Influence of silica surface modification on poly (butyl acrylate-co-methyl methacrylate)/silica emulsion stability

The application of emulsion polymerisation for nanocomposite material synthesis is still a problem since it is difficult to achieve emulsion stability and desirable morphology. In this work, the in situ emulsion polymerisation procedure was optimised in order to prepare stable polyacrylate (PA) systems with 15 wt% of modified silica. The surface of the silica was modified with non-ionic emulsifier (NE), cationic initiator 2,2'-azobis (2-amidinopropane) dihydrochloride (AIBA) and 3-methacryloxypropyltrimethoxysilane (MPS). The adsorption conditions, the influence of monomer mode addition, the rate of pre-emulsion addition, monomer/water ratio, the pH and the amount of anionic emulsifier (SDS) on polyacrylate/silica emulsion stability were investigated. The results showed that the most significant influence on emulsion stability have the amount of anionic emulsifier and silica surface modification. This work contains practical knowledge regarding adsorption of non-ionic emulsifier, emulsion stability, filler surface modification and in situ emulsion polymerisation with high amount of modified silica (15 wt%) and monomer/water ratio 70/100.