Location: Plant Polymer Research
2023 Annual Report
Objectives
Objective 1. Enable new food-contact active packaging and coating materials through selective chemical modification and novel processing techniques.
The focus of Objective 1 is to design new food packaging materials from biobased and renewable-sourced polymers using novel physical processes and chemical modifications. The products will protect and enhance food products, eliminate or reduce pathogens, address antimicrobial resistance, extend shelf-life, and reduce food waste and food poisoning incidents.
Objective 2. Enable commercialization of new agro-based value-added green products and processes.
Objective 2 utilizes renewably sourced polymers, polymer blends, modified polysaccharides, and bio-oils to provide high-value products using state-of-the-art chemical and physical techniques, such as microwave processing, reaction chemistry and separations in ionic liquid and deep eutectic solvents, reactive extrusion, electrospinning, electrospraying, and nanotechnology. Through Objective 2, we envision the development of new or improved biopolymers made from agro-based raw materials targeted for plastic replacements (biodegradable polymers and plasticizers), adhesives (melt and pressure sensitive), personal care and cosmetics (dispersants, emulsifiers, bioactive agents), biobased phase change materials for thermal insulation, energy storage and conservation, and specialty materials (coatings, thickeners, adsorbents, metal ion sequestrants, flocculants, and catalyst supports).
Moreover, this project will yield modified industrial and commercial processing methods that will increase the efficiency and lower the cost for replacement of similar non-renewable polymer products. Polymeric materials from renewable resources will provide environmental benefits over materials currently in use. New fundamental knowledge of the interactions of plant-based carbohydrates with additives and polymers will provide the basis for a rational design of novel agro-based materials with targeted properties. See Appendix 1A for a flow diagram of the project.
Approach
The main outcome of this project is to develop environmentally friendly green processes and products by adopting circular bio-economy strategies. The first objective is to design new food packaging materials from biobased and renewable-sourced polymers using novel physical processes and chemical modifications. These packaging materials are intended to protect and enhance food products, promote food safety, eliminate or reduce pathogens, extend shelf-life, address antimicrobial resistance, reduce food waste and lead to greater availability of food to human, animal, and plant life. Active packaging materials will reduce the number of pathogens in food and food products through controlled release mechanisms. The second objective utilizes agro-based polymers, polymer blends, modified polysaccharides, and triglycerides (including sorghum and hemp oils) to develop high-value products using state-of-the-art chemical and physical techniques, such as microwave processing, ionic liquid and deep eutectic solvent reactions and separations, reactive extrusion, electrospinning, electrospraying, and nanotechnology. Overall, the project will develop agro-based polymer products that have new or improved properties at lower cost, have reduced environmental footprint, and are responsive to evolving consumer markets. The project will also generate innovative technologies, thereby enabling new market opportunities for agricultural products to replace polymeric materials based on non-renewable resources. This research will widen the application boundaries of agriculture, thereby increasing the demand, value, and utility of agricultural commodities.
Progress Report
A current societal problem is the accumulation of microplastics which is bad for the environment. Researchers find that these tiny pieces of plastic travel great distances, threatening the ocean ecosystem. A lot of research and development is ongoing to replace the plastics in coatings and packaging. In this connection, ARS researchers in Peoria, Illinois, have been exploring the blends of cellulosic derivatives and plant proteins as agro-based, biodegradable, and sustainable alternatives to plastics. One option is to use the blends of a food-grade cellulosic polymer and cottonseed protein, with a plasticizer. ARS researchers have produced these blends as single-layer films, consisting of different proportions of each component and plasticizer. They performed opacity, water permeation, mechanical properties and colorimetry analyses on these samples. These blends can possibly be used as water-soluble food packaging and coatings and as dissolvable bags and pouches for food items or for laundry detergents and cleaners. Utilization of cotton by-product cottonseed meal for this higher value application will mean more value for U.S. cotton farmers. This work also satisfies milestone 36 months, Objective 1. Refine formulas and processing for targeted applications (such as ready-to-eat foods and bagged produce).
In addition to being a major edible oil, soybean oil has attracted a lot of attention as a good biodegradable and sustainable raw material to produce specialty chemicals and polymers. ARS researchers in Peoria, Illinois, have recently discovered a green method to polymerize soybean oil by first converting it to an epoxide, which is polymerized via the use of citric acid. The physical properties of the resulting material can be enhanced through the incorporation of cellulose nanofibers. Detailed studies are ongoing to understand the chemistry of this material in greater detail to further improve the reaction efficiency. This work also satisfies milestone 36 months, Objective 2. Enable commercialization of new agro-based value-added, green products and processes.
Jojoba oil is a natural wax ester, comprising a monoester of long-chain fatty acids with cis olefins. Isomerization of cis olefin to trans olefin is often a desirable method to produce new products with different properties and reactivities. ARS researchers in Peoria, Illinois, have found a novel process involving the use of a catalyst, in supercritical carbon dioxide that quantitatively converts a compound possessing an isolated cis into a trans olefin. The utility of this reaction has been demonstrated by the conversion of cis olefins to its trans isomers in jojoba oil. Jojoba oil is liquid at room temperature with a melting point of about 10 degrees C; the reacted product is a solid with a melting point of 37 degrees C (around the normal human body temperature). This product may potentially be used for cosmetic, personal care, and medicinal applications. This work relates to Objective 1B, where we utilize agro-based polymers (including triglycerides) to develop high-value products, and jojoba is related to the triglycerides. This work also satisfies milestone 36 months, Objective 2. Enable commercialization of new agro-based value-added, green products and processes.
Accomplishments
1. Developed bilayer film of polylactic acid and cottonseed meal that may be a replacement for pollutant plastics. There is a concern that accumulation of pollutant microplastics in the environment may have negative consequences. Developing new biodegradable biobased films for food packaging to reduce plastic waste and microplastics is a possible solution. ARS researchers in Peoria, Illinois, have devised a new type of polylactic acid (PLA) film by incorporating cottonseed meal (CSM), an inexpensive protein-rich raw material from cotton manufacturing. Both PLA and CSM are agro-based, sustainable, and biodegradable. Direct mixing of PLA and CSM was difficult because they have no mutual solvents, and the two materials were not easily compatible. Therefore, PLA and CSM were combined as bilayer films. Mechanical properties, opacity, water vapor permeation, FT-IR, and thermal analyses of the films demonstrated that the bilayer films can be made and exhibit suitable film packaging properties. The new materials may be used as bioplastics in food packaging replacing polymers made from petroleum-based materials and providing added value to the cotton industry.
Review Publications
Biswas, A., Cheng, H.N., Kuzniar, G.M., He, Z., Kim, S., Furtado, R.F., Alves, C.R., Sharma, B.K. 2023. Bilayer films of Poly(lactic acid) and cottonseed protein for packaging applications. Polymers. 15(6). Article 1425. https://doi.org/10.3390/polym15061425.
Cheng, H.N., Furtado, R.F., Biswas, A., Alves, C., Prieto, C., Lagaron, J.M. 2023. Chemical modifications and applications of cashew byproducts - A selective review. ACS Food Science and Technology. 3:546-552. https://doi.org/10.1021/acsfoodscitech.2c00168.
