Grafting yield determination of glycidyl methacrylate vapor on radiated kenaf fiber via FTIR spectroscopy

Abstract

In this study, glycidyl methacrylate (GMA) was grafted onto kenaf fiber using radiation-induced graft polymerization technique in vapor phase. The pre-irradiation of kenaf fiber was carried out at different doses from electron beam accelerator at various absorbed radiation doses (10 to 100 kGy). The grafting process was carried out in a vapor-phase graft polymerization reactor operated at temperature of 40 °C. The grafted chains were verified with FT-IR spectroscopy analysis. The percentage of grafting, Pg (%) of the grafted kenaf fiber was calculated based on quantitative Fourier transform infra-red spectroscopy (FTIR) analysis. Functional group present onto the kenaf fiber backbone after grafting was used to quantify the unknown amount of GMA grafted to the kenaf fiber and to calculate the Pg (%). Characteristic peak of 1725 cm-1 corresponding to the carbonyl group of GMA was chosen for calibration purpose in order to derive a linear regression plot of peak area versus the weight per volume percent of GMA (w/v%). The correlation coefficient for the calibration line is 0.967, which indicates that the correlation between absorbance and concentration is good. It was observed that grafting of vapor GMA onto pre-irradiated kenaf fiber reach the maximum yield of 191.89% with the absorbed radiation dose of 50 kGy.