Surface analysis of grafted low density polyethylene film by FTIR and XPS spectroscopy

Abstract

This paper studied the alternative method for determination of percentage of grafted content in the grafted low density polyethylene (LDPE) film with black seed oil (BSO). BSO was grafted onto LDPE by pre-irradiation grafting method and the grafted samples were evaluated using FTIR qualitative and quantitative analysis. The grafting yield was calculated quantitatively from absorbance peak of two difference peak (1464cm-1 and 1746cm-1 ). Control LDPE film shows no absorbance peak at wavenumber of 1746cm-1 while, a peak appears for grafted film at the same wavenumber. Therefore, it is possible to consider the peak area in this wavenumber as the grafting extension of BSO in LDPE film. Meanwhile, concerning the infrared (IR) fingerprint of LDPE film, consistent peak characteristic bands of LDPE are also present for all grafted sample at 1464cm-1 . Thus, the grafting yield is computed by using these peaks. Then, further confirmation grafting of BSO onto LDPE film was supported by the XPS spectroscopy. The atomic composition of C decreased 13% after LDPE film was grafted with BSO. While the O content increases from values of 6.9% to 19.2% after grafting reaction. The increment percentage of O1s after grafting reaction mainly caused by the incorporation of oxygen content of a new polar functional groups of BSO on the surface of LDPE films. These results are in good agreement with FTIR analysis.