Grafting onto cellulose. VIII. Graft copolymerization of poly(ethylacrylate) onto cellulose by use of redox initiators. Comparison of initiator reactivities

In an attempt to compare the relative reactivities of different redox systems in graft copolymerization of vinyl monomers onto cellulose, we studied grafting of ethylacrylate (EA) in aqueous medium by using the well-known redox intiator, ferrous ammonium sulfate–potassium persulfate (FAS–KPS) system, and its reactivity was compared with that of Fenton's reagent (Fe²⁺ ?H₂O₂) towards grafting of EA onto cellulose. Optimum conditions for affording maximum grafting were evaluated and percent grafting is expressed as functions of different reaction variables. Evidence of grafting was obtained from IR spectroscopic measurements, SEM, and TGA studies of the grafted and ungrafted cellulose. A plausible explanation for the observed reactivity pattern shown by (FAS–KPS) and (FAS–H₂O₂) redox systems is offered. Fenton's reagent (Fe²⁺ ?H₂O₂) was found to be several times more reactive than (FAS–KPS) redox system.