高固含量水性聚氨酯乳液的制备及其性能研究

摘要

以聚四氢呋喃二醇(PTMG)为软段,甲苯二异氰酸酯(TDI)为硬段,二羟甲基丙酸(DMPA)为亲水扩链剂,通过丙酮法制得了一系列聚氨酯预聚体,按不同n(—NCO)/n(—OH)(R值)及DMPA质量分数复配后分散成混合型水性聚氨酯乳液(WPU).考察R值、DMPA质量分数对复合型乳液及胶膜性能的影响.结果表明：不同R值复配所得乳液固含量没有明显提高；R=1.8,w(DMPA)=3%与w(DMPA)=6%的预聚体按质量比3/1复配,能制备固含量达48%左右的水性聚氨酯乳液,其胶膜的耐水性及机械性能处于中间水平.%With polytetramethylene glycol (PTMG) as soft segments, toluene di socyanate (TDI) as hard segments, dimethylol propionic acid (DMPA) as hydrophilic chain extender, a series of waterborne polyure⁃thane prepolymers were prepared by acetone method. In addition, prepolymers with different n(—NCO)/n(—OH) (R value) or DMPA content were formulated and dispersed into a series of waterborne polyurethane emul⁃sions (WPU). The influences of R value and DMPA content on the mixed WPUs and the film performance were investigated. The results showed that the solid content of WPUs with different R value weren′t im⁃proved obviously. When R value was 1.8, a stable WPU with about 48% solid content was obtained by mixing two prepolymers with 3% and 6% DMPA content according to a mass ratio of 3/1. The water resistance and mechanical property of the film ranked in the middle level.