Method of Polyarylene Sulfide Precipitation

摘要

A method for forming a polyarylene sulfide is described. The method can include a multi-step cooling and precipitation process in which the cooling rate of the solution that carries the polymer is decreased during a portion of the overall cooling. This slower cooling period can encompass at least a portion of the period during which the polymer precipitates from the solution. The precipitation process can form polyarylene sulfide particles with good particle integrity and a narrow particle size distribution, which can reduce fines and improve downstream processing and final product characteristics.

主权项

1. A method for forming a particle including a polyarylene sulfide comprising:
polymerizing a first sulfur-containing monomer and a first dihaloaromatic monomer in an organic amide solvent to form a polyarylene sulfide prepolymer; polymerizing the polyarylene sulfide prepolymer with a second dihaloaromatic monomer and a second sulfur-containing monomer to form a polyarylene sulfide in a polymerization solution; cooling a precipitation solution comprising the polyarylene sulfide, water and an organic solvent at a first cooling rate to a first temperature in a first cooling step; following the first cooling step, cooling the precipitation solution at a second cooling rate to a second temperature in a second cooling step, wherein the second cooling rate is slower than the first cooling rate; and following the second cooling step, cooling the precipitation solution at a third cooling rate to a third temperature in a third cooling step, wherein the third cooling rate is faster than the second cooling rate; wherein the polyarylene sulfide particle precipitates out of the precipitation solution over at least a portion of one or more of the first cooling step, the second cooling step, and the third cooling step.