Study on preparing the latexes composed of polyvinyl chloride-acrylate copolymers with core-shell structure for increasing water resistance of its coating

Abstract

The insufficient water resistance of waterborne coatings is an important factor limiting their applications. Herein, the latexes composed of polyvinyl chloride-acrylate copolymer (PVC-ACM) with a core-shell structure have been synthesized via seeded emulsion polymerization, and coupling agents were introduced into the polymerization to reinforce the core-shell interfacial bonding and increasing the water resistance of the PVC-ACM coatings. The effects of quantity, types of surfactants, and introducing way of coupling agent into seed emulsion polymerization on the performance of the latex and the water resistance of the PVC-ACM coatings were investigated. The results determined that latex particles composed of PVC-ACM copolymers exhibit a core-shell structure when the PVC content reaches 40 wt%, and the comprehensive performance of the latex reaches its optimum when a combined surfactant system consists of 2.5 wt% SR-10/CO-436 while the introduction amount of coupling agent KH570 is 2 wt%. Moreover, the water contact angle of coatings consisting of PVC-ACM latex reached 92.3°, and the 24-h water absorption rate decreased to 2.4 %. This study presented a promising approach for developing the new waterborne coatings with superior water resistance.