Metal Salts For The Crosslinking Agent On Polyacrylate Coating Performance

Acrylate polymer emulsions are widely used in coatings,adhesives and so on because of their good lightfastness, acid-alkali resistance and corrosion resistance. At present, copolymer emulsions of (meth)acrylate, vinyl acetate/(meth)acrylate and styrene/(meth)acrylate are the most to be used. However, acrylate polymer still have many drawbacks such as poor water resistance, flexibility and durability, which has a great influence on the waterproof performance of coatings. A series of acrylate polymer emulsions were prepared through the way of pre-designing particle and property of polymer, introducing a small quantity of functional monomer, selecting emulsification systems and initiation systems and emulsion polymerization technology. They can raise the ratio of permormance to price of coatings and decrease VOC content in emulsion paint. Therefore, there are great meanings in theory and practice. The present thesis mainly concerned some ambient curable emulsion coatings, and the crosslinking mechanisms of different systems have been studied in detail. Three kinds of emulsions with active carbonyl groups, including ketonic, aldehyde and acetoacetylate group have been prepared by copolymerization of styrene, acrylic acid, butyl acrylate and the corresponding functional monomer respectively. The reaction parameters and the monomer composition on the properties of the polymeric films were mainly studied.Different crosslinked coatings have been prepared at room temperature and compared their properties. It was found that the crosslinked coatings showed excellent properties, and the best results were observed for the crosslinking systems of the ketonic/hydrazede group and the acetoacetate/amino group. However, the aldehyde-contained emulsion showed lower stability due to the high activity of the aldehyde group. Furthermore, the optimal molar ratio of the functional groups and the drying time were found out.The processes of the crosslinking reaction were confirmed by IR analysis. The acidic catalytic crosslinking pathways were provided.The inorganic particle-doped styrene-acrylic emulsions have been prepared by in-situ polymerization, and the properties of emulsions prepared by different methods were compared. The amount of the inorganic particle was studied.