Aspects of Thermal Graft Copolymerization of Methyl Methacrylate onto Ethyl Cellulose in Homogeneous Media

Abstract

Abstract Homogeneous graft copolymerization of methyl methacrylate (MMA) onto ethyl cellulose (EC) using radical initiators such as ammonium persulfate (APS), potassium persulfate (KPS), and benzoyl peroxide (BPO) was carried out in benzene/DMSO (1/1 v/v) mixed-solvent system. The grafting yield (GY%) was determined as functions of the polymerization temperature and of the concentrations of a monomer, ethyl cellulose, and an initiator. Several techniques were used for confirming the presence of PMMA-grafted chains such as IR, TLC, and NMR. The efficiency of grafting MMA onto EC with APS and KPS was studied in different solvent systems. So, the power of solvents for increasing the grafting yield was found as follows: chloroform > toluene > benzene. The highest overall rates for copolymerization of MMA onto EC using APS and KPS initiators were determined as 0.2% min-1 and 0.08% min-1, respectively. BPO was found to be an unsuitable initiator for grafting MMA onto EC. A Trommsdorf effect was observed in some systems. The mechanism of grafting reaction of MMA onto EC is discussed.