Polymer Bulletin, Vol.77, No.7, 3831-3851, 2020
RAFT polymerization of styrene mediated by naphthyl-functionalized trithiocarbonate RAFT agents
Three new naphthyl-functionalized trithiocarbonate RAFT agents, ethyl 1-naphthylmethyltrithiocarbonate, butyl 1-naphthylmethyltrithiocarbonate and dodecyl 1-naphthylmethyltrithiocarbonate, were prepared and employed as chain transfer agents in RAFT polymerization reactions. The RAFT polymerization of styrene, mediated by the different naphthyl-functionalized trithiocarbonate RAFT agents, with AIBN as the initiator at 75 degrees C proceeded via a controlled/living polymerization process to produce quantitative yields of alpha-naphthyl-functionalized polymers with the naphthyl group introduced at the alpha-terminus of the polymer chain. Ultraviolet visible spectroscopy and fluorescence spectroscopy data provide evidence for the incorporation of the naphthyl group at the alpha-terminus of the polymer chain. Polymer kinetic measurements show that each polymerization reaction follows first-order rate kinetics with respect to monomer consumption and the number average molecular weights increase linearly with monomer conversion to produce polymers with narrow molecular weight distributions. The percentage monomer conversion for each reaction was monitored by(1)H NMR spectroscopy. The naphthyl-functionalized trithiocarbonate chain transfer agents and the alpha-naphthyl-functionalized polymers were characterized by(1)H and(13)C NMR spectroscopy, FTIR spectroscopy, size exclusion chromatography, ultraviolet visible spectroscopy and fluorescence spectroscopy. Graphic abstract The AIBN-initiated RAFT polymerization of styrene, mediated by new alkyl 1-naphthylmethyltrithiocarbonate RAFT agents at 75 degrees C proceeded via controlled/living polymerization processes to produce quantitative yields of alpha-naphthyl-functionalized polymers with the naphthyl group introduced at the alpha-terminus of the polymer chain.
Keywords:RAFT polymerization;Naphthyl-functionalized trithiocarbonate RAFT agents;alpha-Naphthyl-functionalized polystyrene;Fluorescence spectroscopy