Synthesis and characterization of aramids containing a-terthienylene units by palladium-catalysed polycondensation of dibromo-a-terthiophene,aromatic diamines and carbon monoxide

Abstract

Aramids containing,-terthienylene units were prepared by palladium-catalysed polycondensation of dibromo-a-terthiophene, aromatic diamnines and carbon monoxide. Polymerizations were carried out in N,N-dimethylacetamide (DMAc) with triphenyl-phosphine and 1,8-diazabicyclo[5,4,0)-7-undecene (DBlU) in the presence of palladium catalyst, and gave a series of aramids with inherent viscosities up to 0.87 dl g-J under mild conditions. The structures of the polymers were determined by IR and '³C NMR spectroscopy. The polymers were soluble in strong acids and dipolar aprotic solvents. Thermogravimetry of the polymers showed excellent thermal stability, and the 10% weight losses of the polymers in air were observed to be above 410C. The glass transition temperatures of the polymers ranged from 185 to 231C.