N,N-二甲基乙醇胺在本体消光型水性聚氨酯中的作用

Effect of N,N-Dimethylethanolamine on the Self-Matting Waterborne Polyurethane

本体消光型水性聚氨酯可以避免外加消光剂带来的弊端,是一种新型的功能性环保涂料。文中以异氟尔酮二异氰酸酯、聚己二酸丁二醇酯多元醇、二羟甲基丙酸(DMPA)、三羟甲基丙烷为预聚体原料,三乙胺和N,N-二甲基乙醇胺(DMEA)为中和剂,乙二胺基乙磺酸钠和水合肼为后扩链剂,采用预聚体分散法制备出水性聚氨酯(WPU)乳液。对不含DMEA的WPU样品系列与含有DMEA的WPU样品系列的消光性能进行了对比研究。结果表明,当DMEA的质量分数为1%时,不同DMPA用量的WPU乳液的平均粒径均保持在2100 nm左右,且粒径分布较窄,DMPA用量对其粒径和粒径分布影响不大;含有DMEA的WPU涂膜透过率相对有所降低,其表面凸起由球状颗粒紧密堆积而成,测得表面光泽度(60°)低于1。

Self-matting waterborne polyurethane（WPU）,a kind of novel functional coating,is able to avoid the defect of matting agents. WPU dispersions in which isophorone diisocyanate,poly-1,4-butylene adipate glycol,2,2-bis（hydroxymethyl） propionic acid（DMPA） and trimethylol propane were all used as raw materials of polyurethane prepolymer,triethyl amine and/or N,N-dimethylethanolamine（DMEA） as neutralizers,hydrazine hydrate and 2-[（2-aminoethyl） amino]ethanesulfonic acid sodium salt as post-chain extenders,were synthesized by prepolymer emulsification process. The matting comparison of a series of WPU dispersions without DMEA and another series of WPU dispersions containing DMEA were discussed to find out the effect of DMEA on the self-matting waterborne polyurethane. The results indicate that the mean particle size of WPU dispersions is maintained about 2100 nm,the particle size distribution is uniform and the DMPA content has slight effect on the particle size of WPU dispersions when the DMEA mass fraction is1%. The series of WPU containing DMEA have lower transparency,at the same time,spherical granules pack tightly in the surface morphology via SEM. It is most worth noting that the surface gloss at 60° of all samples containing DMEA is below 1.