Evaluation of the influence of the use of waste from the processing of rice in physicochemical properties and biodegradability of PHB in composites

Abstract

The high calorific value of rice husks has elevated its reuse as an energy source; however, the burning of these shells generates a waste ash from rice husk ash (RHA), which makes its disposal a concern. Despite advances, biodegradable polymers are not yet able to compete with those of traditional thermoplastics, which have lower production cost and higher performance. Based on this background, this paper studies the feasibility of reuse of RHA as filler in polymer matrices replacing the conventional filler. This study consists of applying different percentages of RHA in the formulation of polyhydroxybutyrate composite (PHB) and the use of talc (TA) for comparison purposes as conventional filler. The composites used in this assay were obtained by twin-screw extrusion and injection molding of the polymer plus the fillers under study. Physicochemical and biodegradability properties of the composites were evaluated. The composite PHB/RHA was superior in the biodegradability tests and the properties remain practically unchanged in the presence of the filler. Thus, composites with RHA are promising because they take an abundant residue combined with degradation capacity of the polymer, therefore reducing cost and the environmental impact.

Keywords

• Rice husk ash
• composites
• PHB
• talc
• fillers