Location: Plant Polymer Research2011 Annual Report
1a. Objectives (from AD-416)
The long-term objectives of this project are to develop new technologies and knowledge to enable expanded growth of biobased materials, new market opportunities for agricultural products, and reduced environmental impact. Objective 1: Develop and characterize electroactive materials from natural polymers that enable commercially viable technologies. Objective 2: Develop and characterize stimulus-responsive starch-based materials that enable the commercially viable technologies. Objective 3: Develop cutting-edge computational tools for starch and other natural polymers using density functional theory and empirical energy approaches that enable development of new technologies.
1b. Approach (from AD-416)
Develop new biobased materials with novel properties from starch-based commodities. Novel properties include electroactive and stimuli-responsive polymeric materials. Develop molecular modeling tools for use in rational design approaches.
3. Progress Report
ARS Plant Polymer Research Unit scientists at the National Center for Agricultural Utilization Research in Peoria, IL, determined structure-function properties of agricultural polymers. Specifically, we studied bacterial exopolysaccharides and starch polymers as a corrosion inhibitor but the far-ranging applications could be biosensors, environmentally sensitive membranes, artificial muscles, actuators, electronic shielding, visual displays, solar materials, and components in high-energy batteries. Studies were initiated with a university partner to characterize large molecules using light scattering; this information will allow correlation of structural components to functional properties. In addition, starch was combined with soybean oil to form a water-resistant composite and evaluated for anti-corrosion ability using electrochemical methods. The starch-oil films were examined by microscope and characterized for coating integrity, roughness, and oil encapsulation. Starch-oil composites are used as lubricants. Molecular modeling tools were utilized to suggest methods of synthesis for cyclodextrins, to determine the structure of cellulose fragments, and to investigate the solubility of carbohydrates. There are no beta-linked cyclodextrins experimentally known today, however, alpha-linked cyclodextrins are a billion dollar business. Cellulose crystals all show, by experimental techniques, flat conformations, while the single chains calculated by Density Functional Theory (DFT) methods all show a twist. This information is important in the determination of the mechanism of how specific enzymes cleave cellulose. In particular, it is important in the production of ethanol from non-food source agriculture crops. Understanding the solubility of hydrophilic carbohydrates is critical for many physical properties and for their transformation into industrially important commodities. This work clearly showed that explicit water molecules in models are not required to understand the interaction of glucose with its solvent.
1. Anticorrosive dry lubricants. ARS Plant Polymer Research scientists at the National Center for Agricultural Utilization Research in Peoria, IL, demonstrated that thin starch-oil composite coatings provided protection to steel substrates in corrosive environments. They determined that there is a critical concentration of soybean oil above which no further protection is added thus establishing a cost-saving application. Corrosion of metals is a serious and challenging global problem faced by indusry. An established ARS technology, starch-oil composites are used as lubricants for metal parts and machinery.
2. Structures of important biobased polymers. ARS Plant Polymer Research scientists used sophisticated molecular modeling tools to 1) suggest new methods for synthesis of industrially-important novel cyclodextrin which has several uses as delivery devices for environmentally friendly agriculture chemicals and medically important biologics; 2) determine the structure of cellulose crystals which is important in the determination of the mechanism of how specific enzymes cleave cellulose for the production of biofuels; and 3) investigated the solubility of carbohydrates which will aid in the utilization of non-food agricultural commodities and transformation into value-added products.Finkenstadt, V.L., Cote, G.L., Willett, J.L. 2011. Corrosion protection of low-carbon steel using exopolysaccharide coatings from Leuconostoc mesenteroides. Biotechnology Letters. 33:1093-1100.