UV-curable organic silicone grafting modified waterborne polyurethane acrylate: Preparation and properties
Yun Shen, Jin Liu, Zhen Li, Jialu Luo, Shiwu Wang, Jinyang Tang, Ping Wang, Di Wang, Xianbiao Wang, Xianhai Hu, Fengjun Zhang
Abstract
The organosilicon grafting copolymerization waterborne polyurethane acrylate composite coating (WPUA@KH570) with high surface properties was prepared by the UV curing method from mixing silicone monomer surface-modified ZnO (Si@ZnO) as photoinitiator to waterborne polyurethane acrylate (WPUA) emulsion. The effects of the polyurethane isocyanate index (R), the addition amount of hydrophilic chain elongator DMBA (w DMBA ), the ratio of PU/PA on the stability of the synthesized WPUA emulsion were explored. The properties of the WPUA@KH570 composite coatings with different contents of organosilicon surface-modified ZnO were characterized by the particle size distribution meter, FTIR, XRD , SEM, UV–Vis–NIR spectrophotometer, contact angle (CA) and water absorption rate (WAR). The results showed that when R = 1.4, w DMBA = 0.04 and PU/PA = 0.6, the WPUA emulsion had an excellent stability. When the content of organosilicon modified ZnO reached 1.5 wt%, the CA increased to 90.6°, the WAR decreased to 15.4 %, and the absorbance reached 0.5. The WPUA@KH570 composite coating could be changed from hydrophilic to hydrophobic, which can step further promoted the surface properties, water resistance and UV absorption.