Characterization and Application in Biocomposites of Residual Microalgal Biomass Generated in Third Generation Biodiesel

This research paper provides a brief discussion about the relevance of third generation biodiesel co-products diversification. This diversification can be performed through the utilization of residual microalgal biomass (RMB) after oil extraction process. The present work analyses the use of RMB as potential filler for biocomposite production by means of understanding the chemical composition, the thermal stability as well as the protein content of RMB. Thermogravimetric analysis revealed the processing window of the RMB for biocomposite production and its dependence on its purity, especially on residual fat content. Biocomposites of RMB and poly(butylene succinate) (PBS) were prepared by melting processing technique using extrusion followed by injection-molding. Tensile, flexural and impact properties of the processed samples were evaluated. Scanning electron microscopy of fractured sections of the biocomposites was also used to examine the dispersion of RMB in PBS matrix. Finally, this study shows a competitive alternative to produce PBS-RMB biocomposites by replacing PBS by RMB in the range between 20 and 30 %. However, further studies are necessary to improve the compatibility of RMB with PBS to obtain competitive mechanical properties, compared to neat materials through, for instance, block co-polymers.