Synthesis of PMMA-b-PEG-b- PMMA by controlled Polymerization Using Macro-RAFT Agents

In this work controlled radical polymerization (CRP) of methyl methacrylate was carried out in the presence of the Poly(ethylene glycol)(PEG) xanthate reversible addition fragmentation (RAFT) chain transfer agent designated as (CTA1) and (CTA2). Firstly, PEGs having different molecular weights (400 and 600 g/mol) were reacted KOH and CS2 and the terminated 4-chloro benzoyl chloride to obtain PEG-xathates. RAFT agent possessing PEG chain was used in the RAFT polymerization of MMA to yield PMMA-b-PEG-b-PMMA tri-block copolymers which can be used in various potential applications. With the gravimetric follow of the reaction, the control mechanism works well and the molecular weight has grown linearly. The structures of the synthesized macro RAFT agents and polymers were characterized by 1H-NMR, 13C-NMR and FT-IR spectroscopic methods.