聚氨酯大分子表面活性剂组成结构对WPUA胶粒结构及其膜性能的影响

Effect of composition and structure of macromolecular polyurethane surfactant on structures and properties of waterborne polyurethane-acrylate latex

设计了聚合度相同,但组成结构不同的聚氨酯大分子表面活性剂(PUS),并将此大分子表面活性剂用于甲基丙烯酸甲酯(MMA)的聚合,制备出乳胶粒结构不同的水性聚氨酯-丙烯酸酯乳液(WPUA),乳液经干燥成膜后得到不同的样膜。应用透射电镜(TEM)、Zeta纳米粒度仪及旋转黏度计对WPUA乳胶粒形貌、粒径和乳液黏度进行了测试与表征,通过ATR-FTIR、吸水率测试、万能材料试验机和紫外-可见光谱仪对WPUA膜的结构、耐水性、力学性能和物理老化行为进行了研究。结果表明,PUS组成结构会影响WPUA乳胶粒的结构,进而影响形成的WPUA膜的性能。WPUA-PCDL乳胶粒的核壳结构明显,其膜的力学和耐老化性能较好。

Macromolecular polyurethane surfactants（PUS） with equal degree of polymerization but different compositions and structures were designed and synthesized by reacting PCDL, PBA and PPG with isophorone diisocyanate（IPDI）. Methyl methacrylate（MMA） monomer was polymerized in PUS micelles to prepare WPUA emulsions and dried latex films with different latex structure and morphology. Transmission electron microscopy（TEM）, Zeta nanosizer, and rotating viscometer were employed to characterize latex morphology, particle size, and shear viscosity of WPUA emulsions. ATR-FTIR, water absorption measurement, electromechanical universal testing machine, and UV-Vis spectroscopy were employed to characterize structures, water resistance, mechanical properties, and physical aging behaviors of WPUA films. PUS composition and structure had a significant influence on morphology and structure of WPUA latexes and properties of dried films. Distinct core-shell structure was achieved in WPUA latex using PCDL-based PUS as macromolecular surfactant. WPUA-PCDL film exhibited good mechanical and aging-resistant properties.