Process for the thermal stabilization of acrylic fibers and films

摘要

An improved process for the thermal stabilization of an acrylic fibrous material or film is provided. A tetrasubstituted phosphonium salt which is capable of promoting the thermal stabilization is incorporated in a solution of the acrylic polymer prior to extruding the same to form a fibrous material or film, and the acrylic fibrous material or film having the tetrasubstituted phosphonium salt incorporated therein is heated in an oxygen-containing atmosphere until a thermally stabilized fibrous material or film is formed which is black in appearance, non-burning when subjected to an ordinary match flame and which is capable of undergoing carbonization. The presence of the tetrasubstituted phosphonium salt has been found to cause the thermal stabilization reaction to proceed at an accelerated rate.