The end-hydroxy groups of poly(ethylene glycol) methyl ether(MPEG) were converted into end-amino and end-isocyanate groups,respectively,by step reactions of MPEG with para-toluenesulfonamide and phthalimide potassiumand,and/or by the reaction of MPEG with diisocyanate.The graft reactions between polypropylene grafted maleic anhydride(MPP) and MPEG with different end groups were conducted in xylene,in order to prepare graft copolymer of polypropylene and polyethylene glycol(PP-g-PEG).FT-IR and 1H-NMR were used to characterize structure of the reaction products.It was found that the reactivity of the end-functional groups of MPEG in the reaction with MPP follows this order:-NCO>-NH2>-OH.For MPP/MPEG-NCO reaction system,reaction extent and PEG grafting ratio increase when the molar ratio of(NCO)/(anhydride) raises from 1∶1 to 5∶1.However,the reaction extent and the number of PEG chains grafted onto PP chains decrease when the molecular weight of MPEG increases from 1000 to 6000.