Preparation and characterization of poly(vinyl alcohol) biocomposites with microalgae ash

Gasification of microalgae feedstock generates mineral ash. In this work, raw ash is produced from lipid-extracted algal biomass of the Nannochloropsis salina strain. Prior to using it as filler for composite fabrication with poly(vinyl alcohol), raw ash (RASH) is activated with NaOH and surface modified with (3-aminopropyl)triethoxysilane. Surface modification of activated ash (PASH) significantly improves interfacial interaction between surface-modified ash (GASH) and polymer matrix. Higher ultimate tensile strength of PVA/GASH composites is recorded, compared with PVA/RASH and PVA/PASH. Young's modulus of biocomposites appears to increase proportionally to loading of the fillers. Thermal properties of polymeric materials of PVA with these ashes are stable. This is the first report to demonstrate the utilization of microalgal ash, the leftover after completed gasification of algal biomass, as an efficient filler for production of value-added polymeric materials. It is proposed that microalgal ash is capable of improving the economic feasibility of microalgae-based biorefinery. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43599.