POLY(ETHYL ACRYLATE) LATEXES ENCAPSULATING NANOPARTICLES OF SILICA .2. GRAFTING PROCESS ONTO SILICA

Emulsion polymerization of ethyl acrylate has been carried out in the presence of two kinds of silica, either functionalized by treatment wi th methacryloylpropyltrimethoxysilane, or not. Both polymerization and grafting kinetics were followed. A part of the polymer is covalently grafted onto silica only if the latter is functionalized and the graft ing process takes place at the beginning of the process. The grafted p olymer is tightly linked to the silica surface as a succession of smal l-sized loops. High-molecular-weight non-grafted polymer is also produ ced with compressed conformation, its radius of gyration being much la rger than the thickness of the polymer layer encapsulating the silica.