Synthesis and Characterization of Thermotropic Liquid Crystalline Polyurethane Based on 4,4'-bis(6-hydroxyhexoxy)biphenyl and Aliphatic Diols

摘要

1.Introduction Iimura and his co-workers were the first who report the synthesis of main chain thermotropic liquid crystalline polyurethanes prepared by polyaddition of 3,3'-dimethyl-4,4'-biphenyl diisocyanate with ω-alkanediols[1]. Later, thermotropic liquid crystalline polyurethanes (LCPUs) are being investigated with much interest owing to their application potential. It is well known that hard segment of thermoplastic polyurethane can form thermotropic liquid crystalline phase when properly selected diisocyanate and diol are used for polyaddition reaction[5-7]. This article reports on the characterization of a series of thermotropic liquid crystalline polyurethane (LCPUs) were synthesized by polyaddition reaction of 2,4-toluene diisocyanate with 4,4'-bis(6-hydroxyhexoxy)biphenyl (BHHBP) and aliphatic diols in N, N'-dimethylformamide (DMF) solution. Synthetic route.