(468c) Biochar in Biocomposite Uses

Biochar is a charcoal-like product of the pyrolysis of biomass, and is emerging as an important bio-based resource. Biochar is very rich in carbon, and has been used as a soil amendment due to its ability to increase soil fertility and water retention. Biochar and its pyrolysis co-products, bio-oil and syngas, are also being studied for their application in the biofuel industry. This study investigates the potential of biochar as a structural biomaterial; specifically as a filler material in nylon polymer biocomposites. Composites were prepared from nylon-6 polymer and wood-based biochar using a twin-screw micro compounder and injection moulding. The biochar was used in its raw state (as-received from the manufacturer) and no compatibilizers were used in the composite. A range of processing and moulding temperatures, durations and pressures were used to optimize the quality of the processed composite material. The produced material was characterized through several different methods. Tensile, flexural and impact testing was used to analyze its mechanical properties. The melt flow index was analyzed for various loadings of biochar. The thermal behaviour of the material was also studied, including the coefficient of thermal expansion as well as the thermal conductivity. Scanning electron microscopy (SEM) was used to analyze the microstructure characteristics of the composite fracture surfaces. The study found that the unmodified biochar was not very compatible with the nylon-6, as the analyses showed that there was poor interfacial adhesion between the polymer matrix and the biochar particles. The biochar was also only able to be fully incorporated by the nylon matrix in relatively low loadings (under 15%). Future studies will investigate the modification of the biochar material with the goal of increasing interfacial adhesion and interaction with the nylon matrix.

Acknowledgements: The authors are thankful to the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph Research Program under Product Development and Enhancement through Value Chains Research Theme and the Ministry of Economic Development and Innovation (MEDI), Ontario Research Fund - Research Excellence Round 4 program, for their financial support to carry out this research.