Non-phosgene Synthesis of Polyurethane Elastomer
|School||East China University of Science and Technology|
|Keywords||polyurethane non-phosgene transesterification polycondensation PTMEG|
In this study, we provide a transesterification polycondensation synthesis process for the preparation of thermoplastic polyurethane using HDC and PTMEG (Mw=2000) as raw materials. Compared to the traditional isocyanate process, this new technology avoided the use of extremely toxic phosgene. Furthermore, the raw material HDC could be produced by 1, 6-Hexylenediamime and DMC, and the synthesis of DMC has been fully studied in our laboratory and successfully industrialized via the reaction of methanol and carbon dioxide. Thus, it was a new environmentally friendly and cost effective synthesis process using carbon dioxide comprehensively.The influences of type and quantity of catalyst, reaction time, reaction temperature, pressure and mol ratio of raw material on intrinsic viscosity, transmittance and hardness of product have been discussed. The optimal conditions are:The preparation was studied over 0.1 wt% dibutyltin oxide as catalyst, composition of reaction mixture was set to 1:1 for HDC:PTMEQ the prepolymerization has been taken under 2KPa at 100℃for 1h, then the polycondensation has been taken under 0.2KPa at 175℃for 1h, the polyurethane with a Mw of 54090, poly-dispersity of 1.611 and 90.3% transmittance was achieved.