Bisphenol-A polycarbonate/polydimethylsiloxane multiblock copolymers. II. Effects of siloxane oligomer structure on the properties of copolymers

Abstract

Polycarbonate-polydimethylsiloxane (PDMS) copolymers were synthesized by interfacial phosgenation of 2,2-bis(4-hydroxyphenyl)propane (bisphenol-A) with different types of PDMS oligomers including a,v-amino-organofunctional polydimethylsiloxane (AT-PDMS oligomer), a,v-hydroxy-organofunctional polydimethylsiloxane (HT-PDMS oligomer), and a,v-phenol-organofunctional polydimethylsiloxane (PT-PDMS oligomer). 1 H-NMR spectra indicated the conversion of AT-PDMS-PC copolymer was in the range between 85 and 95%, HT-PDMS-PC was 45-55%, and PT-PDMS-PC was 70-80%. It was found that the intrinsic viscosity of PDMS-PC copolymers decreased with increasing PT-PDMS oligomer content. The intrinsic viscosity, IV, also decreased with increasing cumylphenol content. The melt indices of PDMS-PC copolymers blended with neat PC increased with increasing PDMS-PC content and the copolymers showed good processability. Izod impact strength of PDMS-PC copolymer was improved while retaining tensile and flexural strengths of neat PC.