不同阴离子亲水扩链剂合成的水性聚氨酯性能比较

Performance comparison of waterborne polyurethane synthesized by different anionic hydrophilic chain extenders

以二羟甲基丙酸(DMPA)、二羟甲基丁酸(DMBA)、二羟基磺酸盐(GS-7Q)为亲水扩链剂,采用单因素法合成一系列阴离子水性聚氨酯。通过比较乳液的粒径以及胶膜的耐水性、热稳定性、机械性能等,研究了不同的亲水扩链剂对合成的水性聚氨酯性能的影响。结果表明:DMBA作为亲水扩链剂合成水性聚氨酯(WPUB)相比于DMPA合成的水性聚氨酯(WPUP)反应时间缩短40%;获得稳定的水性聚氨酯乳液时,GS-7Q的用量比DMPA更少,仅需8%(扩链剂占所有—OH摩尔分数)即可维持乳液稳定。DMBA合成的水性聚氨酯的粒径较DMPA型的更细,其薄膜低温柔顺性更好; GS-7Q磺酸型水性聚氨酯(WPUH)薄膜的拉伸强度是羧酸型的4倍,耐热性能优于羧酸型水性聚氨酯,但低温柔顺性却不如羧酸型水性聚氨酯(WPUB,WPUP)。

Dihydroxy methyl propionic acid （ DMPA）, Dihydroxy methyl butyric acid （DMBA） and Dihydroxy sulfonate （GS-7Q） were used as hydrophilic chain extenders, a series of anionic waterborne polyurethanes （WPU） were synthesized and the effect of different hydrophilic chain extenders on the performances of WPU, such as the particle size of the final emulsion, water resistance, thermal stability and mechanical properties of film and so on were investigated in detail. The results indicate that reaction time of DMBA is 40% less than that of DMPA in the synthesis of polyurethane. The consume of GS-7Q is used less than DMPA to obtained a stable waterborne polyurethane, even 8% molar fraction of chain extenders account for all --OH of GS-7Q can maintain the stability of waterborne polyurethane. Particle size of WPUB is smaller than that of WPUP and low temperature flexibility is also superior to WPUP. The tensile strength of sulfonate waterborne polyurethane （WPUH） is four times that of carboxylic acid-based polyurethane. WPUH is superior to carboxylic acid type waterborne polyurethane in heat resistance, but low temperature flexibility is not as good as carboxylic acid type waterborne polyurethane （WPUB, WPUP）.