Synthesis and Properties of Functional Waterborne Polyurethane Coatings
|School||East China University of Science and Technology|
|Keywords||Waterborne fluorinated polyurethane Emulsion polymerization Properties Polymerizable fluorocarbon surfactant|
First, the PU prepolymer was synthesized by isophorone diisocyanate (IPDI), polyoxypropylene glycol (PPG-1000),1,4-butanediol (BDO), dimethylol propionic acid (DMPA) and -COOH was introduced into the prepolymer. Then a type of alcohol containing double bond (HEMA) was used to cap the prepolymer and the polymer was dispersed into emulsion. Finally, the fluorinated polyurethane-acrylate emulsion with core-shell structure was obtained by emulsion polymerization. During the preparation of latex films, the aziridine cross-linking agent was used to improve the properties of films by curing the materials.The structures and performance of different emulsions were studied by FTIR, Particle size analysis, stabilky test, viscosity test and the latex films were characterized by contact angle, water absorption rate and Tensile properties. The relationship between structures and properties was studied. The results showed that the functional waterborne coatings performs well with good mechanical properties, strong water-resistant ability and less environment pollution.During emulsion polymerization, a novel kind of polymerizable fluorocarbon surfactant, sodium perfluorinated-4-methyl-6-vinyl-3,6-dioxide butyl sulfate, were prepared to replace the traditional surfactants such as PFOA. The results showed that the kind of fluorocarbon surfactant has excellent surface properties, and the emulsion with this emulsifier performs equivalent to the traditional emulsion. The polymerizable surfactant could be used as alternatives of PFOA and reduce pollution to environment.