Location: Bioproducts Research2011 Annual Report
1a. Objectives (from AD-416)
Objective 1: Develop novel commercially viable composite materials from agricultural residues and industrial crops. a. Develop novel commercially viable fiber-reinforced composite materials. b. Develop novel commercially viable composite materials for agricultural applications and consumer goods. Objective 2: Develop novel technology to enable the commercial production of nanofibers from biopolymers. Objective 3: Develop commercially viable biobased polymers and polymer blends with improved functionality. Objective 4: Develop technologies to enable the commercial production of non-fuel commodity bioproducts from agricultural and biorefinery feedstocks and byproducts.
1b. Approach (from AD-416)
Novel commercially viable composite materials will be developed from agricultural fibers and binders. Fiber composites with superior strength and flexibility will be made by uniformly distributing agricultural fibers in matrices using and array of dispersants. Matrix materials will include biopolymers and inorganic binders. Fiber reinforced composites will also be made using micro and nanofibers made from biopolymers. Composite materials with liquid activated clumping properties will be made using agricultural binders with high molecular weight and strong hydrophilic properties. Composite materials that function as control-release devices will be developed both for controlling important agricultural pests and for providing plant nutrition and protection. The devices will utilize biodegradable, natural polymers and beneficial soil microbes. In addition to composite materials, micro and nanofibers and/or nanoparticles will be made from biopolymers using a solution blow spinning technology recently developed. Biopolymer solutions will be used to make an array of micro and nanofibers with active agents that provide functionality for applications for medical products and personal hygiene items. Nanoparticles from starch and/or cellulose will be produced by chemical and mechanical means. The materials will be used to make nanocomposites with improved strength and modulus. Low molecular weight polyesters will be made based on di and triols/diacids that can plasticize polylactic acid (PLA) or polyhydroxyalkanoates (PHA). PLA and PHA polymers containing the plasticizers will be tested for strength and stability by recording mechanical properties. Green pathways for making styrene and terephthalic acid will be explored along with other WRRC cooperators. The Bioproducts Group’s main focus in this collaborative effort will be to assist in characterizing the mechanical and physical properties of the biopolymers and partnering with industry to facilitate scale-up. Non-fuel commodity bioproducts from crop residues, fish waste and wheat gluten will be made. Cellulose fiber will be extracted from crop residues and processed into bioproducts including agricultural mulches and tessellated fiber board. Bioproducts from fish waste will include gelatin polymers for biomedical applications such as tissue scaffolding. Nanofibers from fish gelatin or blends of fish gelatin and other polymers will be made by electrospinning. Processing parameters will be optimized and fiber properties will be characterized using microscopy and analytical methods. Antibiotics will be incorporated into the fibers and films. The antimicrobial effectiveness of fibers will be compared to films as to their effectiveness against different bacteria using an overlay inhibition technique. Work on wheat gluten bioproducts will also be performed with the goal of developing natural protein polymers from vital wheat gluten that can be chemically modified to impart greater ability to absorb water. Formerly 5325-41000-044-00D (6/09). Replacing 5325-41000-051-00D (8/10)
3. Progress Report
Subsections listed below indicate the research progress achieved during the fiscal year 2011. Work has progressed in the development of bioproducts that include control-release devices for controlling mites in honeybee colonies and wax moths, improved pet litter, and fish waste products. Regarding control-release devices, the new gelling agent developed in 2010 was used to solidify a liquid active agent for reservoir-type control-release devices. The control-release devices were sent to ARS cooperators in Tucson, Arizona for evaluation in honey bee colonies. Work on developing biobased products for the pet litter industry was continued under an agreement with Clorox. A bentonite clay is currently used in commercial pet litter. A low-cost method of creating porous, lightweight litter was developed using surfactants. The density of the product was reduced by 50% which has the potential of significantly reducing shipping costs. However, the product performance is inferior to the current product. Further development is needed to merit commercialization. A fire retardant gel containing starch was developed as a means of helping prevent fire damage from wildfires such as those experienced in California. The starch additive helps reduce the drying rate of the gel and forms a film when exposed to intense heat that helps shield the substrate from heat. A patent for this product was approved by the patent committee and a manuscript has been submitted. Six genetic variants of wheat have been obtained from a WRRC collaborator. These new wheat types are of interest because the proteins in them have an increased number of potential crosslinks, a higher average molecular weight, and the compositions are more focused to a few proteins. To recover the protein we have investigated two separation methods: (1) a conventional, normally preferred, method of protein enrichment by dough development and starch washout that capitalizes on wheat protein properties at the seed stage; and (2) an alternative that fully solubilizes the protein by unfolding and may alternatively reduce the protein to shorter molecular weight (MW). The former method unexpectedly has been unable to recover any protein and preliminarily suggests a lower ability to adsorb water; whereas, the alternative is quantitative but makes use of concentrated detergent. Consequently, we have spent considerable effort to characterize the protein at the seed stage to verify some of the reported attributes and to characterize compositional and structural anomalies. This work has led to a collaboration between ARS scientists at the WRRC and WSU/ARS Grain Quality Lab, because some of the approaches taken locally could also have very important impact on wheat-for-bread characterization.
1. Fire-retardant gel containing starch. Fire-retardant gels, which are often applied to protect threatened structures lying in the path of large, intense fires, must be environmentally-friendly and cost effective. ARS scientists in Albany, CA, developed a fire gel from bentonite clay, water, and starch that is much more effective than water alone and is cheaper than commercially available gels. A quarter inch thick gel application provided nearly 30 minutes of protection from intense heat of over 900°F. Once application methods are optimized, these starch-based, “green” gels could be used to protect homes, out- buildings, equipment, and other property from potential fire damage.
Azevedo, H.M., Mattoso, L.H., Avena-Bustillos, R.J., Filho, G.C., Munford, M.L., Wood, D.F., Mchugh, T.H. 2010. Nanocellulose reinforced chitosan composite films as affected by nanofiller loading and plasticizer content. Journal of Food Science. 75(1):N1-N7.