Study On Green Synthesis Process Of Polyurethane

In this paper, the process conditions of the polyurethane with poly propylene polyol(PPC) and 1,6-hexamethylene carbamate (HDC) as the raw material is studied on the basis of the world's first laboratory transesterification polycondensation of polyurethane. Poly propylene polyols is synthesized from carbon dioxide, and 1,6-hexamethylene carbamate (HDC) is also synthesized by the route of carbon dioxide. So in this issue, the polyurethane is synthesized by carbon dioxide that has a very great significance on the current global greenhouse gas emissions of carbon dioxide. And the transesterification polycondensation process has a clean and green features compared to the traditional method of phosgene. It can meet current rising environmental requirements.After choosing poly propylene polyol and 1,6-hexamethylene carbamate (HDC) as raw materials, the researches of the selection of catalyst and catalyst mixture, the molecular weight of PPC, the vacuum adjust, reaction temperature, reaction time, catalyst concentration change are taken in this paper. The optimal process conditions of the reaction of HDC and PPC is:use dibutyltin dilaurate as catalyst, the dosage is 0.0497wt%, molar ratio of HDC to PPC is 1:1, the agitator speed is 120 r/m. Use 2 steps to polycondensation. In the first step, with 8 kPa and 100℃and react for 1 hour. In the second step, with 0.04 kPa and 133℃and polycondensation for 1.5 hours. Finally get the polyurethane with highest Mw=58470. Molecular weight distributing is very wide. And the product looks like adhesive.