Polymer-silicate nanocomposites produced by in situ atom transfer radical polymerization

Polymer-silicate nanocomposites were synthesized with atom transfer radical polymerization (ATRP). An ATRP initiator, consisting of a quaternary ammonium salt moiety and a 2-bromo-2-methyl propionate moiety, was intercalated into the interlayer spacings of the layered silicate. Subsequent ATRP of styrene, methyl methacrylate, or n-butyl acrylate with Cu(I)X/N,N-bis(2-pyridiylmethyl) octadecylamine, Cu(I)X/N,N,N',N',N"-pentamethyldiethylenetriamine, or Cu(I)X/1,1,4,7,10,10-hexamethyltriethylenetetramine (X = Br or Cl) catalysts with the initiator-modified silicate afforded homopolymers with predictable molecular weights and low polydispersities, both characteristics of living radical polymerization. The polystyrene nanocomposites contained both intercalated and exfoliated silicate structures, whereas the poly(methyl methacrylate) nanocomposites were significantly exfoliated. (C) 2004 Wiley Periodicals, Inc.