Poly(ethylene glycol)methyl ether methacrylate (PEOMA) and oligo(propylene glycol)-4-nonylphenyl ether acrylate (OPOPhNA) were co-polymerized by atom transfer radical polymerization (ATRP). Grafting through method was employed in the presence of CuBr/HMTETA or CuBr/PMDETA catalyst/ligand complex in anisole at 70 degrees C. It yielded a heterografted copolymers containing hydrophilic PEO and hydrophobic OPOPhNA side chains with polymerization degree DP = 68-315 in the presence of PMDETA and DP = 48-195 in the presence HMTETA. Moreover, higher reactivity of PEOMA than OPOPhNA (r(methacrylate) > r(acrylate)), which was observed during copolymerization, suggested the formation of copolymers with a spontaneous gradient composition starting from the grafted segment of P(PEOMA). The molecular weight distribution (MWD) was increased with DP in the range 1.2-1.6. The X-ray diffraction analysis (WAXS) indicated that larger number of PEO segments generated crystalline properties in the copolymers with amorphous OPOPhNA. (c) 2007 Elsevier Ltd. All rights reserved.