Ionically crosslinked core-shell particles for waterborne humidity-sensitive coatings

Abstract

Using conventional functional monomers, such as methylacrylic acid (MAA), styrene (St), methyl methacrylate (MMA) and butyl acrylate (BA), the core-shell styrene-acrylic ionomer particles (PSA) are prepared by two-step emulsion polymerization. Then, using zinc ion as ionic crosslinker of the carboxylate groups from the shell layer, a novel self-crosslinked core-shell ionomer latex (PSA-Zn) has been successfully prepared and characterized by dynamic light scattering and transmission electron microscopy, whose components were also confirmed by FT-IR and TGA. After mixing pigments and porous fillers, the cheap, readily available and environment friendly coatings (PSA-Zn-C) has been prepared. Compared to PSA and EF-AAC coatings, the adhesive force, hardness and thermal stability of PSA-Zn film are better. Moreover, the core-shell ionomer coating (PSA-Zn-C) can significantly decrease or increase relative humidity in response to environmental humidity in the artificial climate box, and this is a promising candidate for development of waterborne humidity-sensitive coatings.