DMPA对PPG-DMPA-IPDI水性聚氨酯性能的影响

以聚氧化丙烯二醇(PPG-2000)、二羟甲基丙酸(DMPA)和异佛尔酮二异氰酸酯(IPDI)为主要原料,采用一锅法合成水性聚氨酯(WPU)预聚体及高剪切乳化法制备了PPG-DMPA-IPDI水性聚氨酯(WPU).研究了DMPA用量对WPU乳液的Zeta电位和粒径分布的影响,并采用红外光谱(FT-IR)、高效凝胶渗透色谱(GPC)和差热-热重分析(TGA-DTA)对WPU胶膜性能进行了表征.结果表明:当中和度为100%、异氰酸酯指数R(NCO/OH)值为3.7、DMPA质量分数为5%~8%时,制得的WPU乳液的分散稳定性较好.随着DMPA用量的减少,WPU的粒径增加,热稳定性降低,微相分离程度减弱.一锅法合成WPU预聚体并高剪切乳化法与分步合成并高速搅拌乳化法相比,反应时间较短.

Effect of DMPA on Properties of PPG-DMPA-IPDI Waterborne Polyurethane

A series of PPG-DMPA-IPDI waterborne polyurethane( WPU) were synthesized by using polypropylene glycol( PPG-2000),2,2-dimethylolpropionic acid( DMPA) and isophorone diisocyanate( IPDI) via an one-pot reaction and a high shear emulsification method. The effects of the DMPA content on the Zeta potential and the particle size distribution of the waterborne polyurethane were studied,and the WPU were characterized by the Fourier transform infrared spectroscopy( FTIR),gel permeation chromatography( GPC),thermal analysis( TGA-DTA). The results showed that the WPU exhibites optimal dispersion stability at the neutralization degree of100%,NCO/OH molar ratio( R) of 3.7,and the DMPA amount of 5% ~ 8 %. With the decreasing of DMPA amount,the particle size of WPU increases whereas their thermal stability and degree of microphase separation decreases. In addition,by using the one-pot reaction and the high shear emulsification method,the reaction time is shorter than that using the step-wise reaction and the high speed stirring emulsification method.