POLY 39 |
| The graft copolymerization of methylmethacrylate (MMA) on cellulose (Cell) was carried out using CuBr / bipy and FeCl3 / PPh3 as catalyst in atom transfer radical polymerization (ATRP) and reverse atom transfer radical polymerization (RATRP) in DMF at 50 0C. The cellulose bromide (Cell-Br) and azobisisobutyronitrile (AIBN) were used as initiators in these polymerization reactions. The effect of these catalysts was evaluated on molecular weight and its molecular weight dispersity of grafted polymethylmethacrylate chains. The molecular weight (MW) and its dispersity were improved in presence of these catalysts in comparison to catalyst used in conventional radical polymerization processes. The RATRP process in graft copolymerization of MMA was more precise in molecular weight and molecular weight distribution than ATRP process. The conversion of MMA in graft copolymerization was more in RATRP process but ATRP process has relatively produced more ungrafted PMMA. The graft copolymerization of MMA in both processes has followed first order kinetics and increased significantly with the increase in reaction temperature. The energy of activation was low (42 kJ mol-1) in RATRP process than ATRP process (48 kJ mol-1). The i.r. and thermal techniques of analysis were used as evidence for graft copolymerization of PMMA on cellulose. The effect of dielectric constant of the medium was analyzed by studying the graft copolymerization of MMA in toluene |
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General Papers: Functional Materials
8:00 AM-12:00 PM, Sunday, August 19, 2007 Westin Boston Waterfront -- Douglas, Oral
Division of Polymer Chemistry |