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

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• 作者：Kun Jiang ; Chunnuan Ye ; Peipei Zhang ; Xiaosong Wang ; Youliang Zhao
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：February 14, 2012
• 年：2012
• 卷：45
• 期：3
• 页码：1346-1355
• 全文大小：485K
• 年卷期：v.45,no.3(February 14, 2012)
• ISSN：1520-5835

文摘

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鈥?/i>-3-(trimethoxysilyl)propyltrithiocarbonate (MPTT) and R-functionalized S-4-(trimethoxysilyl)benzyl S鈥?/i>-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鈥?20 渭mol/g as the molecular weights of grafted polymers were in the range of 3980鈥?2500 g/mol. The improved solubility and dispersibility of GO鈥損olymer composites in various solvents comprising hexane and water confirmed their amphiphilicity. The grafting process offers an opportunity to alter GO morphologies, and surface morphologies involving nanosheets, nanoparticles, and nanorods were observed as the composites were dispersed in different solvents with the aid of sonication treatment. This tandem approach is promising for surface modification of solid substrates with hydroxyl surface due to its mild conditions, straightforward synthesis and good controllability.