Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate) Produced from Food-Related Wastes: Solid-State NMR Analysis

Poly(hydroxyalkanoates) (PHAs) have garnered significant attention due to their biodegradable and biocompatible properties, making them promising alternatives to conventional petroleum-based plastics. As microbial-derived polyesters, PHAs offer a sustainable solution to plastic waste accumulation and microplastics because they can be produced from renewable resources, including food-related waste. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a copolymer in the PHA family, exhibits improved mechanical flexibility and thermal properties compared to poly(3-hydroxybutyrate), thereby broadening its potential applications. In this work, eight samples of PHBV, including those made from food waste and municipal waste streams, were studied by solid-state NMR. Information obtained includes the copolymer composition, chemical shifts due to crystalline lattices, crystallinity, and polymer chain mobility. The composition matches the results from the fatty acid feed and solution NMR analysis. The samples appear to be about 62–70% crystalline. No significant differences in mobility are observed from NMR relaxation data. These results indicate that PHBV materials generated from different food-related waste sources, despite their compositional differences, possess similar crystallinity and molecular mobility, suggesting their suitability as biobased semi-crystalline plastics.