Graft copolymerization of glycidyl methacrylate onto delignified kenaf fibers through pre-irradiation technique

•We used kenaf fibers for radiation induce graft copolymerization with GMA.•Kenaf fibers was treated to remove lignin in order to increase grafting yield.•Treated kenaf fibers were graft copolymerize through preirradiation technique.•Optimum conditions for graft copolymerization of kenaf fibers were established.•Formation of graft copolymer is also confirmed with SEM, FTIR and XRD.

Glycidyl methacrylate grafted kenaf (GMA-g-Kenaf) was prepared by pre-irradiation grafting technique. Kenaf fibers were treated with different concentration of sodium chlorite solution before used as trunk polymer. Treated kenaf fibers were irradiated by electron beam followed by grafting reaction in GMA/water emulsion system. The degree of grafting was determined as a function of absorbed dose, reaction time, reaction temperature and concentration of monomer. The results showed that the lignin content was decreased from 14.3% to as low as 3.3% with the increased of sodium chlorite concentration. This was evidenced by SEM pictures which show the surface of treated kenaf fibers was cleaner and smoother compared to that of untreated one. The degree of grafting increased with the increase of absorbed dose, reaction temperature, reaction time and monomer concentration as well as with decreasing lignin content. Formation of graft copolymer was confirmed with SEM, FTIR analysis. The structural investigation by XRD showed that degree of crystallinity of graft copolymers decreased with the increase in degree of grafting.