Structural modifications of segmented poly(hydroxyether-siloxane) copolymers

Abstract

Hydroxyether linked copolymers were synthesized from α,ω-bis(aminopropyl)polydimethyl diphenylsiloxane oligomers and diglydicylether of bisphenol-A (DGEBA). The siloxane oligomers were synthesized by the bulk coequilibration of the various weight percents cyclic dimethylsiloxane tetramer (D4) with cyclic diphenylsiloxane tetramer (D4″) using a basic catalyst. The molecular weight and functionality was controlled by the incorporation of 1,3-bis(aminopropyl)-tetramethyldisiloxane end blocker. The copolymers containing low diphenylsiloxane compositions have two Tg's suggesting a microphase separation. Networks containing higher diphenylsiloxane compositions show a single phase morphology. The mechanical behavior of these copolymers is influenced by the composition changes. © 1988 Springer-Verlag.