Synthesis and Characterization of Thermotropic Polyethers and Copolyethers Based on 4,4′-dihydroxy-α-methylstilbene and Flexible Spacers Containing Odd Numbers of Methylene Units

Abstract

Abstract This paper describes the synthesis and characterization of thermotropic polyethers and copolyethers based on 4,4′-dihydroxy-α-methylstilbene (HMS) and flexible spacers containing odd number of methylene units [i.e., HMS-X/Y(A/B), where X is the number of methylene units in one of the spacers, Y is the number of methylene units in the other spacer, and A/B refers to the molar ratio of the two spacers]. The polyethers HMS-X are binary copolymers containing structural units derived from the two constitutional isomers of HMS and the flexible spacer. The binary copolymers HMS-X/Y(A/B) contain four structural units derived from combinations of the two constitutional isomers of HMS and the two flexible spacers. The following polymers and copolymers were synthesized and characterized: HMS-5, HMS-7, HMS-9, HMS-11, HMS-13(A/B), HMS-5/7(A/B), HMS-5/9(A/B), HMS-5/ll(A/B), HMS-7/9(A/B), HMS-9/ll(A/B), and HMS-9/13(A/B). All polymers had number average molecular weights higher than 15,000 and exhibited an enan...