A PVC / SBS / nitrile rubber modified material and preparation method thereof

Abstract

The present invention discloses a PVC / SBS / nitrile rubber modified material and a preparation method thereof, belonging to the field of polymer material technology. The PVC / SBS / nitrile rubber modified material comprises the following raw materials in parts by weight: PVC: 70-90 parts, nitrile rubber: 30-40 parts, plasticizer: 5-15 parts, modified SBS: 5-15 parts, stabilizer: 2-5 parts, lubricant: 3-5 parts; the plasticizer is obtained by reacting 1,3,5-trihydroxybenzene with dihydro-4-propyl-2(3H)-furanone to obtain a polyester compound, which is then reacted with lauryl polyether-5-carboxylic acid. The PVC / SBS / nitrile rubber modified material prepared by the present invention has good mechanical properties and oil resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a PVC / SBS / nitrile rubber modified material and a preparation method thereof. Background Art

[0002] As industrial demands for material performance continue to rise, polyvinyl chloride (PVC) is widely used in automotive parts, wire and cable, and sealing products due to its low cost, excellent processing properties, and chemical resistance. However, traditional PVC materials suffer from insufficient oil resistance and poor elasticity. They are particularly susceptible to swelling, deformation, and embrittlement under long-term contact with oil media or dynamic stress environments, severely limiting their application in high-end industrial applications.

[0003] Chinese invention patent publication number CN113549287A discloses a cold-resistant and oil-resistant PVC composite elastomer cable material and its preparation method. This invention utilizes 90-100 parts PVC resin powder, 40-50 parts EBA, 20-30 parts plasticizer, 10-15 parts NBR, 5-10 parts calcium-zinc stabilizer, 0.5-3 parts lubricant, 1-3 parts processing aid, 0.5-2 parts antioxidant, and 15-20 parts calcium carbonate. The result is a product with excellent low-temperature impact resistance and tensile elongation, but poor oil resistance. Therefore, developing a PVC modified material with excellent oil resistance is of great significance in practical applications. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention aims to provide a PVC / SBS / nitrile rubber modified material and a preparation method thereof.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A PVC / SBS / nitrile rubber modified material comprises the following raw materials in parts by weight:

[0007] PVC: 70-90 parts, nitrile rubber: 30-40 parts, plasticizer: 5-15 parts, modified SBS: 5-15 parts, stabilizer: 2-5 parts, lubricant: 3-5 parts;

[0008] The plasticizer is prepared by reacting 1,3,5-trihydroxybenzene with dihydro-4-propyl-2(3H)-furanone to obtain a polyester compound, which is then reacted with laureth-5 carboxylic acid.

[0009] The plasticizer is prepared by the following method:

[0010] S1: 1,3,5-trihydroxybenzene and dihydro-4-propyl-2(3H)-furanone react with stannous octoate to form a polyester compound; the reaction equation is as follows:

[0011] .

[0012] S2: The polyester compound and laureth-5 carboxylic acid generate a plasticizer under the action of p-toluenesulfonic acid; the reaction equation is as follows:

[0013] .

[0014] The mass ratio of 1,3,5-trihydroxybenzene to dihydro-4-propyl-2(3H)-furanone in step S1 is 1:(10-15).

[0015] The mass ratio of the polyester compound to laureth-5 carboxylic acid in step S2 is 8:(10-12).

[0016] The modified SBS is prepared by the following method:

[0017] N1: SBS and maleic anhydride undergo free radical polymerization under the action of initiator benzoyl peroxide to produce maleic anhydride-grafted SBS;

[0018] N2: 2,2-dithiodiethanol reacts with hexamethylene diisocyanate in the presence of a catalyst, dibutyltin dilaurate, to form a disulfide polymer. By increasing the amount of 2,2-dithiodiethanol, a polymer with a hydroxyl terminal is generated. The reaction equation is as follows:

[0019] .

[0020] N3: The terminal hydroxyl groups in the disulfide polymer undergo esterification reaction with the anhydride in the SBS grafted with maleic anhydride to obtain modified SBS.

[0021] 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.

[0022] The lubricant is one of stearic acid ethylene diamide and calcium stearate.

[0023] A method for preparing a PVC / SBS / nitrile rubber modified material comprises the following steps:

[0024] (1) Weigh by weight: PVC: 70-90 parts, nitrile rubber: 30-40 parts, plasticizer: 5-15 parts, modified SBS: 5-15 parts, stabilizer: 2-5 parts, lubricant: 3-5 parts;

[0025] (2) The above components are added into a high-speed mixer and mixed, and then the mixture is introduced into a twin-screw extruder for extrusion and granulation, and air-cooled and sieved to obtain PVC / SBS / nitrile rubber modified material.

[0026] Due to the adoption of the above technical solution, the beneficial effects of the present invention include:

[0027] (1) The plasticizer prepared by the present invention reduces the migration of molecular chains, reduces the free volume, increases the interaction between materials, and reduces the penetration of oil molecules, thereby achieving the purpose of improving oil resistance.

[0028] (2) The modified SBS prepared in the present invention improves the tensile strength and elongation at break of the material through physical entanglement and interaction of polar groups, so that the material has good mechanical properties. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0030] Example 1 Preparation of plasticizer:

[0031] S1: Under nitrogen protection, 800g DMF, 10g 1,3,5-trihydroxybenzene and 100g dihydro-4-propyl-2(3H)-furanone were added to a reactor in sequence, stirred and mixed, heated to 100°C, stirred for 15 minutes, 5g of catalyst stannous octoate was added, reacted for 15 hours, cooled to room temperature, and distilled under reduced pressure at 60°C for 2 hours to obtain a crude product. The crude product was added to 600ml chloroform and dissolved, and then 800ml of cold methanol was added and stirred to precipitate. The precipitate was then washed three times with methanol (200ml each time) and dried in vacuo at 60°C for 5 hours to obtain a polyester compound;

[0032] S2: 800 g of toluene, 80 g of polyester compound, 100 g of lauryl polyether-5 carboxylic acid, and 6 g of p-toluenesulfonic acid were placed in a reactor in sequence, stirred and mixed, heated to 100 ° C, reacted for 10 h (the water generated during the reaction was removed by a water separator), cooled to room temperature, washed with 500 mL of saturated NaHCO3 solution and 500 ml of saturated brine in sequence, and rotary evaporated at 60 ° C for 2 h to obtain a plasticizer.

[0033] Example 2 Preparation of plasticizer:

[0034] S1: Under nitrogen protection, 800g DMF, 10g 1,3,5-trihydroxybenzene and 140g dihydro-4-propyl-2(3H)-furanone were added to a reactor in sequence, stirred and mixed, heated to 105°C, stirred for 15 minutes, 5g of stannous octoate catalyst was added, reacted for 14 hours, cooled to room temperature, and distilled under reduced pressure at 60°C for 2 hours to obtain a crude product. The crude product was added to 600ml chloroform and dissolved, and then 800ml of cold methanol was added and stirred to precipitate. The precipitate was then washed three times with methanol (200ml each time) and dried in vacuo at 60°C for 5 hours to obtain a polyester compound;

[0035] S2: 800g of toluene, 80g of polyester compound, 110g of laureth-5 carboxylic acid and 6g of p-toluenesulfonic acid were placed in a reactor in sequence, stirred and mixed, heated to 110°C, reacted for 8h (the generated water was removed by a water separator during the reaction), cooled to room temperature, washed with 500ml of saturated NaHCO3 solution and 500ml of saturated brine in sequence, and rotary evaporated at 60°C for 2h to obtain a plasticizer.

[0036] Example 3 Preparation of plasticizer:

[0037] S1: Under nitrogen protection, 800g DMF, 10g 1,3,5-trihydroxybenzene and 150g dihydro-4-propyl-2(3H)-furanone were added to a reactor in sequence, stirred and mixed, heated to 120°C, stirred for 15min, 5g stannous octoate catalyst was added, reacted for 12h, cooled to room temperature, and distilled under reduced pressure at 60°C for 2h to obtain a crude product. The crude product was dissolved in 600ml chloroform, and then 800ml cold methanol was added and stirred to precipitate. The precipitate was then washed three times with methanol (200ml each time) and dried in vacuo at 60°C for 5h to obtain a polyester compound;

[0038] S2: 800 g of toluene, 80 g of polyester compound, 120 g of laureth-5 carboxylic acid, and 6 g of p-toluenesulfonic acid were placed in a reactor in sequence, stirred and mixed, heated to 110°C, reacted for 6 h (the water generated was removed by a water separator during the reaction), cooled to room temperature, washed with 500 ml of saturated NaHCO3 solution and 500 ml of saturated brine in sequence, and rotary evaporated at 60°C for 2 h to obtain a plasticizer.

[0039] Example 4 Preparation of modified SBS:

[0040] N1: Add 100 g of trichloroethane and 300 g of butanone into a reactor, stir and mix, heat to 80°C, add 50 g of SBS, 2 g of maleic anhydride, and 0.5 g of benzoyl peroxide in sequence, react for 1 h, cool to room temperature, and distill under reduced pressure at 50°C for 3 h. Add 300 g of methanol for washing, filter, and vacuum dry at 50°C for 6 h to obtain maleic anhydride-grafted SBS;

[0041] N2: Under nitrogen protection, 200 ml of DMF, 0.1 mol of hexamethylene diisocyanate, and 0.15 mol of 2,2'-dithiodiethanol were added to the reactor in sequence, stirred and mixed, and 3 g of dibutyltin dilaurate was added. The temperature was raised to 30°C and the reaction was carried out for 6 h. 100 ml of deionized water was added to precipitate the solid, which was filtered, washed with 100 ml of deionized water, and dried in vacuo at 50°C for 6 h to obtain the disulfide polymer;

[0042] N3: 400 g of acetone, 35 g of disulfide polymer, 50 g of maleic anhydride-grafted SBS, and 12 g of anhydrous sodium acetate were added to the reactor in sequence, stirred and mixed, refluxed for 12 h, cooled to room temperature, and distilled under reduced pressure at 40°C for 2 h. 500 ml of ethyl acetate was added and stirred to dissolve. The product was washed twice with deionized water (300 ml each time). The organic phase was distilled under reduced pressure at 45°C for 2 h, and vacuum dried at 70°C for 10 h to obtain modified SBS.

[0043] Example 5 Preparation of PVC / SBS / nitrile rubber modified material:

[0044] (1) Weigh 700 g of PVC, 300 g of nitrile rubber, 50 g of plasticizer (prepared in Example 1), 50 g of modified SBS (prepared in Example 4), 20 g of stabilizer (JX-181 organotin heat stabilizer), and 30 g of lubricant (stearate ethylene diamide).

[0045] (2) The above components were added to a high-speed mixer and mixed at a mixing temperature of 150°C, a mixing speed of 250 r / min, and a mixing time of 30 min. The mixture was then introduced into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder was 20 r / s, the conveying section temperature of the twin-screw extruder was 150°C, the melting section temperature was 170°C, the mixing section temperature was 180°C, and the homogenizing section temperature was 165°C. The mixture was air-cooled and sieved to obtain the PVC / SBS / nitrile rubber modified material.

[0046] Example 6 Preparation of PVC / SBS / nitrile rubber modified material:

[0047] (1) Weigh 800 g of PVC, 350 g of nitrile rubber, 100 g of plasticizer (prepared in Example 2), 100 g of modified SBS (prepared in Example 4), 40 g of stabilizer (JX-107 reverse ester tin heat stabilizer), and 40 g of lubricant (calcium stearate).

[0048] (2) The above components were added to a high-speed mixer and mixed at a mixing temperature of 160°C, a mixing speed of 250 r / min, and a mixing time of 30 min. The mixture was then introduced into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder was 20 r / s, the conveying section temperature of the twin-screw extruder was 160°C, the melting section temperature was 170°C, the mixing section temperature was 185°C, and the homogenizing section temperature was 165°C. The mixture was air-cooled and sieved to obtain the PVC / SBS / nitrile rubber modified material.

[0049] Example 7 Preparation of PVC / SBS / nitrile rubber modified material:

[0050] (1) Weigh 900 g of PVC, 400 g of nitrile rubber, 150 g of plasticizer (prepared in Example 3), 150 g of modified SBS (prepared in Example 4), 50 g of stabilizer (JT-101 antimony mercaptan heat stabilizer), and 50 g of lubricant (calcium stearate).

[0051] (2) The above components were added to a high-speed mixer and mixed at a mixing temperature of 165°C, a mixing speed of 250 r / min, and a mixing time of 30 min. The mixture was then introduced into a twin-screw extruder for extrusion granulation. The screw speed of the screw extruder was 20 r / s, the conveying section temperature of the twin-screw extruder was 165°C, the melting section temperature was 170°C, the mixing section temperature was 185°C, and the homogenizing section temperature was 170°C. The mixture was air-cooled and sieved to obtain a PVC / SBS / nitrile rubber modified material.

[0052] Comparative Example 1

[0053] The raw material composition and process of the PVC / SBS / nitrile rubber modified material are basically the same as those in Example 6, except that the plasticizer added to the components is replaced with a plasticizer of equal mass prepared by the following method:

[0054] The preparation method of the plasticizer is basically the same as that of Example 2, except that the 1,3,5-trihydroxybenzene in step S1 is replaced by an equal weight of triethanolamine.

[0055] Comparative Example 2

[0056] The raw material composition and process of the PVC / SBS / nitrile rubber modified material are basically the same as those in Example 6, except that the plasticizer added to the components is replaced with a plasticizer of equal mass prepared by the following method:

[0057] The preparation method of the plasticizer is basically the same as that of Example 2, except that the dihydro-4-propyl-2(3H)-furanone in step S1 is replaced by an equal weight of 1,4-butyrolactone.

[0058] Comparative Example 3

[0059] The raw material composition and process of the PVC / SBS / nitrile rubber modified material are basically the same as those in Example 6, except that the plasticizer added to the components is replaced with a plasticizer of equal mass prepared by the following method:

[0060] The preparation method of the plasticizer is basically the same as that of Example 2, except that the dihydro-4-propyl-2(3H)-furanone in step S1 is replaced by an equal weight of γ-dodecalactone.

[0061] Comparative Example 4

[0062] The raw material composition and process of the PVC / SBS / nitrile rubber modified material are basically the same as those in Example 6, except that the plasticizer added to the components is replaced with a plasticizer of equal mass prepared by the following method:

[0063] The preparation method of the plasticizer is basically the same as that of Example 2, except that the laureth-5 carboxylic acid in step S2 is replaced by an equal weight of heptacosanoic acid.

[0064] Comparative Example 5

[0065] The raw material composition and process of the PVC / SBS / nitrile rubber modified material are basically the same as those in Example 6, except that the modified SBS added to the components is replaced with SBS of equal mass.

[0066] Comparative Example 6

[0067] The raw material composition and process of the PVC / SBS / nitrile rubber modified material are basically the same as those in Example 6, except that the modified SBS added to the components is replaced with an equal mass of modified SBS prepared by the following method:

[0068] The preparation method of the modified SBS is basically the same as that of Example 4, except that the 2,2-dithiodiethanol in step N2 is replaced by an equal weight of 1,6-hexanediol.

[0069] Comparative Example 7

[0070] The raw material composition and process of the PVC / SBS / nitrile rubber modified material are basically the same as those in Example 6, except that the modified SBS added to the components is replaced with an equal mass of modified SBS prepared by the following method:

[0071] The preparation method of the modified SBS is basically the same as that of Example 4, except that the hexamethylene diisocyanate in step N1 is replaced by an equal weight of 2,4-toluene diisocyanate.

[0072] The brand of PVC used in Examples 5-7 and Comparative Examples 1-7 of the present application is SG-5, the brand of nitrile rubber is Nipol® 1411C, and the brand of SBS is SBS-4230.

[0073] The PVC / SBS / nitrile rubber modified materials prepared in Examples 5-7 and Comparative Examples 1-7 were subjected to tensile strength, elongation at break, oil resistance and impact tests.

[0074] The tensile strength and elongation at break were tested in accordance with GB / T 528-2009 at a tensile speed of 100 mm / min using a type 1 dumbbell specimen. The oil resistance test was conducted in accordance with GB / T 1690-2010, with the tensile properties tested after immersion in A.3 standard oil at 100°C for 7 days. The test results are shown in Table 1.

[0075] The PVC / SBS / nitrile rubber modified materials prepared in Examples 5-7 and Comparative Examples 5-7 were subjected to a destructive test. The specific method is as follows:

[0076] Use a 1.5cm×0.5cm square iron block to evenly impact the PVC / SBS / nitrile rubber modified material (every 8cm 2 Impact 1), each impact pressure is 0.35MPa, after the impact is completed, the mechanical properties are tested after 24 hours. The test results are shown in Table 1.

[0077] Table 1 Performance test data table

[0078]

[0079] It can be seen from Examples 5, 6 and 7 in Table 1 that the PVC / SBS / nitrile rubber prepared in the present invention has excellent tensile properties and oil resistance.

[0080] The benzene rings of 1,3,5-trihydroxybenzene in the plasticizer prepared in this application form physical crosslinks with those in the modified SBS through π-π stacking, effectively anchoring the plasticizer molecules and inhibiting their migration within the polymer matrix. The plasticizer's three-arm structure and the short chain branches introduced by the polyester effectively restrict molecular chain migration and movement, improving oil resistance. Furthermore, the short chain branches reduce the free volume of the molecular chains, effectively blocking oil penetration and reducing swelling. The plasticizer introduces ether bonds (-O-) via laureth-5 carboxylic acid, which interact with PVC and nitrile rubber through electrostatic or dipole-dipole interactions, strengthening intermolecular bonding and inhibiting solvent penetration. Furthermore, the hydrophilic ether bonds have low solubility in oily media, thus inhibiting the plasticizer's migration into the oil phase.

[0081] Comparative Examples 2 and 3, respectively, use plasticizers with unbranched polyester and long-branched polyester structures, and their oil resistance is poor. Unbranched plasticizers have slightly larger intermolecular spaces than short-chain branches, allowing oil molecules to diffuse through loose or interstitial areas, reducing the material's oil resistance. Long-chain branches can isolate PVC chains, resulting in lower tensile strength despite better elongation at break. Furthermore, long-chain branches are susceptible to swelling by non-polar oils.

[0082] The modified SBS prepared in the present application promotes the effective transfer of stress through the physical entanglement of disulfide polymers with PVC and nitrile rubber matrices, thereby improving the tensile strength and elongation at break of the material. The polar groups (-NHCOO-) in the modified SBS enhance compatibility with the polar groups of PVC and nitrile rubber through electrostatic or dipole-dipole interactions, thereby improving the mechanical properties of the material. The alkyl chains in the modified SBS are highly flexible and can absorb energy through segment slippage during stretching, thereby improving the elongation at break. The introduction of disulfide bonds in the modified SBS allows the material to be repaired after mechanical damage through the reversible exchange of the fracture-recovery characteristics of the disulfide bonds. The alternating existence of flexible alkyl chains and disulfide structures enables the material to have both good tensile strength and excellent self-healing properties. The rigid benzene ring used in Comparative Example 7 restricts the movement of the molecular chain, and energy dissipation mainly relies on a single mechanism of disulfide bonds, resulting in poor self-healing properties.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in this field without departing from the scope of the technical solution of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A PVC / SBS / nitrile rubber modified material, characterized in that: The composition comprises the following raw materials in parts by weight: PVC: 70-90 parts, nitrile rubber: 30-40 parts, plasticizer: 5-15 parts, modified SBS: 5-15 parts, stabilizer: 2-5 parts, lubricant: 3-5 parts; The plasticizer is prepared by reacting 1,3,5-trihydroxybenzene with dihydro-4-propyl-2(3H)-furanone to obtain a polyester compound, which is then reacted with laureth-5 carboxylic acid; The modified SBS is prepared by the following method: N1: SBS and maleic anhydride are reacted with benzoyl peroxide to form maleic anhydride-grafted SBS; N2: 2,2-dithiodiethanol reacts with hexamethylene diisocyanate to form disulfide polymer; N3: Modified SBS is obtained by reacting disulfide polymer with SBS grafted with maleic anhydride.

2. A PVC / SBS / nitrile rubber modified material according to claim 1, characterized in that: The plasticizer is prepared by the following method: S1: 1,3,5-trihydroxybenzene reacts with dihydro-4-propyl-2(3H)-furanone under the catalysis of stannous octoate to form a polyester compound; S2: The polyester compound and laureth-5 carboxylic acid generate a plasticizer under the action of p-toluenesulfonic acid.

3. A PVC / SBS / nitrile rubber modified material according to claim 2, characterized in that: The mass ratio of 1,3,5-trihydroxybenzene to dihydro-4-propyl-2(3H)-furanone in step S1 is 1:(10-15).

4. A PVC / SBS / nitrile rubber modified material according to claim 2, characterized in that: The mass ratio of the polyester compound to laureth-5 carboxylic acid in step S2 is 8:(10-12).

5. A PVC / SBS / nitrile rubber modified material according to claim 1, characterized in that: 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.

6. A PVC / SBS / nitrile rubber modified material according to claim 1, characterized in that: The lubricant is one of stearic acid ethylene diamide and calcium stearate.

7. A method for preparing the PVC / SBS / nitrile rubber modified material according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Weigh by weight: PVC: 70-90 parts, nitrile rubber: 30-40 parts, plasticizer: 5-15 parts, modified SBS: 5-15 parts, stabilizer: 2-5 parts, lubricant: 3-5 parts; (2) The above components are added into a high-speed mixer and mixed, and then the mixture is introduced into a twin-screw extruder for extrusion and granulation, and air-cooled and sieved to obtain PVC / SBS / nitrile rubber modified material.

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