(409b) Anaerobic Degradation of Phbv/Wood Flour Biocomposites: Impact of Fiber/Matrix Compatibilization On End-of-Life

The development of bio-based polymers and composites with a closed-loop lifecycle has the potential to significantly improve the environmental impact of the construction industry by reducing construction and demolition debris, greenhouse gas emissions, and the consumption of fossil fuels used as a material feedstock. Poly(hydroxybutyrate-co-valerate) (PHBV) is a biodegradable polymer produced by bacteria, which can be blended with natural fibers to form a composite that is of interest for a variety of construction applications.  These materials can be anaerobically degraded at their end-of-life into a methane-rich biogas feedstock. This work explores how the material properties of the biocomposite, including modifications to the fiber or polymer fractions to optimize in-service properties, contribute to the degradation of the material at end-of-life.  Injection molded biocomposites comprised of PHBV polymer matrices with an oak wood flour (OWF) fiber content of 10wt%-40wt% were manufactured with untreated and silane-treated OWF, as well as neat and maleated PHBV in order to investigate the impact of fiber/matrix compatibilization on the biocomposites. Anaerobic digester sludge from wastewater treatment was used as the inoculum for the degradation studies.  Characterization of the biocomposites, including scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and results from X-ray scattering experiments prior to and during various degrees of degradation will be presented.  How the biocomposite material properties influence the rate and extent of anaerobic biodegradation will also be discussed.