Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2006
Publication Date: 3/26/2006
Citation: Finkenstadt, V.L., Cermak, S.C., Willett, J.L. 2006. Preparation and characterization of poly(lactic acid) green composites using agricultural co-products as fillers [abstract]. American Chemical Society. n.10.
Technical Abstract: Poly(lactic acid) is a biodegradable plastic made from renewable resources and has similar mechanical properties to polypropylene. PLA is more expensive than petroleum-based plastics, and the use of low-cost fillers and extenders is desirable. Agricultural co-products (AcP) were collected after initial processing. Cuphea (C), Lesquerella (L), and Milkweek (M) are oil seed crops (pressed seed cake). Apple (A) pulp is waste from cider production. PLA was melted then AcP (0%, 8%, 15%, 22%, 30% and 45% w/w) was added producing a homogeneous resin which was injection molded. As AcP content increased, tensile strength for all PLA composites decreased as predicted by the Nicolais-Narmkis equation. PLA-C & PLA-A exhibited increased stiffness. In contrast, the modulus of PLA-M & PLA-L decreased slightly. Unexpectedly, PLA-M showed extensive stress-cracking and exhibited an elongation value 50% to 200% more than the PLA control. All other PLA-AcP composites exhibited lower elongation than PLA as expected.