Broadening the scope of functional groups accessible in aliphatic polycarbonates by the introduction of RAFT initiating sites

Abstract

An approach to enlarge the range of functional cyclic carbonates by introducing a reversible addition-fragmentation chain transfer (RAFT) agent either as initiator or monomer was presented. After a 1 hr reaction time, a well-defined PLLA macroinitiator was obtained with retention of the trithiocarbonate group. The results show that a decrease in initial monomer concentration from 2 to 1 mol L -1 produces well-defined and narrowly dispersed copolymers. Comparing gel permeation chromatography (GPC) traces from the refractive index (RI) with UV-vis detectors demonstrates the complete incorporation of the 4-pyrene-1-butanol initiator in the polymer chain and the narrow molecular weight distribution. The results also show a conservation of 94% obtained from the relative intensity of acrylate protons at 5.5 ppm and amide methie protons from the repetitive units at 3.9 ppm.