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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Plant Polymer Research » Research » Publications at this Location » Publication #203357
Title: POLY(LACTIC ACID) GREEN COMPOSITES USING OILSEED COPRODUCTS AS FILLERS

Author
item Finkenstadt, Victoria
item Liu, Cheng Kung
item Evangelista, Roque
item Liu, Lin
item Cermak, Steven
item Hojillaevangelist, Milagros
item Willett, Julious

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2007
Publication Date: 7/1/2007
Citation: Finkenstadt, V.L., Liu, C., Evangelista, R.L., Liu, L.S., Cermak, S.C., Hojillaevangelist, M.P., Willett, J.L. 2007. Poly(lactic acid) green composites using oilseed coproducts as fillers. Industrial Crops and Products. 26(1):36-43.

Interpretive Summary: This work characterized a novel green composite from alternate oilseed coproducts and poly(lactic acid) fabricated by twin-screw extrusion and injection molding. The composites showed similar mechanical properties to some conventional polymer composites, and are biodegradable and competitive in cost with comparable non-sustainable petroleum based products currently in the marketplace. The manuscript also discusses several technical issues such as the effect of the filler/matrix ratio on the structural and mechanical properties of resultant composites and provides useful information for the studies of other natural fiber-reinforced biobased polymer composites. The current study presents a new way to utilize agricultural by-products for the future profitability of the agriculture industry.

Technical Abstract: Poly(lactic acid), PLA, is a biodegradable polymer made from renewable resources with similar mechanical properties to polypropylene. PLA is more expensive than petroleum-based plastics, and the use of low-cost fillers as extenders is desirable. Agricultural co-products of the alternative oilseed crops, cuphea(C), lesquerella(L) and milkweed(M), were collected after the oil was recovered. PLA and various levels of coproduct (0-45% w/w) were compounded by twin-screw extrusion and injection molded. As coproduct content increased, tensile strength for all PLA composites decreased consistent with the Nicolais-Narkis model. PLA-C exhibited increased stiffness. In contrast, the modulus of PLA-M & PLA-L decreased slightly. Unexpectedly, PLA-M showed extensive stress-cracking under tensile stress and exhibited an elongation value 50% to 200% greater than the PLA control. Acoustic emission showed ductile behavior of the PLA-M composite.