Studies on the Preparation of Telechelic Polymers by Atom Transfer Radical Polymerization and Cross Coupling Processes

Combination of Atom Transfer Radical Polymerization (ATRP) and Atom Transfer Radical Cross Coupling (ATRCC) processes as a route to prepare telechelic polymers was described. The concept is based on the activation of the dormant species at the chain ends of polystyrene (Br-PS-Br or PS-Br) prepared by ATRP and functional ATRP initiator (F-R-Br) in the absence of a monomer. Depending on the type of polystyrene used in the system, cross coupling of these active species gives α,ω-polystyrene and ω-polystyrene telechelics. Detailed investigations using a model system revealed that the efficiency of functionalization was not very high because of the self-coupling of the species derived from the polymer and functional initiator. However, the highest functionalization (Xf=0.85) was achieved by introducing a small amount of styrene in the ATRCC.