Radical graft polymerization of methyl methacrylate on inorganic fillers initiated by surface S-methyl-N,N-diethyldithiocarbanate groups☆

Abstract A comparative study was made of the kinetics and mechanism of the photoinitiated radical graft polymerization in the system Silochrome (containing surface S-methyl-N,N-diethyldithiocarbamate groups)-MMA, and similarly for photopolymerization in the corresponding homogeneous system S-ethyl-N,N-diethyldithiocarbamate-MMA. Photochemical decay of the surface initiator in presence of the monomer causes simultaneous initiation of graft- and homopolymerization. Attachment of the initiator to the filler surface leads to a reduction in the rate of bimolecular termination of kietic chains during the graft polymerization. This reduction is equal to one order compared with polymerization in the homogeneous solution. It also leads to the disappearance of chain transfer to surface S-methyl-N,N-diethyldithiocarbamate groups.