DEVOLATILIZATION

摘要

A polymer melt may be devolatilized to less than 500, preferably less than 150 ppm of residual volatile material by injecting into the melt a n amount of a super critical fluid greater than the amount of residual volatil e material in the melt, typically not more than about 10 weight %, and passing the melt through a flash chamber devolatilizer at a pressure of 1.6 x 10 3 Pascals (Pa) (12 mm of Hg) or less at a temperature of from 200.degree.C to 350.degree.C.