Pyrolyzed biomass from corn ethanol industry coproduct and their polypropylene-based composites: Effect of heat treatment temperature on performance of the biocomposites

This study targets the value-added engineering applications of Distillers? dried grains with solubles (DDGS), a coproduct from corn ethanol industry in lightweight biocomposites. The DDGS derived carbonaceous materials produced through torrefaction and pyrolysis were used as fillers for the manufacture of polypropylene (PP) based biocomposites. A systematic study was conducted for the first time in scientific literature in which the DDGS was heat treated from 100 to 1000 ?C (torrefaction; 200?300 ?C and pyrolysis; 400?1000 ?C) and used in the biocomposites with a fixed 30 wt % content. With increase in temperature of pyrolysis, the functional groups of the filler were removed, and the ash content was increased. The biocomposites showed their best performance in terms of stiffness-toughness balance with biocarbon pyrolyzed at 700 ?C, because of its non-polarity compared to the DDGS_400 ?C, and lower ash content and particle size than the DDGS_1000 ?C. Comparatively improved compatibility between the DDGS_700 ?C and PP resulted in higher complex viscosity and storage modulus than the rest of biocomposites. Overall, this study shows the importance of understanding and optimizing the heat treatment temperature for the production of biocarbon used as a filler in biocomposites based on the specific properties, application, yield, and hence cost effectiveness of the filler.