Smectic Characteristics of Main-Chain Polyesters as Elucidated from a Variation of Layer Thickness with Carbon Number of Aliphatic Spacer in a Wide Range,5 to 20

Abstract

We prepared the main-chain type of TP-n polyesters, which are based on the terphenyl dicarboxylic acid and alkane diols with the carbon number of n = 5–20. All the TP-n polyesters form a smectic liquid crystal, exhibiting the well known odd–even oscillation with respect to the thermodynamic parameters of transitions and smectic structure. From the x-ray patterns of the oriented fibres, the S_A and S_CA structures were identified for the even and odd series of TP-n respectively. The structural characteristics of the polymeric S_A and S_CA phases are presented by examining the variation of layer spacing with n in a wide range of n = 5 to 20.