Toluene diisocyanate has two isomers: 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (TDI). According to the different content of two isomers, there are three kinds of industrial specifications of products :(1) TDI-65 contains 65% of 2,4-TDI and 35% of 2,6-TDI; (2)TDI-80 contained 80% of 2,4-TDI and 20% of 2,6-TDI, which were the most common. (3) TDI-100: containing 100 % of 2,4 - TDI. Toluene diisocyanate interacts with water to produce carbon dioxide. Toluene diisocyanate is interacts readily with compounds containing active hydrogen atoms. Linear polyurethane or polyurethane resin formed by interaction with diols.