Synthesis of Star Poly(N-vinylcarbazole) by Microwave-Assisted Reversible Addition-Fragmentation Chain Transfer Polymerization (RAFT)

Controlled radical polymerization of N-vinylcarbazole (NVK) via microwave-assisted reversible addition-fragmentation chain transfer (RAFT) polymerization is described. As chain transfer agent, 1,3,5-benzyl tri (diethyldithiocarbamate), was used. The chain transfer agent, containing a 1.3.5-trisubstituted benzene ring as core and three dithiocarbamate functionalities attached through an intermediate for fragmenting covalent bonds, led to poly(N-vinylcarbazole) (PVK) with star architecture. Polymerizations were carried out in 1,4-dioxane as solvent, at 70 degrees C, and studied for different polymerization times and monomer/CTA/initiator ratios. The SEC molecular weight curves exhibit a trimodal distribution, assigned to the linear and star-star coupling polymers, accompanying the real star polymer (as main product).