四甲基苯二甲基二异氰酸酯基水性聚氨酯的合成和性能

Synthesis and Properties of Waterborne Polyurethane Based Tetramethyl Xylene Diisocyanate

采用四甲基苯二甲基二异氰酸酯、聚酯二元醇和二羟甲基丙酸为原料,合成了一系列具有不同异氰酸根与羟基摩尔比(n(—NCO)/n(—OH))的聚氨酯乳液。研究了n(—NCO)/n(—OH)对水性聚氨酯性能的影响。结果表明,当该比值增加时,乳液的粒径增大,分布变宽,结晶性降低,耐热性下降,耐水性能呈现降低的趋势。当异氰酸根与羟基摩尔比为3时,四甲基苯二甲基二异氰酸酯基水性聚氨酯的乳液粒径为10～30 nm,膜的分解温度达到275℃,24 h吸水率低于10%。

A series of waterborne polyurethane （ WPU ） -OH（ n（-NCO）/n （-OH）） were synthesized using dispersions with different molar ratio of-NCO to tetramethyl xylene diisocyanate （ TMXDI）, polyester diol and dimethylolpropionic acid as raw materials. The effect of n（-NCO）/n（-OH） on the properties of WPU Was investigated. The experiment results showed that with the increase of n（-NCO）/n（-OH）, the particle size increased while the particle size distribution became wider; the crystallinity, thermostability and the water resistance tend to decrease as well. When n（-NCO）/n（-OH） was 3.0, the particle size of WPU based TXMDI was fallen in the range of 10 to 30 nm, the decomposition temperature and 24 h water absorption of WPU film were 275 ℃and below 10%, respectively.