Synthesis and Properties of Block Copolymers Based on Carboxyl-Terminated Polydimethylsiloxane and Aromatic Polyamides

Abstract

Polysiloxane-aramid block copolymers were synthesized by a one-pot two-step method of direct polycondensation using triphenyl phosphite and pyridine as the condensing agents. Amine-terminated aramid oligomers were prepared by the reaction of 3,4′-oxydianiline and isophthalic acid, and subjected to polycondensation with α,ω-bis(10-carboxydecyl) olydimethylsiloxane to give block copolymers with inherent viscosities of 0.13—0.25 di g−1. They were soluble in amide-type solvents like N,N-dimethylacetamide and gave translucent and ductile films by casting from the solutions. These block copolymers start to decompose around 300°C. These properties are very similar to those of block copolymers derived from α,ω-bis(3-aminopropyl)polydimethylsiloxanes and carboxyl-terminated aramid oligomers.