Synthesis of nanocylinders consisting of graft block copolymers by the photo-induced ATRP technique

Photoinduced atom transfer radical polymerizations (ATRP) of t-butyl methacrylate (BMA) were carried out, initiated by model initiator benzyl N,N-diethyl-dithiocarbamate (BDC) in the presence of CuCl/bipyridine (bpy) under UV irradiation. We performed the first-order time-conversion plots in this polymerization system, and the straight line in the semilogarithmic coordinates indicated a first-order in the monomer. The molecular weight of poly(t-butyl methacrylate) (PBMA) increased in direct proportion to monomer conversion. The molecular weight distribution (M-w/M-n) of PBMA was about 1.3. The initiator efficiency, f, was close to 1.0, which indicated that no side reactions occurred. A copper complex, CuCl/bpy, reversibly activated the dormant polymer chains via a NN-diethyldithiocarbamate (DC) transfer reaction such as Cu(DC)Cl/bpy, and it was dynamic equilibrium that was responsible for the controlled behavior of the polymerization of BMA. On the basis of this information, we established a preparation method of nanocylinders consisting of graft block copolymers by grafting from photoinduced ATRP of multifunctional polystyrene having DC pendant groups with vinyl monomers [first monomer, BMA; second monomer, styrene or methyl methcrylate (MMA)]. We have carried out the characterization of such nanocylinders in detail. (C) 2004 Wiley Periodicals, Inc.