THE EFFECTS OF MONOMER TO CELLULOSE RATIO ON THE SWELLING EFFICIENCY OF ACRYLIC ACID-G-CELLULOSE COPOLYMER

Graft copolymerization of acrylic acid onto cellulose fibres using potassium persulphate initiator was investigated in an aqueous medium. Bleached cellulose fibre samples were pretreated by steeping in an initiator – water mixture and the grafting was carried out using 0.2% initiator concentration, at the same temperature and time of treatment, but different monomer to cellulose ratios. The attachment of monomer on the grafted fibres was confirmed by FTIR analysis using KBr technique which indicated the changes that occurred both inside and on the surface of the grafted products. Grafting parameters including percentage polymerization, graft percentage and graft efficiency increased as the monomer to cellulose ratio was increased, even though the ratios have more influence on graft efficiency. Swelling study was carried out and from the results; swelling efficiencies of the grafted samples were several times higher than that of the ungrafted cellulose sample. It was found that monomer to cellulose ratio had significant effect on swelling efficiency, especially when the ratios were above 1.0:1.0.