阅读说明：本技术 一种低摩擦聚苯乙烯嵌段共聚物及其制备方法 (Low-friction polystyrene block copolymer and preparation method thereof ) 是由 赵书敏 于 2021-01-13 设计创作，主要内容包括：本发明公开一种低摩擦聚苯乙烯嵌段共聚物及其制备方法；该低摩擦聚苯乙烯嵌段共聚物由端羟基聚苯乙烯与RAFT链转移剂反应形成聚苯乙烯大分子链转移剂,聚苯乙烯大分子链转移剂再引发烯丙基丙二酸二甲酯聚合,得到低摩擦聚苯乙烯嵌段共聚物；本发明通过在聚苯乙烯分子链上嵌段入聚烯丙基丙二酸二甲酯,使聚苯乙烯分子链柔性增强,且在形成聚苯乙烯材料时,聚烯丙基丙二酸二甲酯在聚苯乙烯材料的表面形成保护层,使聚苯乙烯材料的耐磨性能增强。(The invention discloses a low-friction polystyrene block copolymer and a preparation method thereof; the low-friction polystyrene block copolymer is prepared by reacting hydroxyl-terminated polystyrene with an RAFT (reversible addition-fragmentation chain transfer) agent to form a polystyrene macromolecular chain transfer agent, and then initiating the polymerization of dimethyl allylmalonate by the polystyrene macromolecular chain transfer agent to obtain the low-friction polystyrene block copolymer; according to the invention, the poly-allyl dimethyl malonate is blocked on the polystyrene molecular chain, so that the flexibility of the polystyrene molecular chain is enhanced, and when the polystyrene material is formed, the poly-allyl dimethyl malonate forms a protective layer on the surface of the polystyrene material, so that the wear resistance of the polystyrene material is enhanced.)

1. A low friction polystyrene block copolymer, wherein the low friction polystyrene block copolymer has the structure of formula (I):

wherein n is 50-100, and m is 10-20.

2. The method for preparing a low friction polystyrene block copolymer according to claim 1, comprising the steps of:

(1) taking tetrahydrofuran as a solvent, and reacting 2- (ethylmercapto-thiocarbonylthio) -2-methylpropanoic acid with SOCl₂Carrying out acyl chlorination reaction, and then carrying out esterification reaction with hydroxyl-terminated polystyrene by using toluene as a solvent and pyridine as an acid-binding agent to obtain a polystyrene macromolecular chain transfer agent;

(2) and (2) taking toluene/DMF as a solvent, azodiisobutyronitrile as an initiator, a polystyrene macromolecular chain transfer agent as a chain transfer agent and an abrasion-resistant agent as monomers, reacting for 1-3 hours at 70-80 ℃ under the protection of oil bath nitrogen, and purifying to obtain the low-friction polystyrene block copolymer.

3. The method for preparing a low-friction polystyrene block copolymer according to claim 2, wherein in the step (1), the hydroxyl-terminated polystyrene, 2- (ethylmercaptothiocarbonylthio) -2-methylpropanoic acid and SOCl are mixed₂In a molar ratio of 1:10: 15.

4. The method for preparing a low-friction polystyrene block copolymer according to claim 2, wherein in step (2), the anti-wear agent has a structure as shown below:

。

5. the method for preparing a low-friction polystyrene block copolymer according to claim 2, wherein in the step (2), the molar ratio of the azobisisobutyronitrile to the polystyrene macromolecular chain transfer agent to the anti-wear agent is 1:10: 1000.

6. The method for preparing a low-friction polystyrene block copolymer according to claim 2, wherein in the step (2), the molar concentration of the anti-wear agent is 1 mol/L.

7. The method of preparing a low friction polystyrene block copolymer according to claim 2, wherein the volume ratio of toluene/DMF in the step (2) is 10: 1.

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a low-friction polystyrene block copolymer and a preparation method thereof.

Background

The polystyrene plastic has wide application, can be used in the fields of optical instruments, daily necessities and the like, and can be made into trays, soap boxes, rulers and the like. The brittleness of the polystyrene plastic is high, and the polystyrene plastic can be broken and the like when being subjected to high pressure. These significant drawbacks affect the space of use of polystyrene-based plastics, and if the fracture resistance and flexural strength can be significantly improved, the range of applications of polystyrene plastics is greatly increased.

In the polystyrene composite plastic, the addition of some conventional coupling agents, lubricants and common materials can not significantly improve the fracture resistance and the bending strength, so that some new polymer materials are still required to be continuously searched for to improve the relevant properties of the polystyrene composite plastic; based on the above, the invention provides a low-friction polystyrene block copolymer and a preparation method thereof.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a low-friction polystyrene block copolymer and a preparation method thereof.

The invention aims to provide a low-friction polystyrene block copolymer.

Another object of the present invention is to provide a method for preparing the low-friction polystyrene block copolymer.

The above purpose of the invention is realized by the following technical scheme:

a low friction polystyrene block copolymer having the structural formula (I):

wherein n is 50-100, and m is 10-20.

The reaction process and the preparation method of the low-friction polystyrene block copolymer are as follows:

1. taking tetrahydrofuran as a solvent, and reacting 2- (ethylmercapto-thiocarbonylthio) -2-methylpropanoic acid with SOCl₂Carrying out acyl chlorination reaction, and then carrying out esterification reaction with hydroxyl-terminated polystyrene by using toluene as a solvent and pyridine as an acid-binding agent to obtain the polystyrene macromolecular chain transfer agent.

Wherein the hydroxyl-terminated polystyrene, the 2- (ethylmercapto-thiocarbonylthio) -2-methylpropanoic acid and the SOCl₂In a molar ratio of 1:10: 15.

2. And (2) taking toluene/DMF as a solvent, azodiisobutyronitrile as an initiator, a polystyrene macromolecular chain transfer agent as a chain transfer agent and an abrasion-resistant agent as monomers, reacting for 1-3 hours at 70-80 ℃ under the protection of oil bath nitrogen, and purifying to obtain the low-friction polystyrene block copolymer.

Wherein the anti-wear agent has the following structure:

wherein the molar ratio of the azodiisobutyronitrile to the polystyrene macromolecular chain transfer agent to the wear-resisting agent is 1:10: 1000.

Wherein the molar concentration of the anti-wear agent is 1 mol/L.

Wherein the volume ratio of toluene to DMF is 10: 1.

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

(1) the invention provides a low-friction polystyrene block copolymer, which leads polystyrene molecules to have low friction performance by blocking a wear-resistant agent on a polystyrene molecular chain.

(2) The invention provides a low-friction polystyrene block copolymer, which solves the problems that the long-term wear resistance of a product is influenced and the dispersion uniformity of a wear-resistant agent is not easy to guarantee because the molecules of the wear-resistant agent and a polystyrene base material are only subjected to physical mixing action without chemical bonding action, the bonding acting force between the molecules of the wear-resistant agent and the polystyrene base material is weak, the components of the wear-resistant agent are lost.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of a low friction polystyrene block copolymer.

FIG. 2 is an infrared spectrum of a low friction polystyrene block copolymer.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are not intended to limit the present invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Example 1

2- (ethylmercaptothiocarbonylthio) -2-methylpropanoic acid (4.0mmol) and 20ml of anhydrous tetrahydrofuran THF were added to the reactor, and after the reaction temperature rose to 70 deg.C, SOCl was slowly added dropwise₂(6.0mmol) and after the dropwise addition reaction for 2 hours, the reaction was terminated and then SOCl was removed by distillation under reduced pressure₂And THF to give 2- (ethylmercaptothiocarbonylthio) -2-methylpropanoyl chloride.

Hydroxyl-terminated polystyrene (40mmol) was charged into a 50ml Schlenk flask, and after purging nitrogen three times, N₂Under protection, 30ml of anhydrous toluene is added into a disposable syringe, the temperature is raised to 70 ℃, 1ml of pyridine is injected after isocyanuric acid (acryloyloxyethyl) ester is completely dissolved, the mixture is stirred for 30min, then the 2- (ethylmercapto-thiocarbonylthio) -2-methylpropanoyl chloride dissolved in the toluene is dripped, the temperature is raised to 80 ℃, the reaction is continued for 2.5h, the product is cooled to room temperature, and after two times of continuous dissolution/precipitation circulation of the toluene/methanol, the product is dried to constant weight under vacuum at 45 ℃, and the polystyrene macromolecular chain transfer agent is obtained.

Example 2

Weighing polystyrene macromolecular chain transfer agent (0.1mmol), azobisisobutyronitrile (0.01mmol) and wear-resisting agent (10.0mmol), adding into a 25ml Schlenk bottle, pumping nitrogen for 3 times, and adding N₂Adding 10mL of toluene/DMF (v/v is 10:1) under protection, raising the temperature of the reactor to 70 ℃, reacting for 2 hours, putting the product into liquid nitrogen for quenching to stop the reaction, dripping the product into methanol/water for precipitating, dissolving the product in toluene, continuously dissolving and precipitating for 3 times, filtering, and performing condensation reactionWashing with methanol, and drying at 45 deg.C under vacuum to constant weight to obtain low-friction polystyrene block copolymer.

Example 3

100 parts of low-friction polystyrene block copolymer powder is added with 0.05 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, 0.05 part of tris (2.4-di-tert-butylphenyl) phosphite, 0.1 part of high-purity calcium stearate, 0.5 part of nucleating agent and 0.1 part of dicumyl peroxide, and the mixture is granulated by a twin-screw granulator with the temperature of 230 ℃ and the rotating speed of 100Hz to obtain the low-friction polystyrene material.

Example 4

80 parts of low-friction polystyrene block copolymer powder is added with 0.05 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, 0.05 part of tris (2.4-di-tert-butylphenyl) phosphite, 0.1 part of high-purity calcium stearate, 0.5 part of nucleating agent and 0.1 part of dicumyl peroxide, and the mixture is granulated by a twin-screw granulator with the temperature of 230 ℃ and the rotating speed of 100Hz to obtain the low-friction polystyrene material.

Example 5

60 parts of low-friction polystyrene block copolymer powder is added with 0.05 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, 0.05 part of tris (2.4-di-tert-butylphenyl) phosphite, 0.1 part of high-purity calcium stearate, 0.5 part of nucleating agent and 0.1 part of dicumyl peroxide, and the mixture is granulated by a twin-screw granulator with the temperature of 230 ℃ and the rotating speed of 100Hz to obtain the low-friction polystyrene material.

Comparative example 1

100 parts of low-friction polystyrene block copolymer powder is added with 0.05 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, 0.05 part of tris (2.4-di-tert-butylphenyl) phosphite, 0.1 part of high-purity calcium stearate, 0.5 part of nucleating agent and 0.1 part of dicumyl peroxide, and the mixture is granulated by a twin-screw granulator with the temperature of 230 ℃ and the rotating speed of 100Hz to obtain the low-friction polystyrene material.

Comparative example 2

80 parts of low-friction polystyrene block copolymer powder is added with 0.05 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, 0.05 part of tris (2.4-di-tert-butylphenyl) phosphite, 0.1 part of high-purity calcium stearate, 0.5 part of nucleating agent and 0.1 part of dicumyl peroxide, and the mixture is granulated by a twin-screw granulator with the temperature of 230 ℃ and the rotating speed of 100Hz to obtain the low-friction polystyrene material.

Comparative example 3

60 parts of low-friction polystyrene block copolymer powder is added with 0.05 part of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester, 0.05 part of tris (2.4-di-tert-butylphenyl) phosphite, 0.1 part of high-purity calcium stearate, 0.5 part of nucleating agent and 0.1 part of dicumyl peroxide, and the mixture is granulated by a twin-screw granulator with the temperature of 230 ℃ and the rotating speed of 100Hz to obtain the low-friction polystyrene material.

And (3) testing the wear resistance: injection moulding a sample with dimensions of 150 × 100 × 3.2mm, according to test method SAEJ 948: 2003, test conditions: grinding the wheel: CS-10, load: the abrasion and surface whitening of the material after the test were identified at 500 g/wheel for a total of 250 revolutions.

Tensile strength was determined according to standard HG/T2580-.

The bending strength is measured according to the standard GB/T12585-2001; and testing the impact strength of the simply supported beam.

The test specimens were 80 x 6 x 4mm in size and the depth of the indentations was one third of the thickness of the test specimens, according to ISO 179.

Table 1 shows the wear resistance of the low friction polystyrene block copolymer.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.