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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。
With isophorone diisocyanate (IPDI) and polyether diol (PPG) as main raw materials, dimethylolpropionic acid (DMPA) as hydrophilic chain extender and ethylenediamine (EDA) as small molecule chain extender , An aqueous polyurethane (WPU) emulsion was prepared by prepolymer dispersion method. The effects of n (-NCO): n (-OH) ratio, EDA chain extension method on the stability of WPU, glass transition temperature, mechanical properties and water resistance were investigated. The results showed that the EDA was first dissolved in water, and the emulsification and chain extension were carried out at the same time. The stability of WPU emulsion was good when n (-NCO): n (-OH) = 1.5:1, ) Is smaller and has a narrower distribution. The mechanical properties of WPU film (tensile strength of 3.683 MPa, elongation at break of 347%) and water resistance (water absorption of 19.7%) are all excellent.