Styrene-assisted grafting of maleic anhydride onto polypropylene by reactive processing

Abstract

The grafting of maleic anhydride (MA) onto polypropylene (PP) was performed in the presence of the electron-donating monomer styrene (ST) according to a central composite experimental design, in which the initial MA and ST concentrations were varied. The grafting of MA onto PP in the absence of ST was also performed. All reactions were carried out in the molten state in a Haake rheometer. The amount of reacted MA and the extent of degradation in PP were determined by means of Fourier transform infrared spectroscopy and melt flow index (MFI) measure-ments, respectively. The results showed that the presence of ST in the reactive processing caused a reduction in MFI and an increase in the level of reacted MA when the initial MA concentration equaled the initial ST concentration. An increase in the initial MA concentration presented distinct behavior that depended on the ST content. ©2007 Wiley Periodicals, Inc.