Quantitative analysis on the grafting of an aromatic group on polypropylene in melt by FTIR technique

The FTIR quantitative analytical method is described as an alternative technique for determination of percentages of grafted content in the grafting of an aromatic group on polypropylene. An aromatic vinyl monomer (designated SG1) was grafted onto a commercial isotactic polypropylene (PP) by an organic peroxide (Trigonox 101). Dried extracted samples were evaluated using FTIR qualitative and quantitative analytical methods. The grafting reaction was confirmed through FTIR spectra showing infrared bands which conformed to aromatic substituted benzene in the grafted copolymer. Weight percentage of monomer grafted to polypropylene and percentage grafting of monomer were obtained from computer-plotted regression curves. These values obtained by an FTIR quantitative analytical method through the measurements of infrared absorbance bands of grafted polymer (PP-g-SG1) at two different peaks (752 cm −1 and 690 cm −1), before and after extraction, were found to be consistent.