Surface composition and morphology of poly(3-hydroxybutyrate) exposed to biodegradation

Injected samples of poly(3-hydroxybutyrate) (PHB) were exposed to biodegradation in simulated soil and then characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), roughness and weight loss. The decomposition medium was evaluated by measurements of pH, humidity and amounts of carbon and nitrogen. The weight loss test indicated a significant weight decrease with time, which was more intense in the first 3 months of biodegradation. The results obtained by means of XPS, SEM, DSC and roughness analyses suggested a possible layer-by-layer degradation process having a 3-month period. (C) 2008 Elsevier Ltd. All rights reserved.