Synthesis and characterization of silicon‐containing phenylated soluble aramids

New high molecular weight (inherent viscosities, 1.21–0.50 dL/g) aramids having silicon and pendant phenyl groups were synthesized by low temperature interfacial polycondensation technique involving the reaction of acid chlorides: bis(4‐chlorocarbonylphenyl)dimethylsilane and bis(3‐chlorocarbonylphenyl)dimethylsilane with diamines: 2,5‐bis(4‐aminophenyl)‐3,4‐diphenyl‐thiophene and bis(4‐aminophenyl)ether. Copolyamides were obtained by using different proportions of these diamines. All the polymers were completely soluble in organic solvents such as N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidone, and N,N‐dimethylformamide. Thermal properties were evaluated by thermogravimetry which showed no weight loss below 325°C in both air and nitrogen atmospheres.