Research on Non-phosgene Synthesis of Polyether Polyurethane Elastomer
|School||East China University of Science and Technology|
|Keywords||non-phosgene PTMEG polyurethane transesterification polycondensation|
A non-isocyanate method is provided for the preparation of polyether polyurethane elastomer in this thesis. Compared with the traditional technology, this one uses PTMEG(Mw=2000) and1,6-hexamethylene dicarbamate (HDC) as raw material avoids the utilization of highly toxic chemicals. HDC can be prepared by dimethyl carbonate (DMC)， which comes from carbon dioxide and is environmentally friendly. Thus, during the whole process which is green-synthesis procedure and will bring strong environmental protection benefit, we succeed in avoiding using the poisonous and harmful materials from fountainhead,Prepolymerization process and polycondensation process were investigated separately with chain extender added. Groups of experiments show that the optimum conditions of process are:HML-lwas chosen as catalyst and the dosage was0.15wt%; the molar ratio of raw materials was1.0:0.9:0.1for HDC:PTMEG:BDO, nitrogen was fed into the system during the whole process. For the prepolymerization process, the reaction pressure were controlled under2.6kPa for lh and1.4kPa for0.5h respectively, the temperature was80℃-90℃-100℃and every temperature needed to be kept for half an hour. The polycondensation process was maintained under0.2kPa for1.75h at185℃. Finally, the polyurethane elastomer was prepared with a Mw of90616, tensile strength of10.44Mpa, tensile modulus of4.03MPa and elongation at break of977.78%.