Dipole–dipole interaction directed liquid crystalline polymers. I. Aliphatic poly(carbonate‐sulfone)s based on 1,3‐bis(3‐hydroxypropylsulfonyl)propane

Abstract

AbstractAliphatic poly(carbonate‐sulfone) homo‐ and copolymers were prepared from 1,3‐bis(3‐hydroxypropylsulfonyl)propane (Diol‐333) and various alkanediols. The copolymers are random in nature since they were prepared by melt copolymerization. Both the homopolymer and the copolymers exhibited multiple reproducible first‐order transitions during differential scanning calorimetry (DSC) heating scans, but most of them exhibited only single exotherm during cooling scans. Typical schlieren textures were observed when these polymers were cooled from their isotropic melts. The copolymers have wide‐angle x‐ray diffraction (WAXD) patterns almost identical to that of the homopolymer except in the low‐angle spacing, indicating their packing in the crystalline domain in similar. DSC, cross‐polarized optical microscopy, and WAXD revealed that these polymers were smectic liquid crystalline at room temperature. Since aliphatic poly(carbonate‐sulfone)s are flexible linear polymers with no rigid rod components, the liquid crystalline phase formation is probably directed by the dipole–dipole interactions between sulfone groups in adjacent chains. © 1994 John Wiley & Sons, Inc.