Toward the production of bioblends for the automotive sector: Reuse of recycled polyamide 6,6 to prepare super-tough biopolyethylene

Plastics reuse is essential for promoting a sustainable future, especially by miti-gating environmental impacts. Recycled polyamide 66 (PA66r) was reused forthe produce biopolyethylene (BioPE)-based blends, aiming to obtain a super-tough material. Initially, a premix of PA66r with maleic anhydride-graftedethylene–propylene–diene (EPDM-MA) was obtained in an internal mixer.Subsequently, the BioPE/PA66r and BioPE/(PA66r/EPDM-MA) blends wereprocessed in a twin-screw extruder and injection molded. The rheological,mechanical, thermal, thermomechanical, structural, and morphological prop-erties were investigated. Torque rheometry indicated an increase in the viscos-ity of the BioPE/(PA66r/EPDM-MA) blends compared to BioPE/PA66r, whichwas confirmed by a reduction in the melt flow index (MFI). EPDM-MA pro-moted greater stability in BioPE/(PA66r/EPDM-MA) blends during processing,reducing the degradation rate and molecular weight loss. The BioPE/(PA66r/EPDM-MA) blend with the 70/(15/15)% composition exhibited super-toughbehavior, with 822.4 J/m impact strength and 233% elongation at break. Scan-ning electron microscopy indicated a fracture with high plastic deformation,elongated fibrils, and refined particles (0.64 μm), confirming the high tough-ness. Apparently, a core-shell morphology was formed, which favored main-taining tensile strength, Shore D hardness, and heat deflection temperaturecomparable to pure BioPE. The results indicate potential for application in theautomotive industry, contributing to reintroducing recycled material into the production chain