阅读说明：本技术 一种抗冲击改性聚苯乙烯及其制备方法 (Impact-resistant modified polystyrene and preparation method thereof ) 是由 赵书敏 于 2021-01-22 设计创作，主要内容包括：本发明公开一种抗冲击改性聚苯乙烯及其制备方法；该抗冲击改性聚苯乙烯按重量份的组分组成：80～100质量份聚苯乙烯嵌段共聚物,5～10质量份微孔玻璃,5～20质量份增韧剂,1～3质量份复合抗氧剂,2～5质量份润滑剂；本发明通过在聚苯乙烯分子链上嵌段丁苯橡胶,改善聚苯乙烯的脆性,此外,还在聚苯乙烯分子链上嵌段聚硅烷偶联剂,克服聚硅烷偶联剂和聚合物相容性差的问题,在聚合物材料中加入微孔玻璃,得到聚苯乙烯具有优良的隔音性能。(The invention discloses an impact-resistant modified polystyrene and a preparation method thereof; the impact-resistant modified polystyrene comprises the following components in parts by weight: 80-100 parts by mass of a polystyrene block copolymer, 5-10 parts by mass of microporous glass, 5-20 parts by mass of a toughening agent, 1-3 parts by mass of a composite antioxidant and 2-5 parts by mass of a lubricant; the invention improves the brittleness of the polystyrene by blocking the styrene-butadiene rubber on the polystyrene molecular chain, overcomes the problem of poor compatibility of the polysilane coupling agent and the polymer by blocking the polysilane coupling agent on the polystyrene molecular chain, and obtains the polystyrene with excellent sound insulation performance by adding the microporous glass into the polymer material.)

1. The impact-resistant modified polystyrene is characterized by comprising the following components in parts by weight: 80-100 parts by mass of a polystyrene block copolymer, 5-10 parts by mass of microporous glass, 5-20 parts by mass of a toughening agent, 1-3 parts by mass of a composite antioxidant and 2-5 parts by mass of a lubricant, wherein the polystyrene block copolymer has a structure shown in a formula (I):

in the formula, n is 25-50, m is 5-10, r is 50-100, and p is 25-50.

2. The impact-modified polystyrene as claimed in claim 1, wherein the polystyrene block copolymer is prepared by a process comprising the steps of:

(1) adding mercaptopropionic acid into an alkaline aqueous solution, dropwise adding carbon disulfide, reacting at room temperature for 5 hours, adding benzyl bromide, and reacting at 80 ℃ for 8 hours to obtain 3-benzyl trithiopropionic acid;

(2) firstly, 3-benzyl trithiopropionic acid and SOCl are mixed₂By acylchlorination, then in N₂Under protection, dissolving single-terminal hydroxy styrene-butadiene rubber in anhydrous toluene, heating to 75 ℃, adding 1ml of pyridine after the single-terminal hydroxy styrene-butadiene rubber is completely dissolved, stirring for a period of time, slowly dropwise adding a RAFT reagent 3-benzyl trithiopropionyl chloride dissolved in a proper amount of toluene solution, and stirring for 2 hours at 80 ℃ to obtain a styrene-butadiene rubber macromolecular chain transfer agent;

(3) tetrahydrofuran THF is used as a reaction solvent, azobisisobutyronitrile is used as an initiator, styrene is used as a monomer, a butadiene styrene rubber macromolecular chain transfer agent is used as a chain transfer agent, and the reaction is carried out in an oil bath at the temperature of 70-80 ℃ for 0.5-2 hours to obtain polystyrene block butadiene styrene rubber;

(4) tetrahydrofuran THF is used as a reaction solvent, azobisisobutyronitrile is used as an initiator, a silane coupling agent is used as a monomer, polystyrene block styrene butadiene rubber is used as a chain transfer agent, and the reaction is carried out in an oil bath at the temperature of 70-80 ℃ for 0.5-2 hours to obtain the polystyrene block copolymer.

3. The impact-modified polystyrene as claimed in claim 2, wherein in step (1), the aqueous alkaline solution is potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate; the molar ratio of the mercaptopropionic acid to the carbon disulfide to the benzyl bromide is 1:1: 1.

4. The impact-modified polystyrene as claimed in claim 2, wherein in step (2), the single-terminal hydroxy styrene-butadiene rubber is reacted with 3-benzyltrithiopropionic acid, SOCl₂In a molar ratio of 1:5: 20.

5. The impact-modified polystyrene as claimed in claim 2, wherein in step (3), the concentration of styrene in the polymerization system is 1 mol/L; the molar ratio of the azodiisobutyronitrile to the styrene-butadiene rubber macromolecular chain transfer agent to the styrene is 1:9: 1200.

6. The impact-modified polystyrene as claimed in claim 2, wherein in step (4), the silane coupling agent has the following structural formula:

7. the impact-modified polystyrene as claimed in claim 2, wherein in step (4), the concentration of said silane coupling agent in the polymerization system is 1 mol/L; the molar ratio of the azodiisobutyronitrile to the polystyrene block styrene-butadiene rubber to the silane coupling agent is 1:9: 1200.

8. The impact-modified polystyrene as claimed in claim 1, wherein the toughening agent is a styrene-butadiene-styrene block copolymer; the compound antioxidant is a compound of antioxidant 1076 and antioxidant 168; the lubricant is ethylene bisstearamide.

9. The process for preparing impact-modified polystyrene, as claimed in claim 1, comprising the steps of:

the composition comprises the following components in parts by weight: 80-100 parts by mass of polystyrene block polysilane, 5-20 parts by mass of toughening agent, 1-3 parts by mass of composite antioxidant and 2-5 parts by mass of lubricant are mixed in a high-speed mixer, the temperature is raised to 100 ℃ and 120 ℃, and the mixture is mixed for 8-12 minutes; cutting the mixed material into pieces, taking out the pieces, and conveying the pieces into forming equipment for preforming, wherein the forming pressure is 4-6MPa and the forming pressure is 15-20S, and then taking out the pieces; adding the sheet material into a preheated mold, pressurizing to 6-7MPa at the temperature of 140 ℃ and 160 ℃ on a flat vulcanizing machine, maintaining the pressure for 6-12min, decompressing, foaming and cooling to normal temperature to obtain the impact-resistant modified polystyrene.

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to impact-resistant modified polystyrene and a preparation method thereof.

Background

Polystyrene has the advantages of no toxicity, no odor, good transparency, high dimensional stability, corrosion resistance, fluidity, easy processing and forming and the like, and is widely used for high-gloss parts such as injection molding telephone sets, dust collectors, video tape shells and the like; polystyrene can be dissolved in organic solvents such as tetrahydrofuran, xylene and chloroform at normal temperature, but is not dissolved in solvents such as ethanol, methanol and isopropanol; many low-temperature products are made of polystyrene, and the polystyrene products have good low-temperature resistance but poor impact resistance and are easy to crack when deformed by external force, so that the use, storage, transportation and carrying of the polystyrene products are influenced, the production cost is improved, and the service life of the polystyrene is reduced.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides the impact-resistant modified polystyrene and the preparation method thereof, the brittleness of the polystyrene is improved by blocking styrene-butadiene rubber on a polystyrene molecular chain, in addition, a polysilane coupling agent is blocked on the polystyrene molecular chain, the problem of poor compatibility of the polysilane coupling agent and a polymer is solved, and microporous glass is added into a polymer material to obtain the polystyrene with excellent sound insulation performance.

The invention aims to provide an impact-resistant modified polystyrene.

Another object of the present invention is to provide a process for producing the above impact-modified polystyrene.

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

the preparation method of the impact-resistant modified polystyrene comprises the following steps:

the components by weight portion are as follows: 80-100 parts by mass of polystyrene block copolymer, 5-10 parts by mass of microporous glass, 5-20 parts by mass of toughening agent, 1-3 parts by mass of composite antioxidant and 2-5 parts by mass of lubricant are mixed in a high-speed mixer, the temperature is raised to 100 ℃ and 120 ℃, and the mixture is mixed for 8-12 minutes; cutting the mixed material into pieces, taking out the pieces, and conveying the pieces into forming equipment for preforming, wherein the forming pressure is 4-6MPa and the forming pressure is 15-20S, and then taking out the pieces; adding the sheet material into a preheated mold, pressurizing to 6-7MPa at the temperature of 140 ℃ and 160 ℃ on a flat vulcanizing machine, maintaining the pressure for 6-12min, decompressing, foaming and cooling to normal temperature.

The toughening agent is a styrene-butadiene-styrene block copolymer.

The compound antioxidant is a compound of an antioxidant 1076 and an antioxidant 168.

The lubricant is ethylene bisstearamide.

The structural formula of the polystyrene block copolymer is shown as the following formula (I):

in the formula, n is 25-50, m is 5-10, r is 50-100, and p is 25-50.

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

the preparation method of the polystyrene block copolymer comprises the following steps:

(1) adding mercaptopropionic acid into an alkaline aqueous solution, dropwise adding carbon disulfide, reacting at room temperature for 5 hours, adding benzyl bromide, and reacting at 80 ℃ for 8 hours to obtain 3-benzyl trithiopropionic acid.

Wherein the alkaline aqueous solution is potassium hydroxide, sodium hydroxide, potassium carbonate or sodium carbonate.

Wherein the molar ratio of the mercaptopropionic acid to the carbon disulfide to the benzyl bromide is 1:1: 1.

(2) Firstly, 3-benzyl trithiopropionic acid and SOCl are mixed₂By acylchlorination, then in N₂Under protection, dissolving single-terminal hydroxy styrene-butadiene rubber in anhydrous toluene, heating to 75 ℃, adding 1ml of pyridine after the single-terminal hydroxy styrene-butadiene rubber is completely dissolved, stirring for a period of time, slowly dropwise adding a RAFT reagent 3-benzyl trithiopropionyl chloride dissolved in a proper amount of toluene solution, and stirring for 2 hours at 80 ℃ to obtain the styrene-butadiene rubber macromolecular chain transfer agent.

Wherein the single-end hydroxy styrene-butadiene rubber, 3-benzyl trithiopropionic acid and SOCl₂In a molar ratio of 1:5: 20.

(3) Tetrahydrofuran THF is used as a reaction solvent, azobisisobutyronitrile is used as an initiator, styrene is used as a monomer, a butadiene styrene rubber macromolecular chain transfer agent is used as a chain transfer agent, and the reaction is carried out in an oil bath at the temperature of 70-80 ℃ for 0.5-2 hours to obtain the polystyrene block butadiene styrene rubber.

Wherein the concentration of the styrene in the polymerization system is 1 mol/L.

Wherein the molar ratio of the azodiisobutyronitrile to the styrene-butadiene rubber macromolecular chain transfer agent to the styrene is 1:9: 1200.

(4) Tetrahydrofuran THF is used as a reaction solvent, azobisisobutyronitrile is used as an initiator, a silane coupling agent is used as a monomer, polystyrene block styrene butadiene rubber is used as a chain transfer agent, and the reaction is carried out in an oil bath at the temperature of 70-80 ℃ for 0.5-2 hours to obtain the polystyrene block copolymer.

Wherein the structural formula of the silane coupling agent is as follows:

wherein the concentration of the silane coupling agent in a polymerization system is 1 mol/L.

Wherein the molar ratio of the azodiisobutyronitrile to the polystyrene block styrene-butadiene rubber to the silane coupling agent is 1:9: 1200.

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

the invention provides an impact-resistant modified polystyrene, which improves the brittleness of the polystyrene by blocking styrene-butadiene rubber on a polystyrene molecular chain, overcomes the problem of poor compatibility of a polysilane coupling agent and a polymer by blocking the polysilane coupling agent on the polystyrene molecular chain, and obtains the polystyrene with excellent sound insulation performance by adding microporous glass into a polymer material.

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

And (3) synthesizing 3-benzyl trithiopropionic acid.

Dropping mercaptopropionic acid (5mmoL) into an alkaline aqueous solution dissolved with KOH, then dropping carbon disulfide (5mmoL), stirring at room temperature for 5h, adding benzyl bromide (5mmoL), reacting at 80 ℃ for 8h, extracting with dichloromethane, performing rotary evaporation, and passing through a column to obtain the 3-benzyl trithiopropionic acid with the yield of 76.4%.

Example 2

And (3) synthesizing a styrene butadiene rubber macromolecular chain transfer agent.

Accurately weighing 3-benzyl trithiopropionic acid (5.0mmol), adding into a 50mL round-bottom flask with a branch opening, installing a reflux condenser tube, placing the reaction device on a heater, adding 20mL anhydrous tetrahydrofuran, heating to 70 ℃, and dropwise adding SOCl by using a disposable syringe₂(20.0mmol) and continuing the reaction for 2h after the dropwise addition is finished, cooling the product to room temperature after the reaction is finished, and removing SOCl by reduced pressure distillation₂And THF to give 3-benzyltrithiopropionyl chloride.

Accurately weighing single-terminal hydroxy styrene-butadiene rubber (1.0mmol) and adding into a 50ml Schlenk bottle, placing the Schlenk bottle on a heater, pumping nitrogen for 3 times, and then, N₂Under protection, 20ml of anhydrous toluene is added by a disposable syringe, the temperature is raised to 70 ℃, 1ml of pyridine is dripped after single-end hydroxy styrene-butadiene rubber is completely dissolved, stirring is carried out for 30min, then the 3-benzyl trithiopropionyl chloride dissolved in the toluene is dripped, the temperature is raised to 80 ℃, reaction is continued for 2.5h, after the reaction is finished, a product is cooled to room temperature, methanol is dripped to precipitate, then the product is dissolved by the toluene, after twice dissolving/precipitating cycles, filtering is carried out, methanol is continuously used for washing, and drying is carried out at the temperature of 45 ℃ under vacuum to constant weight, so that the styrene-butadiene rubber macromolecular chain transfer agent is obtained, and the yield is 76.7%.

Example 3

And (3) synthesizing polystyrene block styrene-butadiene rubber.

In a 50mL flask with a branch mouth, adding an initiator AIBN (0.01mmol), a styrene-butadiene rubber macromolecule transfer agent (0.09mmol) and styrene (12.0mmol) into the flask respectively, dissolving by using an organic solvent 12mL dioxane, carrying out three times of liquid nitrogen freezing-air extraction-unfreezing cycles, carrying out polymerization reaction in an oil bath at 75 ℃, immediately taking out a Schlenk bottle after the polymer is dissolved, putting the Schlenk bottle into liquid nitrogen for cooling after reaction for 0.5h, continuously dissolving/precipitating twice by using THF/diethyl ether, and drying at the temperature of 40 ℃ in vacuum to constant weight to obtain the polystyrene block styrene-butadiene rubber, wherein the yield is 69.5%.

Example 4

And (3) synthesis of a polystyrene block copolymer.

In a 50mL flask with a branch mouth, an initiator AIBN (0.01mmol), polystyrene block styrene-butadiene rubber (0.09mmol) and a silane coupling agent (12.0mmol) are respectively added into the flask, dissolved by an organic solvent 12mL dioxane, subjected to three cycles of liquid nitrogen freezing-air extraction-unfreezing, subjected to polymerization reaction in a 75 ℃ oil bath, reacted for 0.5h, immediately taken out of a Schlenk bottle, put into liquid nitrogen for cooling, subjected to continuous THF/ether dissolution/precipitation cycle for two times, and dried at the temperature of 40 ℃ in vacuum to constant weight to obtain the polystyrene block copolymer, wherein the yield is 73.3%.

Example 5

The components by weight portion are as follows: mixing 100 parts by mass of polystyrene block copolymer, 5 parts by mass of microporous glass, 10 parts by mass of toughening agent, 2 parts by mass of composite antioxidant, 3 parts by mass of lubricant and 3 parts by mass of other additives in a high-speed mixer, heating to 110 ℃, and mixing for 10 minutes; cutting the mixed material into pieces, discharging the pieces, conveying the pieces into forming equipment for preforming, and taking out the pieces after the forming pressure is 5MPa and 18S; adding the sheet material into a preheated mold, pressurizing to 6MPa at 150 ℃ on a flat vulcanizing machine, maintaining the pressure for 10min, decompressing and foaming, and cooling to normal temperature.

Example 6

The components by weight portion are as follows: mixing 90 parts by mass of polystyrene block copolymer, 5 parts by mass of microporous glass, 10 parts by mass of toughening agent, 2 parts by mass of composite antioxidant, 3 parts by mass of lubricant and 3 parts by mass of other additives in a high-speed mixer, heating to 110 ℃, and mixing for 10 minutes; cutting the mixed material into pieces, discharging the pieces, conveying the pieces into forming equipment for preforming, and taking out the pieces after the forming pressure is 5MPa and 18S; adding the sheet material into a preheated mold, pressurizing to 6MPa at 150 ℃ on a flat vulcanizing machine, maintaining the pressure for 10min, decompressing and foaming, and cooling to normal temperature.

Example 7

The components by weight portion are as follows: mixing 80 parts by mass of polystyrene block copolymer, 5 parts by mass of microporous glass, 10 parts by mass of toughening agent, 2 parts by mass of composite antioxidant, 3 parts by mass of lubricant and 3 parts by mass of other additives in a high-speed mixer, heating to 110 ℃, and mixing for 10 minutes; cutting the mixed material into pieces, discharging the pieces, conveying the pieces into forming equipment for preforming, and taking out the pieces after the forming pressure is 5MPa and 18S; adding the sheet material into a preheated mold, pressurizing to 6MPa at 150 ℃ on a flat vulcanizing machine, maintaining the pressure for 10min, decompressing and foaming, and cooling to normal temperature.

Comparative example 1

The components by weight portion are as follows: mixing 100 parts by mass of polystyrene, 5 parts by mass of microporous glass, 10 parts by mass of a toughening agent, 2 parts by mass of a composite antioxidant, 3 parts by mass of a lubricant and 3 parts by mass of other additives in a high-speed mixer, heating to 110 ℃, and mixing for 10 minutes; cutting the mixed material into pieces, discharging the pieces, conveying the pieces into forming equipment for preforming, and taking out the pieces after the forming pressure is 5MPa and 18S; adding the sheet material into a preheated mold, pressurizing to 6MPa at 150 ℃ on a flat vulcanizing machine, maintaining the pressure for 10min, decompressing and foaming, and cooling to normal temperature.

Measuring the impact strength of a sample block (the sample size is 80mm multiplied by 20m20mm) by using a simple beam pendulum impact strength tester; and (3) detecting the sound insulation performance of the sample according to a member weighting sound insulation quantity evaluation method in GB/T50121.

Table 1 shows the impact resistance and sound insulation properties of the impact-modified polystyrene.

Sample (I)	Impact Strength (KJ/m)2)	Weighting soundproof quantity (dB)
			Example 5	0.879	70
Example 6	0.792	65
			Example 7	0.705	63
Comparative example 1	0.568	42

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.