Functionalization of Polyolefins with Maleic Anhydride by Flash Reactive Extrusion: Processing and Applications

Chemical modification of polyolefins, specifically polyethylene-containing resins, was carried out using an innovative process called "flash reactive extrusion" to produce polyolefins grafted with maleic anhydride (MA), circumventing the use of peroxide initiation. By variation of the appropriate processing parameters, polyolefins with high grafted maleic anhydride content and controlled viscosity (melt flow rate) were obtained. The resulting grafted polyolefins were then used as efficient compatibilizers in polyamide/polyolefin blends. It has been demonstrated that the use of a low molar mass PE-g-MA (Mn = 10000 g/mol) improved mechanical properties of PE/PA (50/50) blends. The control of both the molar mass and the MA grafting content ensured a sufficient entanglement regime while allowing a diffusion of PE-g-MA at the PE/PA blend interface when using a high concentration of PE-g-MA. This "flash reactive extrusion" for the production of MA grafted polyolefins offers a new strategy for the chemical valorization of polyolefin-based wastes.