US EPA

7573393 

Meetings & Symposia 

New approaches to the synthesis of N-substituted polybenzimidazoles 

Kane, JJ; Tomlinson, RC; Reinhardt, BA 

1990 

Chk 

Polymer Preprints (American Chemical Society, Division of Polymer Chemistry)
ISSN: 0032-3934 

Publ by ACS 

Washington, DC, USA 

Papers presented at the Washington, DC Meeting 1990 of the ACS, Division of Polymer Chemistry 

31 

2 

709-710 

English 

Aromatic N-substituted polybenzimidazoles have been studied comparatively little. In recent years our interest has been in the synthesis of N-aryl substituted rigid-rod polybenzodiimidazoles based on appropriately N,N′-di-substituted 1,2,4,5-tetraaminobenzene with rigid dicarboxylic acids and the development of innovative synthesis routes to them. The most successful technique reported to date is the two-step synthesis of Korshak and co-workers. It involves condensation of tetraamine with diacid chloride to give poly(o-anilino)amide which is subsequently cyclized and dehydrated to give polybenzimidazole. We have applied this technique with limited success to the synthesis of certain N,N′-diphenylsubstituted poly(benzodiimidazoles) and are currently exploring modifications to this technique as well as alternative synthetic techniques. This paper reports the results of condensation of a tetraamine bis-carbamate derivative and a dicarboxylic acid with the gentle dehydrating agent polyphosphoric acid trimethylsilyl ester (PPSE) and compares the properties of polybenzimidazole products of that synthesis to the same products prepared by modifications of Korshak's two-step procedure. 

Polymerization; Dehydrating Agent; Polybenzimidazoles; Polyphosphoric Acid Trimethylsilyl Ester; Aromatic Polymers