Location: Plant Polymer ResearchTitle: Using heat-treated starch to modify the surface of biochar and improve the tensile properties of biochar-filled stryene-butadiene rubber composites Author
Submitted to: Journal of Elastomers and Plastics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2018
Publication Date: 4/12/2018
Citation: Peterson, S.C., Kim, S. 2018. Using heat-treated starch to modify the surface of biochar and improve the tensile properties of biochar-filled stryene-butadiene rubber composites. Journal of Elastomers and Plastics. doi: 10.1177/0095244318768636.
DOI: https://doi.org/10.1177/0095244318768636 Interpretive Summary: Filler materials are used to improve properties and/or reduce costs of rubber composites (such as tires). Biochar is a promising new filler material for the tire industry because unlike carbon black (the current industry standard), it is renewable. However, biochar is typically not as effective as carbon black as a filler because it usually has a higher content of impurities, and the surface chemistry is not similar. In this work, a renewable heat-treated starch is used to change the surface chemistry of biochar to make it more compatible with the rubber matrix. This significantly improves the biochar as a reinforcing filler and heat-treated starch may be applicable to other filler materials that have similar surface chemistry to biochar.
Technical Abstract: Heat-treated starch is a renewable material that can be used to modify the surface chemistry of small particles. In this work, heat-treated starch was used to coat hydrophilic biochar particles in order to make them more hydrophobic. Then when added as filler to hydrophobic styrene-butadiene rubber, the coated biochar dispersed more easily and had enhanced filler-matrix interactions, which were reflected in the tensile properties of the final composites. Biochar particles modified with 5% (weight) heat-treated starch showed increases of 59% in the ultimate tensile strength, 49% in elongation percentage, and 79% in toughness of styrene-butadiene rubber composites compared to unmodified biochar particles. This shows that heat-treated starch can be used to improve the tensile properties of composites filled with biochar and potentially other hydrophilic filler materials.