In this report, melt grafting of maleic anhydride (MAH) and epoxy resin onto polypropylene (PP) by peroxide-initiated reactive extrusion has been investigated. As evidenced by Fourier transform infrared spectroscopy, both MAH and epoxy resin were successfully grafted onto PP through the reactions of MAH with PP and epoxy resin with MAH. It was found that tetramethyl thiuram disulfide could promote the grafting of MAH and inhibit the degradation of PP, as revealed by chemical titration and melt flow experiments, through prolonging the lifetime of the macroradical; meanwhile, epoxy resin could reduce the sublimation of MAH and the maximum grafting degree of MAH. Furthermore, the introduction of grafted products was found to enhance the mechanical properties of PP/glass fiber composites, and this influence was very significant at high grafting degrees with a high content of epoxy resin, which could be interpreted in terms of improved compatibility and adhesion at the interface.
High melt strength polypropylene was successfully prepared by a reactive extrusion method, in which pure polypropylene without any additives was used as a basic resin; trimethylolpropane triacrylate was used as a grafting monomer, and styrene and zinc dimethyldithiocarbamate (ZDMC) were used as trapping radicals. The synergistic effects of styrene and ZDMC on melt strength and melt flow rate of modified polypropylene were investigated. When the additions of styrene and ZDMC were 3.5 parts by weight per hundred parts of resin (phr) and 0.3 phr, respectively, the melt strength of modified polypropylene (PP5) was about 21 cN, which was much higher than that of modified polypropylene without styrene (PP0, 4.6 cN). Moreover, crystallization behavior and mechanical properties of modified polypropylene were also investigated. The results showed that the melt and crystallization temperatures of modified polypropylene with styrene were higher than those without styrene, and the size of crystal was smaller. Moreover, the mechanical properties of modified polypropylene were greatly improved in the presence of styrene. J. VINYL ADDIT. TECHNOL., 00:000-000, 2015.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.