Improvements of polypropylene grafted maleic anhydride with ultrasonication, pre-irradiation and co-irradiation methods

This paper presented many improvements of polypropylene (PP) grafted maleic anhydride (MAH), including how to increase graft degree (G) and graft efficiency (G _E ) of MAH onto PP and how to reduce side reactions during grafting. Three grafting methods ultrasonication, pre-irradiation and co-irradiation were employed, and a lot of additives were adopted in our research, such as styrene (St), ethyl benzoate, dibutyl phthalate (DBP), 2,2′-bipyridine, divinylbenzene (DVB), benzoyl peroxide (BPO) and p-hydroquinone. The effects of the different grafting methods and additives were determined by G and G _E values, viscosity, FTIR and DSC. Experimental results showed that the highest G value was obtained in co-irradiation method in the presence of St, and side reactions could be also reduced. The best reflux time for G value measuring, the storage time on G and batch feeding times of MAH on G in pre-irradiation method, and the mechanism of PP grafted MAH were all studied.