水性聚氨酯的制备及其影响因素的研究

Study on Preparation and Influence Factors of Waterborne Polyurethane

以2,4⁃甲苯二异氰酸酯、聚乙二醇(PEG)、二羟甲基丙酸(DMPA)、三乙胺(TEA)等为原料,制备了一种水性聚氨酯(WPU)。用核磁共振对WPU膜进行表征,研究了异氰酸酯指数(R值)、DMPA用量和pH值对WPU性能的影响。结果表明:初聚R值为2.0、总体R值为1.2时,WPU乳液性能较好;随着DMPA用量增加,WPU乳液粒径减小、稳定性增强,胶膜的拉伸强度增加,断裂伸长率降低;pH值增大,WPU乳液粒径减小。

A series of waterborne polyurethanes(WPU)was synthesized with 2,4⁃toluene diisocyanate(TDI),polyethylene glycol(PEG),dimethylolpropionic acid(DMPA)and triethylamine(TEA).1H⁃NMR was used to characterize the WPU.The effects of isocyanate index(R),DMPA amount and pH value on the properties of WPU were studied.The results showed that WPU emulsion performance was better as the primary polymerization R was 2􀆰0 and the total R was 1􀆰2.With the increase of DMPA amount,the particle size of WPU emulsion de⁃creased,the stability increased,the tensile strength of the film increased and the elongation at break decreased.With the increase of pH value,the particle size of WPU emulsion decreased.