Salt byproduct separation during formation of polyarylene sulfide

摘要

Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent.

主权项

1. A method for forming a polyarylene sulfide comprising:
performing a first polymerization in which a dihaloaromatic compound is reacted with an alkali metal sulfide or hydrosulfide in an organic amide solvent to form a mixture that includes a polyarylene sulfide and a salt; contacting the mixture with a filter that separates the mixture into a filter cake and a filtrate, wherein the filtrate contains at least a portion of the polyarylene sulfide and the filter cake contains at least a portion of the salt, wherein the filter is maintained at a pressure that is elevated above atmospheric pressure and at a temperature of from about 220° C. to about 300° C.; and performing a second polymerization in which the polyarylene sulfide from the filtrate is reacted with an alkali metal sulfide or hydrosulfide.