A Silicone-Based Macro-Initiator for RAFT Polymerization

Reversible addition-fragmentation chain transfer (RAFT) polymerization is an efficient technique for synthesis of polymers with well-defined architecture. Here, a macro-initiator based on dihydroxy-terminated polydimethylsiloxane (PDMS) and 4-Cyano-4-(phenylcar-bonothioylthio) pentanoic acid as a chain transfer agent (PDMS-macro CTA) were prepared via esterification reaction promoted in the presence of dicyclohexylcarbodiimide (DCC) coupling agent and 4-(dimethylamino) pyridine (DMAP) as a catalyst. PDMS-macro CTA was purified and characterized by FTIR spectroscopy. According to the FTIR findings, absence of hydroxyl functional groups, a broad peak in the region of 3340 cm⁻¹ and appearance of carbonyl ester groups at 1743 cm⁻¹ supported the performance of the esterification reaction.