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United States Department of Agriculture

Agricultural Research Service


Location: Quality and Safety Assessment Research Unit

2008 Annual Report

1a.Objectives (from AD-416)
Enhancing value of fiber commodities, such as industrial fibers kenaf, flax, and cotton, through microbial and enzymatic activities. Design, develop, and test specific woven and non-woven materials for composites with specific properties and industrial applications. Specifically,.
1)optimize retting methods for separating high and consistent quality fibers from both seed- and fiber-type flax cultivars,.
2)develop standard methods and practices through established subcommittee D 13.17 of ASTM to objectively measure fiber properties,.
3)through ARS-USDA, governmental, and industrial collaborations, design and produce woven and non-woven flax fiber products for construction of composites for specific industrial applications.

1b.Approach (from AD-416)
Develop composites from flax fiber. Agricultural crops and products will be treated with microorganisms and enzymes that selectively remove fiber components and enhance value of products and processing methods. Treatments will be selected from available commercial enzymes and from newly isolated microorganisms and newly developed enzyme mixtures. Work will focus on improving retting procedures for obtaining fibers from bast plants such as kenaf and flax using enzyme mixtures containing pectinases, hemicellulases, and other non-cellulase enzymes that facilitate fiber separation from stems. Successful efforts at retting will be followed with research to scale up the process and work towards developing a commercial process for enzyme retting of bast fibers. Physical, chemical, and structural properties of treated fibers will be characterized by modern methods, and a body of knowledge will be developed to establish standards for evaluating fiber and fiber processing. New methods will be developed for rapid determination and evaluation of these standards.

3.Progress Report
Progress relates to National Program 306 Quality and Utilization of Agricultural Products, Component 2 New Processes, New Uses, and Value-Added Foods and Biobased Products, Problem Area 2c New and Improved Processes and Feedstocks. The early completion of the project milestones provided the opportunity to pursue the development of composite materials (see 1b Approach). Composites were prepared with flax fiber, flax shive, and flax fiber processing waste collected from commercial facilities. Composites were made by combining these solid fiber fractions with a biobased polymer matrix. Strength properties of these novel materials were determined using mechanical test equipment, e.g., Instron Tensile Tester. Spectroscopic techniques such as midrange FTIR-Attenuated Total Reflectance were also used for structural characterization. The effects of fiber composition and process conditions on composite flexibility and strength were quantified. These results showed that significant improvement in physical properties were obtained with low levels (1wt%) of added fiber materials. The design of composite materials for particular applications, e.g., controlled release, was achieved by modifying the polymer formulation. The recovery of additional co-products from flax fiber and processing waste materials was pursued using ethanol for the extraction of surface lipids and base or enzyme treatments to release phenolic acids (ferulic and coumaric) from lignified tissues. It was shown that membrane separation techniques could be used to separate these bioactive acids from an aqueous co-product stream by adjustments in pH. The chemistry of these isolated natural products were investigated by preparing glycerol esters of ferulic acid and cinnamic acid. This research shows promise as a technique to impart antioxidant and antibacterial properties to solid substrates such as textiles, nonwovens, and composites.

1. Composite materials made with flax fibers and flax fiber processing waste. Flax fiber fractions were combined with a glycerol adipate polymer matrix to prepare biocomposite materials. These biocomposites were analyzed and compared to similar materials prepared with cotton fiber. The flax containing products were stronger and more flexible than those made with cotton fibers. This accomplishment addresses National Program 306 Quality and Utilization of Agricultural Products, Component 2 New Processes, New Uses, and Value-Added Foods and Biobased Products, Problem Area 2a New Product Technology and 2b New Uses for Agricultural By-Products.

2. Extraction of lipid co-products from fiber processing waste. Ethanol was shown to be an effective solvent for the recovery of lipids from lignocellulosic substrates at moderately elevated temperature (50°C). Cooling of the extract permitted separation of the extracted components by size and polarity. This method was applied to flax fiber process waste streams but is generally applicable to biomass and shows promise for use in biomass to ethanol conversion facilities. This accomplishment addresses National Program 306 Quality and Utilization of Agricultural Products, Component 2 New Processes, New Uses, and Value-Added Foods and Biobased Products, Problem Area 2b New Uses for Agricultural By-Products.

5.Significant Activities that Support Special Target Populations

6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings2

Review Publications
Holser, R.A., Willett, J.L., Vaughn, S.F. 2008. Thermal and physical characterization of glycerol polyesters. Journal of Biobased Materials and Bioenergy. 2(1):1-3.

Holser, R.A., Akin, D.E. 2008. Extraction of Lipids from Flax Processing Waste Using Hot Ethanol. Industrial Crops and Products.

Last Modified: 4/17/2014
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