Effect of ligno-derivatives on thermal properties and degradation behaviour of poly(3-hydroxybutyrate)-based biocomposites

Rice husk lignin was isolated by means of acidolytic (AL) or alkaline enzymatic extraction method. Biocomposites of poly(3-hydroxybutyrate) (PHB) and acetylated lignin were prepared by casting from chloroform solution. The morphological, structural and thermal characteristics of the biocomposites were extensively studied. The ligno-derivatives features, i.e. purity, chemical structure and molecular weight, influenced the thermal properties of the PHB-based biocomposites. The AL sample evidenced a marked interference on the crystallization behavior and thermo-oxidative degradation of the PHB. The decrease of PHB crystallization rate and the increase of thermal stability were observed as a function of the lignin amount in PHB-AL biocomposite series.