Location: Plant Polymer Research
2019 Annual Report
Objectives
The overall goal is to produce novel bio-based materials from agricultural commodities to increase the market demand and value of U.S. non-food agricultural products and by-products, as well as to reduce the environmental impact from the plastics industry.
Objective 1. Enable, from a technological standpoint, the commercial production of new bio-based polymers, graft-copolymers, composites, and blends from polysaccharides.
Sub-Objective 1A. Selectively modify polysaccharides to provide higher product value using state-of-the-art, chemical methods and physical techniques, such as microwave, ultrasound, supercritical fluids, and on-line monitoring to produce materials suitable for coatings, personal care, food, and pharmaceutical applications.
Sub-Objective 1B. Synthesize and evaluate bio-based polymers, polymer blends and polymer composites for environmentally responsive plastics, controlled release materials, and composite materials using industrial, continuous production methods such as extrusion.
Approach
Environmental concerns over the production and disposal of polymeric materials have prioritized the creation of new bio-based materials from agricultural feedstocks. Sustainable processing technologies are also needed to replace industrial and consumer products made from petroleum based feedstock. This project focuses on making bio-based polymeric materials with useful applications from agricultural products such as starch and associated low cost corn processing and harvesting co-products. Modified biopolymers with new properties will be prepared using the latest technologies available. Specific objectives for this project include: 1) Develop novel carbohydrate-based materials, such as starches, celluloses, and chitosan, with novel structures and/or through the use of microwaves, autoclave heating, reactive extrusion, jet cooking, and other green chemical methods; and 2) Demonstrate that the biobased polymeric materials can be used in high-value applications such as composite materials, packaging, controlled release devices, and environmental responsiveness. As an example, starch-based copolymers with novel and unique properties will be compounded by reactive extrusion, characterized, and processed into films or fibers and then evaluated for targeted properties and specific applications.
Overall, this research will lead to bio-based polymer products with new or improved properties, have lower cost, are more environmentally friendly, and thus more acceptable to consumer markets. It will also generate new bio-based technologies enabling new market opportunities for agricultural products while reducing the environmental footprint relative to polymeric materials based on non-renewable resources.
Progress Report
Food packaging based on nanotechnology. Many foods are very sensitive to oxygen, which is responsible for the deterioration of many products either directly or indirectly. By utilizing palladium and cellulose nanoparticles, we produced a novel active packaging material that could scavenge oxygen effectively and thus preserve foods by eliminating oxygen. These nanocomposite films seem to have promising active packaging properties, where the packaging material exhibits desirable functions in addition to containment of product. One of these functions is to reduce the oxygen content in the package in order to minimize product oxidation and spoilage and prolong product shelf-life. We have developed novel nanocomposites, comprising poly(ethylene-co-vinyl alcohol) (EVOH), palladium nanoparticles, and cellulose nanocrystals. The nanocellulose reduces palladium precursor to palladium metal and enhances the physical properties of the EVOH film. Palladium nanoparticles react with oxygen to serve as the oxygen scavenger. The cellulose nanocrystals have also been optionally oxidized, which exhibits improved oxygen absorption. These features make the nanocomposites promising candidates as active packaging materials which could be potentially used by food packaging industries.
A new solvent system containing water and Natural Deep Eutectic Solvents (NADES) was used for the extraction of sugars from crops. Over-ripe bananas serve as a good source for non-starch polysaccharides (NSP), which can be used as a functional food ingredient and represent an opportunity for waste utilization. However, ripe banana contains a large amount of sugars which are undesirable and need to be removed. Traditional extraction methods using alcoholic solvents have many drawbacks. This study aims to use natural deep eutectic solvents (NADES) as new and eco-friendly solvents for the extraction of soluble sugars from ripe bananas. Thirty NADES were characterized and screened, and four of them were selected as the most appropriate solvents to remove soluble sugars from banana puree with the help of microwave-assisted extraction. The effects of temperature, time, and quantity of water added to NADES were evaluated. In all cases, NADES were shown to be more effective than conventional solvents (water and ethanol). Among the four NADES, malic acid:beta-alanine:water (1:1:3, molar ratio) with 30 g/100 g of water (25°C, 30 min) was found to be the most effective in the extraction of soluble sugars from banana puree. Thus, NADES can be considered a highly efficient extraction medium for fruits (such as bananas) and can replace conventional extractions using harsher organic solvents like ethanol.
Accomplishments
1. Cashew gum/gelatin blend as encapsulating agent. ARS scientists in Peoria, Illinois, have successfully developed cashew gum/gelatin complex. The objective of our work was to produce and characterize pequi oil microparticles using cashew gum/gelatin matrix (CG/GE) through complex coacervation. Pequi oil has medicinal and cosmetic uses. Cashew gum has excellent potential as an encapsulation matrix, representing an alternative to expensive Gum Arabic. Since cashew gum is a by-product of the cashew industry and has little commercial value, the possibility of using cashew gum for encapsulation should be a welcome development for the industry. The science and processes developed during this research will be useful for making other bio-oil complexes and new applications and thus help the oilseed farmer.
2. Synthesis of fatty acid-based ionomers. One of the desirable research goals today is to convert agro-based raw materials into low-cost functional polymers. Among the readily available natural raw materials are the fatty acids that can be obtained from hydrolysis of plant oils or from the paper industry as byproducts. ARS scientists in Peoria, Illinois, have shown that the tall oil fatty acids/iron/C02/water reaction system produced a new type of polymer. Through a combination of different analytical techniques, we have managed to decipher the major reaction pathways of this novel synthetic process. An advantage of this new ionomer is its low molecular weight that enables it to be readily soluble in a solvent and can be made into different physical forms, such as solid block, film, or foam. The novel reaction disclosed in this work will promote the utilization and creation of a new market for bio-oil and tall oil fatty acids.
3. Microwave-assisted synthesis of sorbitol polyurethanes and their network with polycaprolactone and soybean oil. Because of the current interest in sustainability, environmental stewardship, and green chemistry, there has been a lot of interest in using agro-based raw materials for the design of polymeric materials. One of the promising bio-renewable materials is sorbitol, which can be produced from corn syrup, is inexpensive, and widely available. ARS scientists in Peoria, Illinois, have focused on sorbitol and shown that polyurethanes can be readily made from it through conventional or microwave heating. The microwave-assisted synthesis was found to significantly decrease the reaction time and save energy relative to conventional heating. The novel processes disclosed in this work will benefit industrial chemical manufacturers, such as National Starch and Ingredion among others, to save time and energy during the production of sorbitol-based polyurethane. Developing value-added products from agricultural commodities helps the farmer and the U.S. economy.
Review Publications
Gómez, A.V., Biswas, A., Tadini, C.C., Furtado, R.F., Alves, C.R., Cheng, H.N. 2019. Use of natural deep eutectic solvents for polymerization and polymer reactions. Journal of Brazilian Chemical Society. 30(4):717-726.
Gómez, A.V., Tadini, C.C., Biswas, A., Buttrum, M., Kim, S., Boddu, V.M., Cheng, H.N. 2019. Microwave-assisted extraction of soluble sugars from banana puree with natural deep eutectic solvents (NADES). LWT - Food Science and Technology. 107:79-88. https://doi.org/10.1016/j.lwt.2019.02.052.
Biswas, A., Kim, S., Buttrum, M.A., Furtado, R.F., Alves, C.R., Cheng, H.N. 2018. Preparation of hydrophobically modified Cashew Gum through reaction with Alkyl Ketene Dimer. Green Polymer Chemistry: New Products, Processes, and Applications. ACS Symposium Series. 1310:137-146.
Stone, D.A., Biswas, A., Liu, Z., Boddu, V., Cheng, H.N. 2019. Synthesis and characterization of an iron-containing fatty acid-based ionomer. International Journal of Polymer Science. Vol. 2019, Article ID 3024784, 9 pp. https://doi.org/10.1155/2019/3024784.
Gómez, A.V., Biswas, A., Tadini, C.C., Vermillion, K., Buttrum, M., Cheng, H.N. 2018. Effects of microwave and water incorporation on natural deep eutectic solvents (NADES) and their extraction properties. Advances in Food Science and Engineering. 2(4):125-135. https://dx.doi.org/10.22606/afse.2018.24004.
Biswas, A., Kim, S., Furtado, R.F., Alves, C.R., Buttrum, M., Boddu, V.M., Cheng, H.N. 2018. Metal chloride-catalyzed acetylation of starch: Synthesis and characterization. International Journal of Polymer Analysis and Characterization. 23(6):577-589.
Biswas, A., Cheng, H.N., Kim, S., Appell, M.D., Boddu, V.M., Alves, C.R., Furtado, R.F. 2019. Preparation of sorbitol-based polyurethanes and their semiinterpenetrating polymer networks. Journal of Applied Polymer Science. 136:47602. https://doi.org/10.1002/app.47602.
Cherpinski, A., Biswas, A., Lagaron, J.M., Dufresne, A., Kim, S., Buttrum, M.A., Espinosa, E., Cheng, H.N. 2019. Preparation and evaluation of oxygen scavenging nanocomposite films incorporating cellulose nanocrystals and Pd nanoparticles in poly(ethylene-co-vinyl alcohol). Cellulose. 26(12):7237-7251. https://doi.org/10.1007/s10570-019-02613-8.
