Grafting of polyolefins with maleic anhydride: alchemy or technology?

Nowadays, the process of maleic anhydride (MA) grafting and the application of MA‐grafted polyolefins are viewed as mature technologies. The chemistry and technology of modifying apolar polyolefins with the polar and reactive MA either in solution or in the melt were already explored as far back as the 1950s. Commercial applications exploit the improved adhesion of polyolefins to polar materials, both at the macroscopic scale and on the microscopic scale. However, it is hardly recognised that, from a scientific point of view, grafting has still a strong resemblance to alchemy. Both process and application technologies have been developed in a trial and error fashion. Only in the last decade the structure of MA‐grafted polyolefins has been elucidated and attempts to “look” inside the extruder during grafting were only recently successful. The first steps towards the development of sound chemical models are currently made. An overview will be given of the progress made in the various areas mentioned.