Preparation of poly(methyl methacrylate)-Silica nanoparticles via differential microemulsion polymerization and physical properties of NR/PMMA-SiO2 hybrid membranes

Poly(methy methacrylate) (PMMA)-SiO2 nanoparticles were prepared via differential microemulsion polymerization. The effects of silica loading, surfactant concentration, and initiator concentration on monomer conversion, particle size, particle size distribution, grafting efficiency, and silica encapsulation efficiency were investigated. A high monomer conversion of 99.9% and PMMA-SiO2 nanoparticles with a size range of 30 to 50 nm were obtained at a low surfactant concentration of 5.34 wt% based on monomer. PMMA-SiO2 nanoparticles showed spherical particles with a core-shell morphology by TEM micrographs. A nanocomposite membrane from natural rubber (NR) and PMMA-SiO2 emulsion was studied for mechanical and thermal properties and pervaporation of water-ethanol mixtures. PMMA-SiO2 nanoparticles which were uniformly dispersed in NR matrix, significantly enhanced mechanical properties and showed high water selectivity in permeate flux. Thus, the NR/PMMA-SiO2 hybrid membranes have great potential for pervaporation process in membrane applications. POLYM. ENG. SCI., 2017. (c) 2017 Society of Plastics Engineers