A thermo-kinetic study on acrylic copolymer nanocomposite particles containing GMA-modified nanosilica prepared via miniemulsion polymerization

Abstract Silica/polyacrylic nanocomposite particles are the most attractive hybrid materials due to their outstanding physical and chemical properties. This paper deals with the chemical incorporation of glycidyl methacrylate-modified silica nanoparticles (GMA-modified SNPs) into acrylic copolymer through miniemulsion polymerization with a well dispersion. Fractional conversions and rate of polymerizations were investigated to study the role of GMA-modified SNPs on the polymerization kinetics by probable radical engagement. DSC analyses revealed some enhancement in Tg for the obtained polyacrylic nanocomposite particles because of the occurrence of limited chain flexibility. However, appearance of an exothermic peak above 90 °C in these thermograms was attributed to the possible radical generation by unreacted and trapped methacrylate groups of GMA on the surface of SNPs and their subsequent involvement in the progress of exothermic grafting reactions. Besides, the effect of GMA-modified SNPs on thermal degradation and thermo-oxidative stability of the prepared nanocomposites were evaluated by TGA. Storage modulus in the glassy and rubbery regions before and after thermal treatment were studied by DMTA and the results confirmed the above observations too.