Polyphenylene sulfide purifying method

Abstract

The invention discloses a polyphenylene sulfide purifying method. The method comprises the steps that: (1) acid-base neutralization is carried out, wherein a polymerization reaction product polyphenylene sulfide is cooled, an acid is added to polyphenylene sulfide, the pH of the mixture is controlled at 3-4, and a reaction is carried out while stirring; (2) solid-liquid separation is carried out, wherein a reaction product obtained in the step (1) is cooled and is subjected to solid-liquid separation, such that polyphenylene sulfide solid is obtained; (3) solvent washing is carried out, wherein an organic solvent is added to the obtained polyphenylene sulfide solid, and washing is carried out while stirring; (4) steam distillation and washing are carried out, wherein the polyphenylene sulfide obtained by washing in the step (3) is subjected to steam distillation under a negative-pressure condition, the residual organic solvent in the polyphenylene sulfide solid particles is recovered during the steam distillation process, and the polyphenylene sulfide is washed by using steam condensation water with a temperature of 75-85 DEG C when the content of the organic solvent is lower than 1%; and (5) drying and packaging are carried out, wherein qualified polyphenylene sulfide obtained in the step (4) is separated, dried, and packaged. Polyphenylene sulfide obtained with the method is advantaged in high electrical insulating property and high mechanical strength.

Description

technical field [0001] The invention relates to the production field of polyphenylene sulfide, in particular to a purification method of polyphenylene sulfide. Background technique [0002] Polyphenylene sulfide (PPS for short) has excellent thermal stability, good corrosion resistance, and excellent insulation and dielectric properties in high temperature and high humidity environments. Therefore, polyphenylene sulfide is widely used in fibers and electronic components. [0003] Polyphenylene sulfide is usually produced from sodium sulfide and p-dichlorobenzene. The polymerization reaction is completed at high temperature (usually around 300°C) and high pressure, and then purified and dried to obtain the finished product of polyphenylene sulfide. Since the directly produced polyphenylene sulfide contains a large amount of inorganic ion impurities, organic impurities and oligomers, which will affect the performance of subsequent polyphenylene sulfide, it must be effectively...

AI Technical Summary

Problems solved by technology

The disadvantages of the above purification method are: the purified polyphenylene sulfide still contains a large amount of inorganic ion impurities, oligomers and organic impurities, which seriously affect the electrical insulation and mechanical strength of polyphenylene sulfide