CN110204723B

CN110204723B - Preparation method of heat-resistant polyphenylene sulfide

Info

Publication number: CN110204723B
Application number: CN201910589214.XA
Authority: CN
Inventors: 郭瑞斌; 欧阳美璇; 莫尊理; 刘妮娟; 董奇兵; 陈颖
Original assignee: Northwest Normal University
Current assignee: Northwest Normal University
Priority date: 2019-07-02
Filing date: 2019-07-02
Publication date: 2021-07-30
Anticipated expiration: 2039-07-02
Also published as: CN110204723A

Abstract

The invention provides a preparation method of hollow spherical heat-resistant polyphenylene sulfide, which comprises the steps of firstly carrying out high-temperature oxygen-isolation treatment on sodium sulfide nonahydrate to obtain anhydrous sodium sulfide, then taking potassium carbonate, sodium carbonate and lithium chloride as a combined catalyst, uniformly mixing the anhydrous sodium sulfide with the prepared anhydrous sodium sulfide solution, adjusting the pH of the solution to be = 9-10 by using sodium hydroxide, then heating to 220-225 ℃ under the protection of nitrogen, and carrying out constant-temperature reaction for 6-8 h; and washing, filtering and drying to obtain the hollow spherical polyphenylene sulfide. Tests prove that the hollow spherical polyphenylene sulfide has the melting point of 297 ℃, has good heat resistance, has larger specific surface area, and can be more compatible with other substances, so that various groups (inorganic macromolecules/metal oxides and the like) can be easily introduced into a hollow shell, and the hollow spherical polyphenylene sulfide is used for preparing polyphenylene sulfide composite materials modified by various groups.

Description

Preparation method of heat-resistant polyphenylene sulfide

Technical Field

The invention relates to a preparation method of polyphenylene sulfide, in particular to a preparation method of heat-resistant polyphenylene sulfide with a hollow spherical structure, and belongs to the field of material preparation.

Background

Polyphenylene sulfide (abbreviated as PPS) is a polymer containing a p-phenylene sulfide repeating structural unit in a molecule, is a novel functional engineering plastic, and is widely applied to the fields of electronics, automobiles, machinery and chemical engineering. pps has the advantages of high mechanical strength, high temperature resistance, high flame retardance, strong chemical resistance and the like; has the advantages of hardness, brittleness, high crystallinity, flame retardancy, good thermal stability, high mechanical strength, excellent electrical property and the like. Polyphenylene sulfide is an amphiphobic substance, and has very strong rigidity in the structure of the alternate arrangement of benzene rings and sulfur atoms, and basically does not dissolve any solvent, thereby determining the macroscopic property, namely high mechanical strength. Thus, the polyphenylene sulfide may be present as a catalyst support or composite substrate.

Many methods are currently used for synthesizing PPS, such as self-polycondensation of halosulfur phenolate, melt polymerization of p-halodiphenyl and sulfur, electrophilic reaction of sulfur and benzene, solution polycondensation of alkali metal sulfide and p-dihalobenzene (sodium sulfide method), solution polycondensation of sulfur and p-dichlorobenzene (sulfur solution method), polymerization of diphenyl disulfide under the action of Lewis acid, and the like. The sodium sulfide method and the sulfur solution method are currently used for industrial production, and the prepared polyphenylene sulfide has the microscopic forms of lamellar, spherical, flower-shaped, reticular and the like, and the size can be expanded to a few micrometers or can be reduced to a nanometer level. However, polyphenylene sulfide of these structures has poor heat resistance, thus limiting its applications.

Disclosure of Invention

The invention aims to provide a preparation method of heat-resistant polyphenylene sulfide with a hollow spherical structure.

The preparation method of the hollow spherical polyphenylene sulfide comprises the steps of firstly dispersing sodium sulfide nonahydrate in N-dimethyl pyrrolidone under the condition of continuously introducing nitrogen, and reacting at 150-160 ℃ for 1.5-2 hours to obtain an anhydrous sodium sulfide solution; adding a combined catalyst into the anhydrous sodium sulfide solution, uniformly mixing, adjusting the pH of the solution to be = 9-10 by using sodium hydroxide, heating to 70-80 ℃, adding p-dichlorobenzene, and uniformly stirring; then heating to 220-225 ℃, and reacting for 6-8 h at constant temperature; and after the reaction is finished, washing, filtering and drying to obtain the hollow spherical heat-resistant polyphenylene sulfide.

The combined catalyst consists of lithium chloride, potassium carbonate and sodium carbonate, and the mass ratio of the lithium chloride to the potassium carbonate is 4: 1-3.5: 1; the mass ratio of the lithium chloride to the potassium carbonate is 3.5: 1-3.0: 1. The mass ratio of the combined catalyst to the sodium sulfide nonahydrate is 1: 4-1: 5; the mass ratio of the p-dichlorobenzene to the sodium sulfide nonahydrate is 1: 1.5-1: 2.

In order to achieve a better dispersion effect, the combined catalyst is dispersed in N-dimethyl pyrrolidone according to the mass-volume ratio of 1: 40-1: 45g/mL, and then added into an anhydrous sodium sulfide solution. The gas velocity of continuously introducing nitrogen is 10-15 mL/min.

FIG. 1 is a scanning electron microscope image of the hollow spherical polyphenylene sulfide prepared by the present invention. As can be seen from FIG. 1, polyphenylene sulfide is in the form of hollow spheres, and is uniformly distributed, and has a large-scale flat structure. Therefore, various groups (such as metal ions, macromolecular inorganic substances or organic substances and the like) can be easily introduced into the gaps, so that the polyphenylene sulfide composite material modified by various groups can be prepared.

Table 1 shows the heat resistance of polyphenylene sulfides with different morphologies. As can be seen from Table 1, the heat resistance of the hollow spherical polyphenylene sulfide prepared by the invention is obviously superior to that of polyphenylene sulfides with other shapes.

The invention uses lithium chloride, sodium carbonate and potassium carbonate as combined catalyst, which has great promotion effect on nucleophilic substitution reaction; the formed hollow spherical polyphenylene sulfide has larger specific surface area and can be more compatible with other substances, and meanwhile, the hollow spherical structure effectively prevents the heat transfer efficiency of the hollow spherical polyphenylene sulfide, so that the melting point of the hollow spherical polyphenylene sulfide is improved, the hollow spherical polyphenylene sulfide is endowed with good heat resistance, and the application of the polyphenylene sulfide is widened.

Drawings

FIG. 1 is a scanning electron microscope image of hollow spherical polyphenylene sulfide prepared by the present invention after drying at 0 ℃.

Detailed Description

The preparation, morphology and the like of the polyphenylene sulfide with the hollow spherical structure are further described by specific examples.

(1) Preparation of anhydrous sodium sulfide: weighing 79.5 g of sodium sulfide nonahydrate, adding the sodium sulfide nonahydrate into 180mL of N-dimethyl pyrrolidone, continuously introducing nitrogen under oxygen-proof protection (nitrogen flow rate is kept at 10 mL/min), reacting for 1 h at 150-160 ℃ to obtain a green anhydrous sodium sulfide solution, cooling, and pouring into a reaction kettle;

(2) preparation of the combined catalyst: 5.933 g of anhydrous lithium chloride, 1.658 g of anhydrous potassium carbonate and 1.732 g of anhydrous sodium carbonate are weighed, sealed and mixed uniformly to prevent oxidation and deliquescence;

(3) preparing hollow sphere polyphenylene sulfide: dissolving the combined catalyst in 230mL of N-dimethylpyrrolidone, adding the mixture into a reaction kettle, uniformly mixing, adding sodium hydroxide at room temperature under stirring (the stirring speed is 40 r/min), adjusting the solution to be alkaline (pH = 9-10), heating to 70 ℃, and adding 44.1 g of p-dichlorobenzene under stirring to obtain a dark green solution; after the reaction kettle is sealed, continuously introducing nitrogen (the nitrogen introduction rate is 10 mL/min) under stirring (the stirring speed is 900 r/min) to replace the air in the reaction kettle; then heating to 220 ℃, keeping the temperature and reacting for 6 hours, wherein the solution is black; repeatedly washing with deionized water and ethanol, filtering at 60 deg.C, and drying at 0 deg.C to obtain 10.5 g hollow spherical polyphenylene sulfide. Melting point 297 ℃. The scanning electron microscope image of polyphenylene sulfide is shown in FIG. 1, and polyphenylene sulfide is in hollow sphere shape and is uniformly distributed.

Claims

1. A preparation method of heat-resistant polyphenylene sulfide comprises the steps of dispersing sodium sulfide nonahydrate in N-dimethyl pyrrolidone under the condition of continuously introducing nitrogen, and reacting at 150-160 ℃ for 1.5-2 hours to obtain an anhydrous sodium sulfide solution; adding a combined catalyst into the anhydrous sodium sulfide solution, uniformly mixing, adjusting the pH of the solution to be = 9-10 by using sodium hydroxide, heating to 70-80 ℃, adding p-dichlorobenzene, and uniformly stirring; then heating to 220-225 ℃, and reacting for 6-8 h at constant temperature; after the reaction is finished, washing, filtering and drying to obtain hollow spherical heat-resistant polyphenylene sulfide; the combined catalyst consists of lithium chloride, potassium carbonate and sodium carbonate, and the mass ratio of the lithium chloride to the potassium carbonate is 4: 1-3.5: 1; the mass ratio of the lithium chloride to the sodium carbonate is 3.5: 1-3.0: 1.

2. The method of claim 1, wherein the heat-resistant polyphenylene sulfide is prepared by: dispersing the combined catalyst in N-dimethyl pyrrolidone according to the mass-volume ratio of 1: 40-1: 45g/mL, and adding the mixture into anhydrous sodium sulfide solution.

3. The method of claim 1, wherein the heat-resistant polyphenylene sulfide is prepared by: the mass ratio of the combined catalyst to the sodium sulfide nonahydrate is 1: 4-1: 5.

4. The method of claim 1, wherein the heat-resistant polyphenylene sulfide is prepared by: the mass ratio of the p-dichlorobenzene to the sodium sulfide nonahydrate is 1: 1.5-1: 2.

5. The method of claim 1, wherein the heat-resistant polyphenylene sulfide is prepared by: the gas velocity of continuously introducing nitrogen is 10-15 mL/min.