脂肪族水性聚氨酯的制备及性能研究

以异佛尔酮二异氰酸酯(IPDI)和聚醚二醇(PPG)为主要原料、二羟甲基丙酸(DMPA)为亲水扩链剂和乙二胺(EDA)为小分子扩链剂,采用预聚体分散法制备出一种水性聚氨酯(WPU)乳液。考察了n(-NCO)∶n(-OH)比例、EDA扩链方式等对WPU稳定性、玻璃化转变温度、力学性能和耐水性等影响。结果表明:将EDA先溶于水中,采用乳化与扩链同时进行的工艺,并且当n(-NCO)∶n(-OH)=1.5∶1时,WPU乳液稳定性好、粒径(14 nm)较小且分布较窄,WPU胶膜的力学性能(拉伸强度为3.683 MPa、断裂伸长率为347%)和耐水性(吸水率为19.7%)俱佳。

Study on preparation and properties of aliphatic waterborne polyurethane

With isophorone diisocyanate(IPDI) and polypropylene glycol ether(PPG) as main materials,dimethylol propionic acid(DMPA) as hydrophilic chain extender,ethylenediamine(EDA) as small molecule chain extender,a waterborne polyurethane(WPU) emulsion was prepared by prepolymer dispersing method.The influences of molar ratio of n(-NCO)∶n(-OH) and the EDA's chain extension method on the emulsion stability,glass transition temperature,mechanics properties,water resistance of WPU were researched.The results showed that the WPU had better emulsion stability,smaller particle diameter(14 nm) and narrower distribution,better mechanics properties(tensile strength at 3.683 MPa and elongation at break at 347%) and water resistance(water absorption at 19.7%) when emulsification and chain extension were concurrent after EDA was introduced into water,and molar ratio of n(-NCO)∶n(-OH) was 1.5∶1.