“Liquid crystalline” thermosets from 4,4′‐bis(2,3‐epoxypropoxy)biphenyl and aromatic diamines

Pure 4,4′‐bis(2,3‐epoxypropoxy)biphenyl ( 1 ) has been synthesized and its mesophase behaviour has been investigated. 1 forms a monotropic nematic mesophase with a virtual clearing temperature of 109°C. 1 has been cured with 2,4‐diaminotoluene ( 3 ), 4,4′‐diaminobiphenyl ( 4 ), and 4‐aminophenyl 4‐aminobenzoate ( 5 ) to investigate the possibility of formation of anisotropic networks. Virtual clearing temperatures of the diamines indicate that liquid crystalline thermosets (LCT's) might be obtained with 4 and 5 . Crystallization of oligomeric products from the isotropic melt of 1 with 3 or 4 , respectively, occurred on isothermal curing without formation of a mesophase, while a nematic LCT was obtained with 5 .