Accelerated Weathering and Composting of Poly(hydroxybutyrate‐ co ‐hydroxyvalerate)/Agave Fiber Biocomposites Compatibilized With Glycidyl Methacrylate

ABSTRACT

The production and applications of biodegradable polymers have increased as a more environmentally friendly alternative to petrochemical plastics. Polyhydroxyalkanoates (PHA) are promising biopolyesters with excellent mechanical properties, particularly poly(hydroxybutyrate‐ co ‐hydroxyvalerate) (PHBV). In this study, the compatibilization of PHBV with a coupling agent synthesized from glycidyl methacrylate grafted onto PHBV (GMA‐ g ‐PHBV) was evaluated using two processing methods: (1) melt‐blending of all components by extrusion and (2) chemical treatment of agave fibers followed by dry‐blending. In both cases, the final samples were molded via thermocompression for further mechanical and thermal characterization. In addition, the durability was assessed in an accelerated weathering chamber. The results showed that the compatibilizer enhanced the tensile and flexural strength for both methods by improving interfacial adhesion. However, exposure to weathering had a detrimental effect on the biocomposites, caused by chain scission and moisture‐driven interfacial degradation, although the presence of the compatibilizer partially mitigated these losses. In particular, the chemical treatment of fibers followed by dry‐blending provided superior protection against weathering and maintained higher tensile properties than the extruded samples, likely due to the preservation of the polymeric structure during solid‐state mixing. Finally, the addition of fiber increased disintegration during composting, whereas compatibilization did not affect the composting process.