Preparation of polyimides by using mixtures of tetrahydrofuran and methanol and their properties

Abstract

Reaction conditions of the preparation of solutions of polyamic acids in the tetrahydrofuran/methanol mixed solvent (THF/MeOH) were studied. The polyamic acids were based on pyromellitic dianhydride and 4, 4′-oxydianiline. Transparent solutions were prepared at 5 wt% and lower concentrations of polyamic acid in the THF/MeOH mixture with component weight ratio ranging from 4:1 to 1:1. The properties of the final polyimide films were compared with those prepared by using N-methyl-2-pyrrolidone as the solvent.