Synthesis and characterization of liquid crystalline polyester and epoxy block copolymer

A liquid crystalline block copolymer ( BCPE) was synthesized from bis-phenol-A epoxy oligomer and liquid crystalline polyester (PBHT) which was prepared from polyhexamethylene-bis-(4-oxybenzoates) and terephthaloyl dichloride by solution polymerization. The intrinsic viscosity (eta(inh)) of the polymers was determined using an ubbelohde viscometer in phenyl hydroxide/1,1,2,2-tetrachloroethane mix solvent (1 : 1) at 30degreesC, and the results showed that the eta(inh) values of PBHT and BCPE are 0.16 dL/g and 0.46 dL/g respectively. FTIR analysis identified the reaction between bis-phenol-A' epoxy oligomer and PBHT. The crystalline properties of polymers were investigated with DSC and WAXD, and the results found that the crystallinity of BCPE is inferior to that of PBHT due to addition of amorphous epoxy. Thermotropic liquid crystalline nematic phase textures of polymers were observed under a polarizing microscope with hot stage.