A process for the manufacture of maleated polypropylenes having an acid number greater than 6, a yellowness index color of no greater than 76, and a number average molecular weight of at least 20,000. The process for making the maleated polypropylenes includes forming a mixture of molten polypropylene and molten maleic anhydride in a reactor, introducing a free radical initiator into the molten mixture to produce a product having maleic anhydride grafted onto the polypropylene, and recovering a high acid number, high molecular weight maleated polypropylene of low color from the reactor.