SYNTHESIS AND CHARACTERIZATION OF NOVEL POLYCARBONATE- POLYDIMETHYLSILOXANE BLOCK COPOLYMERS WITH CONTROLLED BLOCK LENGTHS AND AN ALTERNATING BLOCK ARCHITECTURE

摘要

A novel method to synthesize polycarbonate-polydimethylsiloxane (PC-PSiO) block copolymers with controlled block molecular weight and an alternating block architecture was investigated. The method investigated consisted of the synthesis of polycarbonate oligomers/polymers possessing allyl-functional endgroups and the subsequent coupling of the oligomers/polymers with hydride-terminated polydimethylsiloxane oligomers/polymers using hydrosilylation. Gel permeation chromatography and nuclear magnetic resonance spectroscopy were used to demonstrate successful block copolymer formation. Morphological characterization using atomic force microscopy showed nanoscale phase separation. A comparison of the optical properties of a PC-PSiO block copolymer produced with this method to that of a commercially available PC-PSiO block copolymer showed that the hydrosilylation-based process provided higher optical clarity, indicating smaller PDMS domains resulting from the more uniform block copolymer structure.