Synthesis of CaCO3–P(MMA–BA) nanocomposite and its application in water based alkyd emulsion coating

Abstract

As part of broader effort to synthesize a new class of water-based composite, hybrid emulsion polymerization was carried out with acrylic monomers [methyl methacrylate (MMA), n-butyl acrylate (BA)]. Nanocomposite of P(MMA–BA)/nano CaCO3 was synthesized by in situ emulsion polymerization. Water-based alkyd coating with various proportions nano CaCO3, P(MMA–BA) and its nanocomposite was formulated. Extent of polymerization with and without nano CaCO3 was measured using gravimetric method. Thermal properties of neat polymer, nanocomposite and coating films were evaluated by TGA and DSC, DTA analysis. Uniform dispersion of nano CaCO3 in polymer matrix was ensured from SEM/TEM images. Incorporation of nanoparticles to hybrid polymer and nanocomposite to alkyd emulsion showed significant enhancement in mechanical and thermal properties. Dual role of nanocomposite in coating; as a partial binder and a filler to improve property profile of neat coating has been reported.