2012 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.
The goal of this project is to develop renewable agricultural based particles for a variety of non-food applications. The current application focus is for industrial applications including polymer composites and coating applications, contributing to the improvement of environment and sustainability. In the current development, production of soy based nanoparticles, various biochars with high surface area, and coated protein nanoparticles were developed and evaluated for new potential applications.
An efficient process was developed to produce soy-based nanoparticles and incorporate them into natural rubber. Different filler compositions were evaluated to characterize the mechanical properties of rubber composites. The results showed that excellent reinforcement was established for the rubber composite with 10% soy filler. Competitive tensile properties were developed with 20% replacement of carbon black with soy nanoparticles in natural rubber composites.
Rubber composites reinforced with carbon black, biochar, and various blends of these two fillers were compared to determine what conditions yielded the best reinforcement properties. At low filler concentration (10% by weight), composites using 25-50% biochar blended with carbon black had superior material properties than those made with 100% carbon black. Automotive seals and gaskets are composites with low filler concentrations that could be produced using this technology, and thus carbon black usage could be reduced by up to 50%.
Additional research was performed on protein-cyanoacrylate nanoparticles. Optimum conditions for the production of these nanoparticles are dependent on the type of proteins employed. During this year, critical information on the reaction conditions such as most adequate solvent, relative amount of starting material, reaction time was obtained for the two types of proteins, a cereal protein and an animal protein. Experimental results revealed optimum conditions for the highest production efficiency.
The current progress contributes to the development of economical and renewable reinforcement fillers for polymer composite applications and renewable particles for coating applications. The developments also have potential scientific and industrial uses for other applications such as coloring pigments and controlled-release of flavor/medicine.
Use of renewable biochar to replace carbon black. Developing techniques using renewable feedstocks would reduce the carbon footprint of rubber products. ARS scientists in the Plant Polymer Research Unit at the National Center for Agricultural Utilization Research in Peoria, IL, tested biochar, produced from heating materials such as corn stover at high temperatures and low oxygen, in combination with carbon black in rubber formulations. Replacing up to 50% of the carbon black with the renewable biochar had distinct product advantages (higher strength, elongation and toughness) over the carbon black control. Flexible rubber parts manufacturers that produce automotive seals and gaskets could use biochar co-filled composites to reduce carbon black usage by 1-2 million pounds per year.
Production of novel nanoparticles for glass window clearners. While nanopartilces in solution may have very attractive properties, their inability to stay as discrete particles in solution limits their utility. These unstable nanoparticles come together over time, which precipitate out of liquids and become unusable. ARS, Plant Polymer Research Unit scientists at the National Center for Agricultural Utilization Research in Peoria, IL, developed optimum conditions for the production of stable nanoparticle solutions for two selected types of nanoparticles. An invention disclosure for these nanoparticles was submitted. This accomplishment will impact the technology of manufacturing glass-window cleaners and is expected to show superiority over the current commercial cleaners.
The use of soybean proteins to improve the strength of rubber. Currently carbon black, produced from petroleum is used to improve the strength of rubber products. There is a need for renewable alternatives to carbon black. Renewable natural particles are especially useful in terms of their high surface area for rubber reinforcement. ARS scientists in the Plant Polymer Research Unit at the National Center for Agricultural Utilization Research in Peoria, IL, have produced soy based nanoparticles efficiently and used them to increase the mechanical strength of natural rubber. It was found that replacing 20% of the carbon black with soy based nanoparticles produced rubber products with good mechanical properties. This development will increase the renewable content in rubber products. It will also increase the value of soybean crops and benefit U.S. farmers.
Jong, L. 2012. Mechanical properties of heterophase polymer blends of cryogenically fractured soy flour composite filler and poly(styrene-butadiene). Journal of Elastomers and Plastics. 44(1):273-295.
Jong, L. 2012. Mechanical properties of melt-processed polymer blend of amorphous corn flour composite filler and styrene-butadiene rubber. International Journal of Polymeric Materials. 61(6):448-465.
Peterson, S.C. 2012. Evaluating corn starch and corn stover biochar as renewable filler in carboxylated styrene-butadiene rubber composites. Journal of Elastomers and Plastics. 44(1):43-54.
Peterson, S.C., Jackson, M.A., Kim, S., Palmquist, D.E. 2012. Increasing biochar surface area: optimization of ball milling parameters. Journal of Powder Technology. 228(1):115-120.
Eller, F.J., Peterson, S.C., Sessa, D.J. 2012. Pressurized solvent extraction of pure food grade starch. Carbohydrate Polymers. 87(4):2477-2481.
Kim, S., Peterson, S.C. 2012. Development of degradable polymer composites from starch and poly(alkyl cyanoacrylate). Polymer Composites. 33(6):904-911.