NEW SINGLE-STEP PROCESS FOR POLYBENZIMIDAZOLE SYNTHESIS

Aromatic benzimidazole polymers have been prepared by reaction of the corresponding tetraamine and diester in refluxing sulfolane or phenyl sulfone. The convenience of using these sulfone solvents together with the good yields, high viscosities and absence of crosslinking make this procedure an attractive new route to this class of polymers. The preparation by this procedure of poly left bracket 2,2 prime -(m-phenylene)-5,5 prime -bibenzimidazole right bracket , poly- left bracket 2,2 prime -(p-phenylene)-5,5 prime -bibenzimidazole right bracket , poly left bracket 2,2 prime -(m-phenylene)-5,5 prime -di(benzimidazole) ether right bracket , and poly left bracket 2,2 prime -(m-phenylene)-5,5 prime -di(benzimidazole) ketone right bracket is described.