Grafting onto Cellulose. VI. Graft Copolymerization of Vinyl Acetate by Use of Metal Chelates as Initiators

Abstract

Abstract Graft copolymerization of vinyl acetate (VAc) onto cellulose has been studied in an aqueous medium in the presence of Fe(acac)3, Al(acac)3, and Zn(acac)2 as initiators. Percentage of grafting has been determined as a function of concentration of initiators and monomer, reaction time, and temperature. The reactivities of different metal chelates toward grafting of VAc on cellulose have been determined and were found to follow the order: Zn(acac)2 > Al(acac)3 > Fe(acac)3. A plausible mechanism for grafting involving complex formation between metal chelates and vinyl monomer has been suggested. Several grafting experiments were carried out in presence of CCl4, CHCl3, CH3CH2CH2SH and Et3N. All these additives with the exception of Et3N were found to suppress grafting.