Grafting on crosslinked polymer beads by ATRP from polymer supported N-chlorosulfonamides

Grafting of methyl methacrylate (MMA) and ethyl acrylate (EA) monomers from immobilized N-chlorosulfonamide (NCSA) groups on crosslinked polystyrene-based beads have been achieved by copper mediated atom transfer radical polymerisation (ATRP) methodology. The initiation takes place via NCSA groups on the polymer, created by chlorination of crosslinked polystyrene sulfonamides. Using CuBr and hexacishexyl triethylenetetramine ligand for MMA and EA grafting showed a first order kinetics for each monomers. Polymers with 3.18 mmol g^-1 of NCSA groups have a progressive mass increase in accordance with increasing MMA graft polymerisation up to 380.0% grafting obtained after 6 h. By the method presented, grafting of MMA and EA have been successfully achieved with negligible amounts of free polymer formation (6.2%) in the solution. Hence grafting by ATRP through polymer supported NCSA is superior to the common radical grafting methods which are yielding free polymers simultaneously. The method provides an efficient procedure in preparing core-shell type of polymers, with retention of the bead shapes.