Manufacturing, characterization and accelerated weathering of biocomposite made of poly (β-hydroxybutyrate)-co-poly(β-hydroxyvalerate) and non-woven alfa fibers

This article investigates the feasibility of manufacturing a biocomposite composed of a biopolymer, poly (β-hydroxybutyrate-co-β-hydroxyvalerate) (PHBV), reinforced with cellulose nonwoven Alfa fibers. To better understand the behavior of this composite, accelerated weathering tests were conducted. To simulate extreme environmental conditions, composite samples were exposed to cyclic ultraviolet (UV) light, water spray, heat, and high relative humidity. The tensile and physical properties (mass and cross-sectional dimensions) of the composites were evaluated throughout the aging process. Changes in elastic modulus, stress, strain, as well as mass, width, and thickness were recorded. The study revealed the effects of accelerated weathering on PHBV–Alfa composites. Overall, the samples exhibited a relative decrease in physical and mechanical properties, except for the elastic modulus, which showed a slight increase toward the end of the test. Furthermore, the main degradation mechanisms responsible for the observed property reductions were identified as photolysis, hydrolysis, and photooxidation of the polymer surface, along with fiber–matrix interface deterioration caused by swelling of Alfa cellulosic fibers.