.1-2008 "Rubber, vulcanized or thermoplastic - Determination of indentation hardness - Part 1: Durometer method (Shore hardness)", and a Type A durometer was used for testing; the low-temperature brittleness was tested according to GB / T15256-2014, using a Type B strip specimen, and the notched impact strength was tested according to GB / T1843-2008. The test results are shown in Table 1.

[0041] Table 1 Performance test table of PVC / SEBS modified materials

[0042] It can be seen from Examples 5, 6, and 7 in Table 1 that the PVC / SEBS modified materials prepared by the present invention have excellent cold resistance.

[0043] The plasticizer prepared by the present invention contains a large number of ester groups, which can form dipole-dipole interactions with the chlorine atoms on the PVC chain, weaken the van der Waals force and dipole force between PVC molecular chains, reduce the glass transition temperature of the material, and improve flexibility. The long-chain alkyl groups introduced by stearic acid are hydrophobic and can insert between PVC molecular chains, increase free volume, reduce chain segment entanglement, and promote chain segment movement. The branched-chain structure can provide more physical entanglement points with the PVC chain, improve the compatibility between PVC and SEBS, and reduce the migration of the plasticizer.

[0044] The cold-resistant agent prepared by the present invention has a four-armed star structure with pentaerythritol as the core. This structure can effectively disperse external stress and inhibit the rigid fracture of molecular chains at low temperatures, thereby improving the impact resistance and anti-cracking ability of the material. The high flexibility and hydrophilicity of the grafted octaethylene glycol chain can significantly reduce the glass transition temperature of the material, enhance the movement ability of molecular chains at low temperatures, and avoid brittle fracture.

[0045] In Comparative Example 2, the straight-chain alkane structure of 1,6-hexanediol (only containing two ether oxygen bonds) limits the movement of molecular chains, resulting in poor low-temperature brittleness. In Comparative Example 5, the molecular chain length of tetraethylene glycol is short, and the movement ability of molecular chains at low temperatures is limited, resulting in a decrease in the ability to resist brittle fracture.

[0046] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. However, for those of ordinary skill in the art, within the scope of the technical solution of the present invention, any equivalent changes, such as slight modifications, evolutions, and variations made using the technical content disclosed above, are equivalent embodiments of the present invention. At the same time, any equivalent changes, such as modifications, evolutions, and variations made to the above embodiments based on the substantial technology of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A low temperature resistant PVC / SEBS modified material, characterized in that: The invention comprises the following raw materials in parts by weight: PVC: 80-100 parts, SEBS: 20-40 parts, plasticizer: 5-20 parts, cold-resistant agent: 6-10 parts, flame retardant: 2-4 parts, antioxidant: 5-8 parts, stabilizer: 2-3 parts, lubricant: 3-5 parts; The plasticizer is prepared by the following method: S1: 1,3-bis((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propan-2-amine reacts with polypropylene glycol diglycidyl ether to form a heteropentane compound; S2: The heteropentyl compound is hydrolyzed under the action of hydrochloric acid to form an eight-arm hydroxy compound; S3: The eight-arm hydroxy compound reacts with stearic acid under the action of p-toluenesulfonic acid to generate a plasticizer.

2. A low temperature resistant PVC / SEBS modified material according to claim 1, characterized in that: In the step S1, the mass ratio of 1,3-bis((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)propan-2-amine to polypropylene glycol diglycidyl ether is (2-2.5):

1.

3. The low temperature resistant PVC / SEBS modified material according to claim 1, characterized in that: In the step S2, the mass ratio of the heteropentyl ring compound to the hydrochloric acid is 4:(5-6).

4. The low temperature resistant PVC / SEBS modified material according to claim 1, characterized in that: In the step S3, the feeding mass ratio of the eight-arm hydroxy compound and stearic acid is 1:(3-5).

5. The low temperature resistant PVC / SEBS modified material according to claim 1, characterized in that: The cold-resistant agent is prepared by the following method: A1: Pentaerythritol reacts with 3,6-dimethyl-1,4-dioxane-2,5-dione under the catalysis of stannous octoate to form a four-arm star compound; A2: The four-arm star-shaped compound reacts with maleimide-octaethylene glycol-carboxylic acid under the action of p-toluenesulfonic acid to generate a cold-resistant agent.

6. The low temperature resistant PVC / SEBS modified material according to claim 5, characterized in that: In the step A1, the feed mass ratio of pentaerythritol to 3,6-dimethyl-1,4-dioxane-2,5-dione is 1:

20.

7. The low temperature resistant PVC / SEBS modified material according to claim 5, characterized in that: In the step A2, the mass ratio of the four-arm star compound to maleimide-octapolyethylene glycol-carboxylic acid is 1:1.

5.

8. The low temperature resistant PVC / SEBS modified material according to claim 1, characterized in that: The flame retardant is one of tributyl phosphate, tri(2-ethylhexyl) phosphate, and tri(2-chloroethyl) phosphate; the antioxidant is one of N-phenyl-α-aniline, N-phenyl-β-naphthylamine, and N-phenyl-N'-isopropyl-p-phenylenediamine; the stabilizer is one of JX-181 organic tin heat stabilizer, JX-107 reverse ester tin heat stabilizer, and JT-101 mercaptan antimony heat stabilizer.

9. The low temperature resistant PVC / SEBS modified material according to claim 1, characterized in that: The lubricant is one of fatty acid, fatty acid ester and fatty acid amide.

10. A method for preparing a low-temperature resistant PVC / SEBS modified material according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1): Weigh by weight: PVC: 80-100 parts, SEBS: 20-40 parts, plasticizer: 5-20 parts, cold-resistant agent: 6-10 parts, flame retardant: 2-4 parts, antioxidant: 5-8 parts, stabilizer: 2-3 parts, lubricant: 3-5 parts; (2): Add all components into a high-speed mixer and mix them. Then, introduce the mixture into a twin-screw extruder for extrusion and granulation, and air-cool and sieve to obtain the PVC / SEBS modified material.

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