Rheology, Morphology, and Mechanical Performance of Polypropylene/Recycled Fishing‐Net Polyamide 6 Blends Modified With MAH ‐ PP and ADR and Their Long Glass‐Fiber Thermoplastics

This study investigates the use of recycled polyamide 6 (rPA6) from discarded fishing nets as a matrix material for automotive reinforced composites, targeting marine pollution reduction and compliance with increased recycled content. In processing long fiber‐reinforced thermoplastics (LFT), polypropylene (PP) was incorporated to improve the flow of high‐viscosity rPA6 and manage the hygroscopic nature of PA6. To achieve compatibility between the immiscible polymers, maleic‐anhydride‐grafted PP (MAH‐PP) was introduced. An epoxy‐functional chain extender (Joncryl ADR, ADR) improved interfacial bonding with glass fiber, yielding effective PP/rPA6 LFT composites. The microstructural evolution was characterized using rotational rheometry and FE‐SEM, and tensile and impact tests evaluated fiber–matrix adhesion. Adding 9 wt% MAH‐PP improved compatibility via PP‐g‐PA6 formation, decreasing interfacial tension while enhancing storage modulus and complex viscosity at low frequency. The introduction of MAH‐PP reduced PA6 domain size within the PP matrix, correlating with superior mechanical performance, notably in tensile properties. This formulation enabled the fabrication of LFT pellets with improved processability and mechanical attributes, establishing clearer structure–property correlations and highlighting the suitability of fishing‐net‐derived rPA6 for automotive applications in conventional processing.