One-Pot Controlled Synthesis of Homopolymers and Diblock Copolymers Grafted Graphene Oxide Using Couplable RAFT Agents

An original strategy is presented to synthesize homopolymers and diblock copolymers grafted graphene oxide by simultaneous coupling reaction and RAFT process. Z-functionalized S-methoxycarbonylphenylmethyl S′-3-(trimethoxysilyl)propyltrithiocarbonate (MPTT) and R-functionalized S-4-(trimethoxysilyl)benzyl S′-propyltrithiocarbonate (TBPT) were used as couplable RAFT agents to prepare the target nanocomposites. Under similar conditions, MPTT-mediated grafting reaction was liable to afford grafted chains with shorter chain length, narrower molecular weight distribution and lower grafting density than TBPT-based reaction owing to increased shielding effect and different grafting process. The grafted polymers had nearly controlled molecular weight and polydispersity ranging between 1.11 and 1.38, and the apparent molar grafting ratio was estimated to be 73.6–220 μmol/g as the molecular weights of grafted polymers were in the range of 3980–12500 g/mol. The improved solubility and dispersibility of GO–polymer co...