Polypropylene having high maleic anhydride content, between about 5 and about 45 wt %, may be prepared by first reacting a metallocene-prepared polypropylene having terminal unsaturation with one mole equivalent of maleic anhydride to give polypropylene having a single unsaturation and a terminal succinic anhydride moiety. This product is then reacted with additional maleic anhydride in the presence of a free radical initiator (such as a peroxide or UV radiation) to give a polypropylene with maleic anhydride moieties along the backbone. The polypropylene product does not suffer scission or crosslinking with subsequently undesirable increases in molecular weight or viscosity. The maleic anhydride moieties provide reactivity to the polypropylene and thus expand its uses and applications.