A Study On The Green Synthetic Approach Of Polycarbonate And Polyurethane

Recentally, environmental problems whether products or production process have gotten growing attentions.The non-phosgene and/or non isocyanate approach procedure of polycarbonate and polyurethane aroused extensive attention due to the exemptation and/or limitation of usage of phosgene and isocyante, which are harmful to the environment and human health.Biphenol-A monobuthylcarbonate (I) and biphenol-A dibuthylcarbonate ( II ) were synthesized by using bisphenol A(BPA) and dibuthyl carbonate(DBC) as the raw materials. Their structures were characterized by NMR. A novel non-phosgene process for producing bisphenol-A polycarbonate(PC) was developed through the self transesterification of I and II and co-transesterification of BPA and II. Gel permeation chromatography (GPC) and thermo gravimetric analysis (TGA) were used to measure the molecular weights and thermodynamic properties. The self transesterification of II is the better way to prepare the higher molecular weight PC. The Mw of PC obtained from the self-polymerization of II at 230℃for 6 h is up to 3.1*104. This non-phosgene route is a novel alternative preparation for polycarbonate. Bisphenol A diol(III) and bisphenol A carbonate(IV) were synthesized by using bisphenol A(BPA),ethylene carbonate(EC) and dimethyl carbonate(DMC) as the raw materials. Their structures were characterized by FT-IR and NMR. A novel nonphosgene process for producing bisphenol A polycarbonate(PC) was developed through the self transesterification of IV and co-transesterification of III and IV. Gel permeation chromatography (GPC) and differential scanning calorimetry thermogravimetric analysisc (DSC-TGA) were used to measure the molecular weights and thermodynamic properties. The average number molecular weight of PC obtained from the self-polymerization of IV at 210℃for 25 h is up to 1.256*104 .The introduction of -CH2 CH2 -unit into the main chain can reduce the Tg of PC. The obtained PC has a good thermal stability.A novel green synthesis approach of polyurethane and polycarbonate urethanes has been proposed through the reaction of carbonate with diols and diamine. The experimental results indicate that it is feasible to prepare polyurethane and polycarbonate urethanes through this novel green synthesis approach. The results based on gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) show that the degree of polymerization is up to 160 and the maximum temperature of maximum decomposition rate is up to 529℃.