An immobilized/soluble hybrid catalyst system for atom transfer radical polymerization

A new two-component catalyst system consisting of an immobilized catalyst a nd a soluble catalyst in ppm quantities was applied to atom transfer radica l polymerization (ATRP). A high conversion of monomer (>90%) was achieved w ith a predetermined molecular weight and narrow molecular weight distributi on (M-w/M-n = 1.1-1.3) in the ATRP of methyl methacrylate and methyl acryla te. The immobilized catalyst was removed by a filtration or sedimentation p rocedure. The casting of the reaction solution afforded clear and colorless polymer films. It was confirmed by the inductively coupled plasma (ICP) an alysis that the residual amount of Cu in the resulting polymer was as low a s 20 ppm.