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Title: Modifications Caused by Enzyme-retting and Their Effect on Composite Performance

Author
item Foulk, Jonn
item RHO, DENNIS - National Research Council - United States
item ALCOCK, MERCEDES - Composites Innovation Center
item ULVEN, CHAD - North Dakota State University
item HUO, SHANSHAN - North Dakota State University

Submitted to: Advances in Materials Science and Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/14/2011
Publication Date: 9/16/2011
Citation: Foulk, J.A., Rho, D., Alcock, M., Ulven, C., Huo, S. 2011. Modifications Caused by Enzyme-retting and Their Effect on Composite Performance. Advances in Materials Science and Engineering. Volume 2011, Article ID 179023, 9 pages doi:10.1155/2011/179023

Interpretive Summary: Natural fibers produce desirable and quality products that are cultivated and derived from sustainable resources rather than petroleum. Fiber production creates numerous byproducts with diverse commercial uses. Flax (Linum usitatissimum L.) has been grown throughout the world for millennia. The utility of enzyme-retted flax fibers for creating a composite with thermosetting vinyl ester resin has been investigated and evaluated for physical and mechanical properties. The addition of flax fiber in thermosetting vinyl ester resin reinforces the material and reduces the amount of non-biodegradable materials. Physical properties of these enzyme-retted flax fibers varied among enzyme treatments. Composite tests indicate composite panels are largely unchanged among fiber samples. Variation in composite performance might not be realized due to poor interfacial bonding being of larger impact than the more subtle changes incurred by the enzyme treatment.

Technical Abstract: Bethune seed flax was collected from Canada with seed removed using a stripper header and straw pulled and left in field for several weeks. Unretted straw was decorticated providing a coarse fiber bundle feedstock for enzyme treatments. Enzyme treatments using a bacterial pectinolytic enzyme with lyase activity were conducted in lab-scale reactors. Four fiber specimens were created: no retting, minimal retting, moderate retting, and full retting. Fiber characterization tests: strength, elongation, diameter, metal content, wax content, and pH were conducted with significant differences between fibers. Thermosetting vinyl ester resin was used to produce composite panels via vacuum assisted infusion. Composite performance was evaluated using fiber bundle pull-out, tensile, impact, and interlaminar shear tests. Composite tests indicate composite panels are largely unchanged among fiber samples. Variation in composite performance might not be realized due to poor interfacial bonding being of larger impact than the more subtle changes incurred by the enzyme treatment.