UV固化PUA/EA核壳复合乳液的制备与性能

Preparation and Properties of UV Curable PUA/EA Core-Shell Emulsions

以亲水性聚氨酯丙烯酸酯(PUA)预聚体为高分子乳化剂,与环氧丙烯酸酯(EA)树脂混合后,采用相反转乳化法制备了UV固化PUA/EA复合乳液。利用傅里叶变换红外光谱对水性PUA合成过程以及复合乳液UV固化前后进行了表征,表明得到了目标产物且UV固化良好。透射电镜(TEM)测试表明,复合乳液随EA含量不同呈不同的不规则的核壳结构。讨论了羧基含量、中和度以及EA树脂含量对乳液相反转过程、PUA预聚体的乳化能力、复合乳液及其固化膜性能的影响。结果表明,PUA预聚体的乳化能力随羧基含量的增加而增加,但超过2.3%后变化不再明显;相反转过程中体系黏度与电导率的最大值均随羧基含量的增加而增加,且出现得越来越晚;中和度增加,复合乳液的粒径逐渐减小,稳定性先变好后变差,乳液的黏度增加而固化膜的耐水性降低;EA含量增加,乳液粒径降低,涂膜的光固化速率提高,固化膜硬度增加,柔韧性变差,耐水及耐热性能均先增加后降低。

Waterborne UV curable polyurethane acrylate（PUA）/epoxy acrylate（EA） hybrid emulsions were prepared by a phase inversion method, which uses waterborne PUA as the emulsifier and mixed with EA. FT-IR was applied to characterize the structure of the PUA resin and the hybrid emulsion before and after UV curing. Transmission electron microscopy （TEM） results show that the emulsion particles have an anomalous core-shell structure, which changes with EA contents. The effects of-COOH content, neutralization degree and EA content were also investigated. The results show that the emulsification performance of PUA is improved with the increase of -COOH content. However, it becomes stable when the content is above 2.3%. The maximum viscosity and electrical conductivity of the emulsion increase with the -COOH content. With the increase of neutralization degree, the particle size of the emulsion decreases and the stability improves and then becomes less stable. The viscosity of the system also increases with the increase of neutralization degree, but the water resistance decreases. Furthermore, the particle size and the flexibility of the cured film decrease with the increase of EA content, while the UV curing rate and hardness of the film increase when EA content increases. The water and heat resistance both increase and then decrease with the increase of EA content.