Graft Copolymerization of Vinyl Monomers on Modified Cotton

Abstract

The interaction of acrylonitrile and methyl methacrylate with cellulose crosslinked in either the wet or dry state under the catalytic influence of Ce^IV ions has been investigated. It was found that the graft yields obtained with dry cross linked cellulose are much lower than those of the control, whereas the yields obtained with wet crosslinked cellulose and the control are comparable. Dry crosslinking prior to grafting seems to cause a significant structural change, particularly in the disordered regions, reducing the accessibility of these regions to grafting. Wet crosslinking, on the other hand, appears to stabilize the uncollapsed state of the cellulose thereby leaving its susceptibility toward grafting practically unaltered. The consumption of Ce^IV during grafting is higher than that during oxidation, probably due to homopolymer formation. This is observed with the crosslinked celluloses as well as with the controls. The Ce^IV consumption during oxidation of crosslinked cellulose is comparable with that of the controls regardless of the crosslinking method. The bound formaldehyde in crosslinked cellulose decreases after Ce^IV treatment, indicating some cleavage of the crosslinks.