中文摘要：

采用预聚法合成了一种新型的水性聚氨酯乳液，扩链剂以粉末方式无污染加入。研究了配方中异氰酸酯基和羟基的量的比（-NCO／-OH）、反应温度、二羟甲基丙酸含量（DMPA％）等对水性聚氨酯乳液的粘度、粒径和涂膜吸水率等性能的影响。初步研究结果表明，随着-NCO／-OH的增大，乳液粘度下降，乳胶粒的粒径增加，涂膜的吸水率下降；随预聚反应温度升高，分子链中达到异氰酸酯基理论含量时间减小，但是温度越高越易发生副反应；随着DMPA％的增加，乳液粘度升高，乳胶粒的粒径上降，但最终趋于稳定，涂膜的吸水率升高。

英文摘要：

A new waterborne polyurethane emulsion was synthesized by prepolymerization; the chain- extender was directly added in powder without solvent pollution. The influencing factors including the ratio of isocyanate to hydroxyl group content （--NCO/--OH） , the reaction temperature, and the 2, 2-dimethylol propionic acid content （ DMPA % ） on target prepared emulsions viscosity, particle diameter, and water absorption were experimentally investigated during and after preparation. The results showed that： （ 1 ） the emulsion viscosity and water absorption were decreased when the --NCO/--OH ratio （ the ratio of isocyanate to hydroxyl group content ） was increased, but the particle diameter was increased. （2） The reaction rate was faster when the temperature was higher, but the side reaction was more easily arisen. （3） The emulsion viscosity and water absorption were increased when the 2, 2-dimethylol propionic acid content was increased, but the particle diameter was decreased.