Recovering poly(arylene sulfide) oligomers from a poly(arylene sulfide) reaction mixture

摘要

Poly(arylene sulfide) oligomers are recovered in a process comprising steps of:(a) dehydrating an aqueous admixture of alkali metal hydroxide such as sodium hydroxide, and alkali metal bisulfide such as sodium bisulfide, in a polar organic solvent such as N-methyl-2-pyrrolidone (NMP), wherein the molar ratio of alkali metal hydroxide to alkali metal bisulfide is about 0.90:1 to about 1.05:1 prior to dehydration and 0.99:1 to about 1.05:1 after dehydration;(b) reaction of at least one polyhalo-substituted aromatic compound such as p-dichlorobenzene with the mixture from step (a) under a polymerization conditions to produce a reaction mixture;(c) addition of a phase separation agent such as water, to the reaction mixture to produce a phase-separated poly(arylene sulfide) mixture;(d) cooling the mixture from step (c) to produce a slurry of particulate poly(arylene sulfide) and poly(arylene sulfide) oligomers in a liquid;(e) separating particulate poly(arylene sulfide) from the slurry of step (d) leaving a dispersion of poly(arylene sulfide) oligomers in a liquid; and(f) filtering the dispersion of step (e) to recover the poly(arylene sulfide) oligomers therefrom.