New Preparation Process And Properties Of Cyclic Carbonate And Non-isocyanate Polyurethane

Polyurethane is a kind of synthetic resin material confronted with the concept of green,because of the toxic and moisture sensitive isocyanate,though widely used in various fields including plastic,rubber,foam,fiber,coating,adhesives and functional polymer materials.But non-isocyanate polyurethane obtained from cyclocarbonate and polyamine satisfies the growing awareness of environmental friendly and safety well.Five-membered cyclic carbonates are often prepared by CO₂ and epoxy resin under high temperature and high pressure for a satisfactory conversion rate.Therefore,in this paper,high equipment requirements and costs were avoided by preparing cyclocarbonate under atmospheric pressure.This article mainly explored the technological conditions and the process of preparing five-membered cyclic carbonates as well as characterization of modified NIPU,including the following aspects:The multi-functional five-membered cyclic carbonates was prepared and the effect of polymerization process on the properties of the resin was studied.The polyol worked as a core and reacted with acid anhydride,and then with epichlorohydrin（ECH）to synthesis O-chloro alcohol resins.Then studied the influence of polyols and reaction conditions on the properties of resins.It was found that more chloro hydroxyl groups were grafted,the resin viscosity was higher.And it was also found that the conversion rate of five-membered cyclic carbonate resin was the highest when chlorohydrin resin and NaHCO₃ were used the raw materials,the ratio of two was 1:2（mole ratio）,3%of TBAB as a catalyst,DMSO as a solvent,after reacted at 90℃for 3h,and then at 100℃for 5h.The more hydroxyl groups the polyol possessed,the more carbonate group was grafted,the greater the steric resistance and the lower the conversion rate.Using infrared spectroscopies（FTIR）to characterize the structure of the resin,infrared spectra of cyclic carbonate resin has a characteristic absorption peak near 1800cm^-1,NMR showed conversion of cyclic carbonate resin quantitatively,and DSC analysis showed that the glass transition process was in the range of 9.5-24.6℃.Proportion and curing conditions of cyclic carbonate resin and amine to synthesis NIPU were studied.It was found that self-made four functional cyclocarbonate resin（CC-PE）and PEI input at a molar ratio of cyclic carbonate/-NH₂=1:1,DMF as a solvent,150℃curing for half an hour,the film’s hardness was 2H,adhesion was 1 grade,flexibility was 1mm,and alkali resistance was excellent,but resistance of water,acid and alcohol was poor.The structure of NIPU was characterized by infrared spectroscopy.And the TG analysis showed that its weight loss initiated at 200℃.To further improve the performance of NIPU film,the hybrid nonisocyanate polyurethane（HNIPU）was prepared by added the modified agent,and found that the modified HNIPU（the ratio of CC-PE and E-20 was 60:40）film exhibited good properties,the film hardness was high up to 2H,with strong adhesion,excellent flexibility,high impact resistance of 100cm/kg and excellent chemical resistance.The transparent film was smooth and shiny.Part of the HNIPU could also direct curing even at room temperature.