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
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. 51(1):26-35. 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 (HTS) is a renewable material that can be used to modify the surface chemistry of small particles. In this work, HTS was used to coat hydrophilic biochar particles in order to make them more hydrophobic. Then, when added as filler to hydrophobic styrene-butadiene rubber (SBR), 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) HTS showed increases of 59% in the ultimate tensile strength, 49% in elongation percentage, and 79% in fracture toughness of SBR composites compared to unmodified biochar particles. This shows that HTS can be used to improve the tensile properties of composites filled with biochar and potentially other hydrophilic filler materials.