Mesogenic diol of 4,4'-bis(6-hydroxy hexoxy)biphenyl (BP-6) having flexible chain length of six was synthesized. And Two types of liquid crystalline polyurethanes(MPU-6s) were prepared from BP-6 and 4,4'-diphenylmethane diisocyanate(MDI) by solution p...
Mesogenic diol of 4,4'-bis(6-hydroxy hexoxy)biphenyl (BP-6) having flexible chain length of six was synthesized. And Two types of liquid crystalline polyurethanes(MPU-6s) were prepared from BP-6 and 4,4'-diphenylmethane diisocyanate(MDI) by solution polycondensation.
Intrinsic viscosities of MPU-6s were in the range of 0.23~0.56 dL/g. The mesomorphic behavior of MPU-6s were investigated by DSC, X-ray, polarizing microscopy and MPU-6s didn't show mesophase but 'virtual liquid crystal' on slow heating and slow cooling. As the molecular weight of MPU-6s decreases, both the crystallization rate and the melting crystallization temperature of MPU-6s increase.