Submitted to: Journal of Agriculture and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2005
Publication Date: 11/4/2005
Citation: Liu, L.S., Fishman, M.L., Hicks, K.B., Liu, C. 2005. Biodegradable composites from sugar beet pulp and poly (lactic acid). Journal of Agriculture and Food Chemistry. 53(23)p. 9017-9022. Interpretive Summary: About 400 million tons of wet pulp is generated from U.S. beet sugar production that is subsequently either sold as low value animal feed or must be disposed in an environmentally acceptable manner, resulting in additional expense. Finding new ways to profitably utilize the enormous amounts of this biorenewable processing by-product is critical for the future profitability of the industry. In this study, sugar beet pulp was used to reinforce poly(lactic acid) to form thermoplastic composite materials using a process called compression-heating. The composites formed showed suitable mechanical properties for the use as lightweight construction materials. Such biodegradable materials are competitive in cost with comparable environmentally non-sustainable petroleum based products currently in the marketplace. Sugar beet growers and processors will benefit from this research by the creation of valuable new products from sugar beet pulp.
Technical Abstract: Sugar beet pulp and poly(lactic acid) composites were prepared by compression-heating. The resultant thermoplastics had a lower density, but they had similar or better tensile strength than pure poly(lactic acid) specimens as well as the same geometric properties. Tensile properties also depended on the initial water content of sugar beet pulp and the process by which composites were manufactured. In comparison with sugar beet pulp, the composite showed improved water resistance. This can be attributed to the hydrophobic character of poly(lactic acid) and pulp-matrix interactions. The composite thermoplastics showed suitable properties for potential use as lightweight construction materials.