Location: Plant Polymer Research2011 Annual Report
1a. Objectives (from AD-416)
Objective 1: Develop commercially viable polymer composites that contain soy- and cereal derived nanoparticle aggregates. Objective 2: Develop commercially viable polymer composites that contain carbonized agricultural byproducts and feedstocks as filler substitutes for carbon black. Objective 3: Develop new commercially viable biobased nanoparticles by copolymerization of biopolymer and biodegradable synthetic polymers.
1b. Approach (from AD-416)
This plan seeks to develop methods of producing nanoparticle aggregates from soybean, cereal grains, and biochar for polymer composite applications. The research includes developing economically viable methods using mechanical shear and chemically-induced rearrangements of proteins and carbohydrates to form nanoparticle aggregates and modifying their surface with both chemical and physical methods. The proposed experimental approaches will establish scientific working principles of bio-based nanocomposites by investigating size and shape of nanoparticle aggregates and their surface properties that can influence the properties of polymer composites. The proposed experiments will also investigate the mixing and flow behaviors of nanoparticles in polymer composites, and develop commercially viable processing technologies for these composites. The result will then be transferred to composite developers of various applications.
3. Progress Report
The goal of this project is to supplement petroleum-based fillers (carbon black) with bio-based fillers from renewable resources to contribute to our material sustainability. In the current development, production of soy based nanoparticles, corn stover biochar with high surface area, and coated protein nanoparticles were developed and evaluated for their potential in polymer composite and coating applications. An efficient high-shear process has been developed for the production of nanoparticles from soy based products. Various parameters such as concentration and alkalinity were developed to optimize the particle size, stability, and processing efficiency. Particle size, structure, and rheological properties of these nanoparticles were also characterized. An effective ball-milling process has been developed for corn stover biochar, which was ball-milled under a variety of controlled conditions such as the amount and type of solvent used, type of grinding media, and weight ratio of grinding media to biochar in order to determine the optimum conditions for reducing the particle size and, therefore, increasing the surface area. Nanoparticles were produced by chemically bonding a degradable synthetic polymer to several protein molecules. These nanoparticles strongly adhered onto the surface of hydrophobic materials. Wheat proteins were found to be the best choice for forming these nanoparticles. The strong adsorbing tendency of the produced nanoparticles was demonstrated, and detailed structure of nanoparticles was thermodynamically characterized. When these particles were used as a coating material for transparent materials such as glass panes and plexiglass, it changed their wetting properties without noticeably changing the transparency. To improve the dispersion stability of these nanoparticles, dextrans have been used as a stabilizer for these nanoparticles. To reduce the cost, starches treated with high pressure/temperature were found to be a suitable substitute for dextrans. The current progress contributes to the development of economical and renewable reinforcement fillers for polymer composite applications and has potential scientific and industrial uses for developers of polymer composites, coatings, and controlled-release of medicine.
1. Production of soy based nanoparticles. Nanoparticles are very tiny particles that have a very high surface area per weight; this causes them to be more reactive with certain other materials and have been used in applications such as plastics/rubber, coating, medicine, etc. Natural nanoparticles are renewable and environmentally friendly. A process using very large shredding forces was developed by ARS Plant Polymer Research Unit scientists at the National Center for Agricultural Utilization Research in Peoria, IL, to produce soy based nanoparticles efficiently. This development will have potential uses in the reinforcement of rubber/plastic materials and as adsorbing/releasing carrier for chemicals.
2. Production of improved biochar filler. Rubber composites made with renewable filler such as charcoal made from agricultural waste can supplement those made with carbon black in order to reduce the carbon footprint and decrease our nation’s dependence on fossil fuels. In order for this material to be an effective filler in rubber composites, the surface area must be maximized by reducing the particle size. The increased surface area will interact more strongly with the rubber matrix to make stronger composites. An efficient grinding process was developed by ARS Plant Polymer Research Unit scientists at the National Center for Agricultural Utilization Research in Peoria, IL, to produce filler material with a surface area significantly greater than that of carbon black. The improved charcoal has potential uses in reinforcing rubber materials, as black pigment, and as adsorption media for toxin filtration.
3. Preparation of protein nanoparticles. Nanoparticles made of chemically bonding a degradable synthetic polymer to proteins were developed by ARS Plant Polymer Research Unit scientists at the National Center for Agricultural Utilization Research in Peoria, IL. These nanoparticles can be used as a filler for rubber composites or as an agent to change surface wetting properties. As a surface modifying agent, these nanoparticles dramatically changed the wetting property of transparent materials without noticeably changing the transparency. This accomplishment will impact the technology of manufacturing windshield fluids by providing improved visibility for the automobile drivers in rainy conditions.
Jong, L. 2011. Aggregate structure and effect of phthalic anhydride modified soy protein on the mechanical properties of styrene-butadiene copolymer. Journal of Applied Polymer Science. 119(4):1992-2001.