Synthesis and properties of new poly(dimethylsiloxane)-urea-polyamide multiblock copolymers by diisocyanate method

Abstract

New poly(dimethylsiloxane)-urea-polyamide multiblock copolymers based on poly(dimethylsiloxane) and polyamides were synthesized via diisocyanate route by two-step method. Isocyanate-terminated telechelic polyamide oligomers, prepared from a mixture of isophthalic acid and azelaic acid with 4,4′-methylenedi(phenyl isocyanate), reacted with α,ω-bis(3-aminopropyl)poly(dimethylsiloxane)s at room temperature to give the multiblock copolymers with inherent viscosities of 0.25–0.89 dl g−1. These multiblock copolymers were soluble in amide solvents, and transparent and ductile films could be cast from the solutions. The tensile strength and modulus of the films decreased with increasing the poly(dimethylsiloxane) content. © 1992, The Society of Polymer Science, Japan. All rights reserved.