影响聚氨酯乳液稳定性能若干因素的探讨

Discussion on factors affectingstability of polyurethane emulsion

从乳液反应、理化性能、应用效果三方面入手 ,探讨了影响 PU- D系列聚氨酯乳液的稳定性的若干因素。结果表明 ,控制 NCO/OH在 1 .2～ 1 .3,扩链反应温度在 6 0～ 80℃ ,搅拌速度在 1 80 r/min以上 ,可提高反应阶段的乳液稳定性。控制乳液中游离 - NCO含量在 1 %～ 2 % ,p H值在弱碱 (7～ 8)范围内 ,可提高乳液的贮存稳定性。加入适量的防光剂 ,保存期延长。

The factors affecting stability of PU-D series polyurthane emulsion were discussed in terms of emulsionreaction, physical and chemical properties , and application effect. The emulsion with good stability wasobtained when NCO/OH was 1.2~1.3, chain extending temperature was 60~80℃, stir speed wasabove 180r/min. The storage stability of the emulsion could be improved when free -NCO content inthe emulsion was 1%~2%, pH value was 7~8,And addition of light stabilizer could prolong storage period of the emulsion.