Two series of thermotropic liquid crystalline polyureas were synthesized by the copolymerization of benzidine (or o-tolidine),1,6-hexane diamine and 2,4-toluene diisocyanate.

为合热致液晶聚脲，以含液晶基元的联苯二（或联邻甲苯）、1，6-己二、2，4-甲苯二异氰为原料进行合。

Toluene diisocyanate (TDI) is one of the most useful kinds of isocyanateth that is produced by the method of phosgenation of amine.

甲苯二异氰(TDI)异氰化合物中应用最广泛的品种之一,其工业生产主要采用光化法。