Development and Characterization of Electrospun Biopapers of Poly(3-hydroxybutyrate-<i>co</i>-3-hydroxyvalerate) Derived from Cheese Whey with Varying 3-Hydroxyvalerate Contents

In the present study, three different newly developed copolymers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with 20, 40, and 60 mol % contents in 3-hydroxyvalerate (3HV) were produced by biotechnological process mixed microbial cultures (MMCs) using cheese whey (CW), a by-product from dairy industry, as feedstock. The CW-derived PHBV copolyesters first purified then processed solution electrospinning, yielding fibers approximately 2 ?m cross-section all cases. resultant electrospun mats were, thereafter, post-processed annealing at temperatures, below their maximum melting, selected according to 3HV content order obtain continuous films based on coalesced fibers, so-called biopapers. characterized terms morphology, crystallinity, mechanical barrier properties assess potential application food packaging. biopapers showed high contact transparency but slightly yellow color. 20 copolymer seen contain mostly poly(3-hydroxybutyrate) (PHB) crystals, 40 mixture PHB poly(3-hydroxyvalerate) (PHV) crystals lowest sample made PHV crystals. To understand interfiber coalesce undergone materials during annealing, crystalline morphology was also assessed variable-temperature both combined small-angle wide-angle X-ray scattering synchrotron Fourier transform infrared experiments. From these experiments and, previously reported lower contents, samples inferred have surface energy reduction mechanism for coalescence which is thought be activated temperature-induced decrease molecular order. Due reduced crystallinity order, biopapers, especially sample, found more ductile tougher. properties, performed similarly water limonene, oxygen, highest relative permeability. Overall, developed, are compatible Circular Bioeconomy organic recycling strategy, can an excellent interlayers or coatings interest