聚氨酯树脂材料中的异氰酸酯

Polyurethane has an excellent flexibility, adhesiveness and high impregnation rate, widely utilized such as automotive films, insulating materials, and paints. The polyurethane resin is a polymer which involves the urethane bond, obtained by the polymerization reaction between polyisocyanate and polyol (also called, polyester or polyether). ･･―NCO + HO―･･ 􀃆 ･･―NHCOO― … (1) ―NCO + H2N―･･ 􀃆 ･･―NHCONH― … (2) ･･H2N―(excessive) + HCl 􀃆 HCl・H2N― … (3) (B－D)×K×F×M S×1000 A1 ： Content of isocyanate groups (%) F ： Factor of the titrant D ： Volume of the titrant consumed (mL) M ： Molarity of the titrant (0.5) B ： Blank value (mL) S ： Weight of the sample added (g) K ： Formula weight of isocyanate (42.02)