Development of Compatibilized Polyamide 1010/Coconut Fibers Composites by Reactive Extrusion with Modified Linseed Oil and Multi-functional Petroleum Derived Compatibilizers

This work reports the preparation and characterization of fully bio-based polymer composites with coconut fibers (CFs) as an alternative to wood-plastic composites (WPCs), typically based on petroleum derived materials. Polyamide 1010 (PA1010) was melt-extruded with 20 wt% of CFs and, after that, shaped into pieces by injection molding. Four different multi-functionalized compatibilizers were tested to increase the polymer-fiber interactions with the subsequent improvement on toughness. These consisted of two chemically modified vegetable oils, namely maleinized and epoxidized linseed oil (MLO and ELO) respectively, and two commercial additives derived from petroleum and based on glycidyl functionality, that is, low-functionality epoxy-based styrene-acrylic oligomer (ESAO) and polystyrene-glycidyl methacrylate random copolymer (PS-GMA). The addition of all four compatibilizers improved both the mechanical and thermomechanical properties of the composites, thus resulting in high-performance composite materials with relatively low water uptake. Furthermore, the morphology of the obtained composites revealed an extraordinary embedment of the fibers into the biopolymer matrix, which plays a crucial role in improving toughness. Among all the tested compatibilizers, those derived from vegetable oils can be considered the most interesting ones due to they offer a more sustainable solution.