Evolution of the film properties of 3‐methacryloxypropyl trimethoxysilane containing waterborne acrylic coatings during storage

Abstract

AbstractThe use of alkoxysilane monomers is one of the most attractive methods to obtain one‐pot self‐crosslinkable latexes for coating applications. The copolymerization kinetics shows that the alkoxysilane monomer is effectively incorporated into the copolymer. However, the hydrolysis and condensation reactions that give the latex the self‐crosslinking ability can also prematurely happen. As a result, the microstructure of the latex, and consequently of the dried polymer film, will change during the storage. Herein, the evolution of key film properties, such as, water uptake and tensile strength as a function of the storage time of latexes with different alkoxysilane monomer loadings is presented. As storage time increases, there is an improvement on the mechanical properties, obtaining a harder polymer as the result of the development of the hydrolysis and condensation reactions during the first 4 weeks. However, for more extended storage periods (17 weeks) there is a significant decrease in the mechanical performance, because the crosslinking in the latex has developed enough to hinder the film formation.