磺酸型水性聚氨酯胶粘剂的制备及性能研究

Synthesis and application of waterborne polyurethane adhesive modified with sulfonic groups

采用预聚体合成法,以二羟甲基丙酸(DMPA)和2,4-二氨基苯磺酸钠(SDBS)为亲水扩链剂,制备了一种水性聚氨酯预聚体,再将高分子乳液乙烯-醋酸乙烯酯(EVA)与去离子水均匀混合对其乳化,制得固含量高达50%磺酸型水性聚氨酯鞋用胶粘剂。利用红外光谱对SDBS和聚氨酯的结构进行了表征,证实了SDBS作为亲水扩链剂引入聚氨酯链上。研究了SDBS用量对胶粘剂的剥离强度、耐热性及稳定性的影响。当SDBS用量从0增加到2.5%时,皮革初期剥离力由20.98N上升至89.23N,其耐热性和稳定性也有所增强。透射电镜图片显示,与EVA共乳化后的磺酸型水性聚氨酯(SWPU)乳液分散均匀,呈圆球状。

Waterborne polyurethane prepolymer were synthesized by a prepolymer process using dimethylol propionic acid （DMPA） and 2,4-diaminobenzenes sulfonic acid sodium salt（SDBS） as hydrophilic chain extender agent. And the sulfonic polyurethane adhesive emulsion with solid content of 5＆% was obtained when emulsified with the mixture of ethylene vinyl acetate copolymer（EVA）and deionized water. The structure of the film was confirmed by means of Fourier transform infrared spectroscopy （FT-IR）. The results indicated that the SDBS has been successfully introduced into the polyurethane chain. The influence of the SDBS content on the primeval peel strength, heat resistance and stability of the adhesive emulsion and films were studied. The results show that when SDBS content increases from 0 to 2.5% ,the primeval peel strength increases from 20.98 to 89. 23N,heat resistance and stability of the adhesive emulsion and films also increases. Transmission electron microscope（TEM） photos show that SWPU emulsions emulsified with EVA dispersed well with neat appearance.