Grafting of acrylic monomers onto cellulose. Influence on fibre absorbency

Abstract

The objective of our study is to show the importance of the chemical modification, by grafting, of cellulose in order to get a material with an improved absorption and retention. Acrylic monomers, acrylic acid (AA) and acrylonitrile (AN) were grafted onto cellulose by using a free radical process initiated by cerie ions. Fibrous supports used were: a Kraft fluff pulp, rayon fibers and short cotton fibers. Major factors affecting graft co-polymerization of acrylonitrile and acrylic acid onto cellulose, (surface morphology, initiation process, reaction temperature) were studied. The water absorption capacities and grafting values of modified cellulose were also determined. The maximum grafting yield was obtained at room temperature by using a CAN initiation technique. Saline solution (0,9% NaCI) absorbency was also studied, due to the counter ion effect retention of 0,9% aqueous NaCl was about 70% of the water retention value. The grafting has been confirmed by infrared analysis through the apparition of characteristic strips of monomers on spectrum of grafted samples. The absorbency of the grafted samples is significantly higher than that observed for the native cellulose. Acrylic functions grafted onto cellulose, have otherwise, improved liquid retention of samples