Amir Rostami - Department of Polymer Engineering, Amirkabir University of Technology, Mahshahr campus-Mahshahr-Iran
Mohammad Reza Maleki Sede - Department of Polymer Engineering, Amirkabir University of Technology, Mahshahr campus-Mahshahr-Iran
Hamid Garmabi - Department of Polymer Engineering and Color Technology, Amirkabir University of Technology-Tehran-Iran

In this study, styrene as a reactive comonomer, dicumyl peroxide (DCP) as an initiator and monomer glycidyl methacrylate (GMA) as a modifier were used to investigate the melt free radical grafting of the GMA onto polypropylene (PP) in a co-rotating twin screw extruder. The characteristics of the GMA-grafted samples in the presence and absence of styrene, different styrene concentrations, different GMA concentrations and different DCP concentrations were examined and compared in terms of the grafting degree using titration/back-titration technique and Fourier transform infrared spectroscopy (FTIR). In the absence of the styrene, GMA-grafting levels were found to be low and high DCP concentrations were required to achieve the higher grafting degrees. Concomitantly, grafting degrees increased with increasing DCP concentrations because of enhanced chain scission. Presence of a small amount of styrene causes a significant increase in the grafting degree. It was shown when the styrene concentration was taken equal to the GMA concentration, where the grafting degree was highest.

Polypropylene, Free-radical grafting, Glycidyl methacrylate, Grafting degree