Optimizing Acrylonitrile Grafting onto Rayon Fibers to Enhance Its Application Characteristics

Rayon is a regenerated cellulosic fiber, extensively being used in biomedical applications in the form of fabrics and surgical dressings. As a surgical dressing material, rayon exhibits advantages including light in weight, swelling ability, retaining absorbency on storage, does not shed fibers on the surface of the wound while cleaning the wound etc. However, conventional rayon-based dressing materials exhibit restricted swelling capacity that need to be enhanced for better absorption of wound exudates and rapid wound healing. Further, the mechanical properties and anti-bacterial properties must be worked upon as moisture absorption hampers these properties. To overcome these challenges, the structure of rayon fibers can be tailored through functionalization to increase its swelling capacity and to widen their application such as for full thickness skin wound applications. In the present study, rayon fibers are grafted with acrylonitrile (AN) to provide Ry─g─AN (Rayon─grafted─acrylonitrile). The grafting is carried out under microwave radiation catalyzed by cerium ions. The structure and morphology of the prepared fibers are characterized by SEM, FTIR, and XRD. The grafting conditions are systematically studied, optimizing factors, including concentrations of initiator and AN, temperature, solvent etc. with respect to the variations in grafting percentage. Maximum grafting obtained is 178% with 4 ml of monomer concentration, 0.5 ml initiator concentration, 30 ml of solvent, and 3 min. of microwave radiation exposure. Acrylonitrile is one of the versatile monomers that can impart mechanical strength, antimicrobial properties, along with reactive nitrile groups that could assist in further chemical treatment and drug loading to the dressing material.