Polycondensation Reaction of Aromatic Bis(phenylurethane)s with Diols

Abstract

Polyurethanes containing benzimidazole units were prepared by the polycondensation reactions of bis(phenylurethane)s with diols. The reactions were initiated after dissolution of urethanes in initially molten diols. The reaction products solidify as the reactions proceed, and the polymerization reactions proceed in solid state at such two stages, the previously reported reaction of bis(phenylurethane) with diamines or with diamino dicarboxylic acids. It was elucidated by this study, that the latter stage of polymerizations proceeds at above the glass transition temperatures of the formed polyurethanes. The polyurethanes containing benzimida zole units have an excellent thermal stability.