| abstract |
Nanoparticles of crosslinked and functionalized vinyl polymer, which can be used in particular as a reinforcing filler in a polymeric matrix, said nanoparticles being characterized in that said vinyl polymer is a copolymer of at least the following monomers, all of which are copolymerizable by free-radical polymerization: a non-aromatic vinyl monomer 'A'; - a monomer 'B' which has a functional group denoted by Z and having formula =Si-X, where X represents a hydroxyl or hydrolysable group; a crosslinking monomer 'C', in other words a monomer which is at least difunctional in respect of said polymerization. Said vinyl polymer is preferably a polymethacrylate, in particular a copolymer of methyl methacrylate (monomer A), trimethoxysilylpropyl methacrylate (monomer B) and ethylene glycol dimethacrylate (monomer C), which is in the form of nanobeads with a diameter of between 10 and 100 nm. By virtue of a very low density, this vinyl polymer filler enables a reduction in the weight of the polymeric compositions, especially those of elastomers, without deterioration in the reinforcement, and with a substantial reduction in hysteresis. |