Synthesis and charcterization of diblock copolymers containaing monothio-orthoester functions using raft polymerization
The acyclic and cyclic monothio-orthoester monomers were synthesized by modification of aromatic monomers containing dithioester function in the side chain. Reversible addition-fragmentation chain transfer (RAFT) polymerization was employed for the preparation of polymers containing a dithioester end as macro-chain transfer agents (macro-CTA) using 4-benzyl methyldithiobenzoate (BMDTB) as chain transfer agent (CTA) and 2,2-azobisisobutyronitrile (AIBN) as initiator. A series of diblock copolymers were prepared by RAFT copolymerization of MVDTB, MMMS and MVPOCO, using the different macro-chain transfer agents (macro-CTA) and AIBN as initiator. All polymerizations were carried out at 60 °C for 24 or 30 hours in dry THF. Homopolymers and diblock copolymers are characterized by 1H NMR, 13C NMR, IR, SEC, DSC and TGA.
Keywords: Dithioesters, monothio-orthoesters, RAFT polymerization.