Biochar-thermoplastic Polymer Composites: Recent Advances and Perspectives

To fulfill the current circular economy concept, several attempts to reuse and valorize wastes and by-products coming from different sectors (such as the agri-food, textile, and packaging industries, among others) are being carried out at least at a lab scale by academics, despite the increasing interest that also involves the industrial world. One of the up-to-date strategies to transform wastes and by-products into new added-value systems refers to the production of biochar (BC), a carbonaceous solid residue derived from the thermo-chemical conversion, under controlled conditions, of wastes or, more generally, biomasses. Apart from its conventional uses (such as for soil remediation, heat and power production, low-cost carbon sequestration, and as a natural adsorbent, among others), BC is gaining a continuously increasing interest as a multifunctional micro-filler for different thermoplastic and thermosetting polymer matrices. Undoubtedly, the wide possibility of producing BC from different biomass sources, wastes, and by-products offers an attractive prospect toward a circular bioeconomy with “zero waste”. When incorporated into a polymer at different loadings, BC can provide thermal and electrical conductivity, EMI shielding features, enhanced mechanical properties, and flame retardance as well. This chapter aims to summarize the current achievements in the design, preparation, and characterization of thermoplastic polymer/biochar composites, discussing the current limitations/ drawbacks, and providing the reader with some perspectives for the future. 

Keywords: Biochar, Degree of Graphitization, Electrical Conductivity, EMI Shielding, Flame Retardance, Mechanical Behavior, Thermoplastic-biochar Composites, Thermal Conductivity