Source: UNIVERSITY OF NEBRASKA submitted to
PROCESS AND PROPERTY INVESTIGATIONS OF FIBERS FROM NEBRASKA'S AGRICULTURAL PRODUCTS AND BY-PRODUCTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0192057
Grant No.
(N/A)
Project No.
NEB-37-035
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Apr 1, 2007
Project End Date
Mar 31, 2012
Grant Year
(N/A)
Project Director
Yang, YI.
Recipient Organization
UNIVERSITY OF NEBRASKA
(N/A)
LINCOLN,NE 68583
Performing Department
Textiles, Merchandising & Fashion Design
Non Technical Summary
A. The performance properties of PLA need to be improved before PLA can be broadly used as a major textile fiber. B. It is possible to use agricultural product to produce one of its two monomers, 1,3 PDO. But the problem is the high purification cost, which prohibits the production of PTT using renewable resources. C. The substantial increase in use of agricultural products for industrial applications, especially for biofuel production, results in increased quantity of byproducts with very limited use and low price. Without finding high value applications, the success of our biofuel industry and other bioindustries in Nebraska and in U.S. will be questionable. This project addresses these three challenges and attempt to provide answers to them for both the agricultural and textile industries. A. We want to improve the properties of PLA fibers, so that it could be used as a major textile fiber and thus benefit both agriculture and textile industries. B. We want to find uses of PDO from Nebraska's bioindustry and to add value to our agricultural products. C. We want to develop high value addition products from the byproducts, biomass and proteins, from Nebraska and the country.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5111599200030%
5111599202050%
5111820200010%
5111820202010%
Knowledge Area
511 - New and Improved Non-Food Products and Processes;

Subject Of Investigation
1599 - Grain crops, general/other; 1820 - Soybean;

Field Of Science
2020 - Engineering; 2000 - Chemistry;
Goals / Objectives
The main focus of this research outline is continue to improve the processing and performance properties of PLA (polylactide) and PTT (polytrimethylene terephthalate) fibers, and to develop new cellulosic and protein fibers using agricultural byproducts from Nebraska with compatible prices and good performance properties. Objective 1 of this outline is to improve the processing and performance properties of PLA fibers. More specifically, we plan (a) to develop dyeing technologies that will provide dye uptake and fastness properties same as or better than the currently recommended dyeing technologies but will substantially improve the retention of mechanical properties of PLA fiber; (b) to study the effect of lactic acid structures (D- and L-), polymer structures (D-, L- ratio, and possible structure modification), and fiber structure (different drawing, texturing and finishing conditions) on properties of the fiber; (c) to study the effect of PLA polyblended with another polymer, such as polypropylene on the properties of the fiber; and (d) to develop home care conditions for PLA textiles. Objective 2 of this outline is to develop a new method of making high quality PTT fibers with compatible prices using 1,3 PDO from Nebraska agricultural industry. More specifically, we plan (a) to evaluate the possibility of making PTT fiber from high IV PTT polymer mixed with low purity 1,3 PDO and different amount of terephthalate during high temperature extrusion; (b) to evaluate the possibility of spinning PTT fiber from polymers made from different ratios of high purity to low purity 1,3 PDO; (c) to develop a low cost 1,3 PDO purification method appropriate for the production of fiber quality polymers and fibers; and (d) to evaluate the processing and performance properties of the fibers made from a, b, and c. Objective 3 of this outline is to develop cellulosic and protein fibers using agricultural byproducts from Nebraska with compatible prices and good performance properties. More specifically, we plan (a) to develop cellulosic fibers from Nebraska agricultural byproducts, such as corn and sorghum stovers and wheat straw;(b) to develop protein fibers from Nebraska agricultural byproducts such as zein from corn distillers grain, soy protein from the byproduct of biodiesel production, wheat gluten and chicken/turkey feathers; (c) to explore applications of the new cellulosic fibers in textile and composite industries; and (d) to explore applications of the new protein fibers in textile, composite and medical industries.
Project Methods
This research will study the ratio and the arrangement of D-, and L-lactic acid units in the polymer. The structure of the polymer thus made will be obtained by both large and small-angle X-ray diffraction studies, mainly the crystal structures and orientations. The polymer orientations in both crystalline and amorphous regions will be determined by sonic modules measurement. The information from both X-ray and sonic modules will then help characterizing the structures of both crystalline and amorphous areas of the fiber. AATCC home care conditions will be followed for the home care study. The changes of the morphological structures, polymer structures and mechanical structures of the PLA textiles after laundering will be investigated. The hydrolysis of the material due to different home care treatment will be found. The relationship between PLA hydrolysis and home care conditions will be established and the most appropriate home care conditions for PLA materials will be found. The initial challenge in making PTT fiber from Nebraska 1,3 PDO is the purity of the PDO. We will mix 1,3 PDO from Nebraska with different amounts of terephthalate and a certain portion of PTT with high viscosity values, e.g. 1.3 dl/g. The mixing will be in the melts during extrusion, and/or in the reactor for further polymerization before extrusion. If the mixing during extrusion will allow enough polymerization to obtain the polymer with excellent spinning and performance properties, the polymerization before extrusion will not be studied, due to the additional processing cost. The extrusion will be at our own laboratory. Independent variables being studied are amount of Nebraska 1,3 PDO, amount of terephthalate, and amount and viscosity of high purity 1,3 PDO. The evaluation methods are viscosity determination of the polymer before and after extrusion and the mechanical and appearance properties of the extruded fibers. Corn and sorghum stovers and wheat straw will be used as raw materials to develop fibers. Chemical, enzymatic and a combination of chemical and enzymatic methods will be used to extract natural cellulosic fibers from these biomasses. The relationship between extraction conditions, fiber structures (mainly cellulose, lignin, hemicellulose and metal contents, and crystal and morphological structures), and performance properties of the fibers will be established. Proteins from distillers grains, soymeal after biodiesel production, wheat gluten and feathers will be extracted and the extraction conditions will be optimized. The proteins will then be dissolved using different solvents, redox reactions, plasticizers and swelling agents under different temperatures and pHs. Fibers will then be produced. Traditional solution spun fibers, including both dry and wet spun fibers and the new electrical spun fibers will be made. These fibers will be characterized for their fiber structures (mainly cellulose, lignin, hemicellulose and metal contents, and crystal and morphological structures), and performance properties. From the relationship between the fiber quality and fiber production conditions, the best conditions to make the fibers will be recommended.

Progress 04/01/07 to 03/31/12

Outputs
OUTPUTS: The results from this project were used to enrich the contents of Biotextiles and New Fibers sections of courses in the Departments of Textiles, Merchandising and Fashion Design (TMFD 405, 406, 805 and 806) and Department of Biological Systems Engineering (AGEN-BSEN 225 and 303). The research from this project was used to mentoring undergraduate students (3 UCareand 1 McNair) and graduate students (5 PhD and 7 MS students from both TMFD and BSE departments). The results from the project were presented 56 times in various national and international conferences, including American Chemical Society National meetings, the annual symposium of the Consortium for Plant Biotechnology Research, International Conference on Advanced Fibers and Polymer Materials, AICHE Annual Meeting, and Annual Corn Utilization and Technology Conference. I have invited to present 61 times to various local, state, national and international meetings for the work we have been performing, including those to the Bio 12 Innovation and Capital Formation Conference, Nebraska Grain Sorghum Board meeting, Nebraska Wheat Board meeting, Nebraska Association of County Extension Boards meeting, Celebration of Youth meeting, the American Hop Convention meeting, Fashion Grou International meeting, Nebraska Research and Innovation Conference, Summer National Graduate School on Eco-Textile Technology meeting in China, Pop Tech Ecomaterials Innovation Lab, and Nebraska Ethanol Board meeting. Because of our leading positions in bio-based fiber researches, I was invited to organize and chair major international conferences and sections of these conferences for a total of 18 times, and 7 keynote speeches. We have submitted a total of 11 patent disclosures to the University and have awarded one US patent. One company, VerseFiber, was formed in Nebraska based on our patented technology. Our inventions were attracted to many companies. We have published a total of 78 referred journal articles, 17 proceeding papers and 1 book chapters. Our researches have been cited more than 1250 times by ISI journals since 2007. PARTICIPANTS: PhD students Current Jiasong Jiang Yi Zhao Helan Xu Graduated Qiuran Jiang Weijie Xu Shah Huda MS students Current Yiling Huang Shaobo Cai Yue Zhang Graduated Wei Li Yi Zou Karlin Helms Wen ang Yean Chin Tan Visiting Scholars Li Shen Xue Jiang Dab Tao Lihong Chen Li Cui Enqi Jin Yan Luo Chunyan Hu Narendra Reddy David Karst Ying Li Taejung Kim TARGET AUDIENCES: Textiles and apparel industries Agricultural and biological engineering firms Agricultural industry Biofuel industry Materials industry Polymer industry Biomaterials industry. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Change in knowledge We are the first to demonstrate that natural cellulosic fibers could be obtained from corn stover, rice straw, sorghum stock, velvet leaves, switchgrass, milkweed stems, hop bines, soybean straws, and the bark of cotton stalks, and the properties of these fibers were similar to other common cellulose fibers. that regenerated protein fibers could be obtained from wheat and soy proteins with properties similar to the natural protein fibers such as silk and wool. that plant proteins could be crosslinked with carboxylic acids without using any toxic chemicals and that the properties of the proteins after crosslinkages, especially their water stability, and tensile properties, could be substantially improved by such crosslinking. that plant proteins and starch acetates may have potential of being used for drug controlled release and tissue engineering. The main materials developed from these biobased materials for medical applications are nanoparticles for drug delivery and fibrous materials as tissue engineering scaffolds. that plant proteins have excellent cytocompatibility and are ideal to be used as the next-generation biomaterials for tissue engineering and therapeutic applications. that using the right ratio of PLLA and PDLA, or adding other polymers to make a polyblend with PLA could produce textile materials with much better resistance to hydrolysis, and therefore making PLA competitive on the textiles market. that nontraditional silks from insects have similar properties to silk worm silk, and have great potential for textile and other applications. that the natural-protein hollow-nanofiber webs produced by weaver ants have excellent properties for the applications in tissue engineering. that via chemical modifications such as acetylation and etherification and via grafting with various acrylates, feathers and and corn distillers' grains could be converted to thermoplastics. that agricultural wastes such as corn stover, chicken quill, and switchgrass stems could be used as reinforcement materials for thermoplastic composites, especially for the light-weight composites. that 100% biocomposites could be formed using cellulosic fibers as reinforcement materials and plant proteins as matrix without using any chemicals as plasticizer. Change in actions and conditions Our findings could allow the PLA producer, Cargill and other companies, to improve the applications of their products in apparels and in the medical industry. Our findings provide important information to researchers and industries for selecting the appropriate renewable resources and application conditions for the development of fibrous materials and non-woven technologies in textiles, composites and medical industries. Our researches on biofibers, in general, allows us the leading position in the area. Our researches attract industries to contact UNL's Office of Technology Development for technology transfers. Our researches on biofibers provide opportunities for Nebraska to add billions of dollars to its economy, add jobs, and for the textile and materials industries to decrease their dependence on petroleum, and increase their sustainability.

Publications

  • Reddy, N., and Yang, Y. 2012. Investigation of the Structure and Properties of Silk Fibers Produced by Actias lunas. Journal of Polymers and the Environment. 20(3), 659-664.
  • Yang, Y., Reddy, N. 2012. Properties and Potential Medical Applications of Regenerated Casein Fibers Crosslinked with Citric Acid. International Journal of Biological Macromolecules. 51(1-2), 37-44.
  • Reddy, N., Jin, E., Chen, L., Jiang, X., and Yang, Y. 2012. Extraction, Characterization of Components and Potential Thermoplastic Applications of Camelina Meal Grafted with Vinyl Monomers. Journal of Agricultural and Food Chemistry. 60(19) 4872-4879.
  • Pan, G., Hou, X., Dong, Z., Zhu, J., Huang, D., and Yang, Y. 2012. Preparation and properties of long wheat straw fibers used for composite. Advanced Materials Research. 476-478, 843-846, February.
  • Huda, S., Reddy, N., and Yang, Y. 2012. Ultra-Light-Weight Composites from Bamboo Strips and Polypropylene Web with Exceptional Flexural Properties. Composites Part B-Engineering. 43(3)1658-1664.
  • Reddy, N.. Jiang, Q., and Yang, Y. 2012. Preparation and Properties of Peanut Protein Films Crosslinked with Citric Acid. Industrial Crops and Products. 39(1)26-30.
  • Yang, Y. and Reddy, N. 2012. Biothermoplastics from Soyproteins by Steaming, Industrial Crops and Products. 36(1)116-121.
  • Chen, L., Reddy, N., Wu, X. and Yang, Y. 2012. Thermoplastic Films from Wheat Proteins. Industrial Crops and Products. 35(1)70-76.
  • Li, Y., and Yang, Y. 2011. Formaldehyde-free chemical and enzymatic crosslinking of plant proteins. Research Journal of Textile and Apparel. 15(4) 1-8.
  • Xu, H. Jiang, Q., Reddy, N., and Yang, Y. 2011. Hollow Nanoparticles from Zein for Potential Medical Applications. Journal of Materials Chemistry. 21(45)18227-18235.
  • Li, Y., Hepperle, S.S., Yang, Y. 2011. Alkali-catalyzed Crosslinking of a New Wheat Gluten Fiber and the Effect of Crosslinking Parameters on Its Mechanical Properties. Research Journal of Textile and Apparel. 15(3) 67-74.
  • Yang, Yiqi; Reddy, Narenda. 2011. Method for making natural cellulosic fiber bundles from cellulosic sources. US Patent 7,887,672 . Feb. 15.


Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: Activities We have successfully developed thermoplastics from feathers and corn distillers' grains via chemical modification and grafting. Our research in this area was broadly reported and raised mush interests in the scientific world. Our research on PLA has been broadened to the comparison of the properties and performance of PLA and PHBV. The main focus is on the applications of these PHAs as tissue engineering scaffolds. Our research on new bio-based non-woven materials has been focused on the development of ultrafine fiber mats from zein for medical applications. More specifically, we have produced biocompatible and water stable zein nonwovens for drug delivery and tissue engineering. We have developed biocomposites using fiber mats from jute and switchgrass as reinforcements and plant proteins, such as zein, soyproteins and wheat gluten as the matrix materials. We have also identified nontraditional natural protein nonwovens made by insects for potential applications in biomedical engineering and other arenas. Events We have reported our findings at 8 national and international conferences, including 2 presentations as keynote speakers. Services We have presented our researches twice to the communities in Nebraska at the Fifth MarketPlace: Opening Doors to Success conference, and to the experts in China. Products We have successfully developed thermoplastics from feathers and corn distillers' grains. We have made novel biocomposites reinforced with nonwoven mats of fibers from agricultural wastes such as switchgrass stems, and matrix materials such as wheat gluten and soyproteins. We have developed novel nonwoven scaffolds from zein for tissue engineering applications. We have discovered the potential application of new natural silk fibers from insects with properties similar to common silks currently available on market. I have graduated one MS graduate student: Wei Li (Biological Systems Engineering, 2009-2011) "Quantitative Analysis of the Reaction between Gliadin and Citric Acid under Weak Acidic and Weak Alkaline Conditions". PARTICIPANTS: Participants from Dr. Yiqi Yang's group Narendra Reddy, Qiuran Jiang, Helan Xu, Yi Zou, Wei Li, Dan Tao, Chunyan Hu, Yan Luo, Xue Jiang, Shaobo Cai, and Enqi Jin. TARGET AUDIENCES: Targeted Audiences textiles, agricultural and biological engineering, materials, polymers, biomaterials. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Change in knowledge We, the first time in the world, have demonstrated that via chemical modifications such as acetylation and etherification and via grafting with various acrylates, feathers and and corn distillers' grains could be converted to thermoplastics. We, the first time in the world, have demonstrated that agricultural wastes such as switchgrass stems could be used as reinforcement materials for thermoplastic composites, especially for the light-weight composites. We, the first time in the world, have developed 100% biocomposites using cellulosic fibers as reinforcement materials and plant proteins as matrix without using any chemicals as plasticizer. We have proven that plant protein nonwoven scaffolds are excellent materials for cell culture and for drug controlled release. We have demonstrated that the natural-protein hollow-nanofiber webs produced by weaver ants have excellent properties for the applications in tissue engineering. Change in actions and conditions Our findings continue to provide important information to researchers and industries for the selecting the appropriate renewable resources and application conditions for the development of fibrous materials and non-woven technologies in textiles, composites and medical industries. Our researches on biofibers, in general, allows us the leading position in the area. This provides us with funds for our graduate education and for our continuing researches. Our researches attract industries to contact UNL's Office of Technology Development for technology transfers. Our researches on the biofibers provide opportunities for Nebraska to add billions of dollars to its economy, add jobs, and for the textile and materials industries to decrease their dependence on petroleum, and increase their sustainability. Importance of the funds The funds from this project were used to pay the students and research associates and to purchase materials and for testing. Without the money from this project, none of the researches could be accomplished.

Publications

  • Hu, C., Reddy, N., Yan, K., and Yang, Y., Acetylation of Chicken Feathers for Thermoplastic Applications. Journal of Agricultural and Food Chemistry. 59(19), 10517-10523(2011).
  • Reddy, N., Hu, C., Yan, K., and Yang, Y., Thermoplastic Films from Cyanoethylated Chicken Feathers. Materials Science & Engineering C-Materials for Biological Applications. 31(8)1706-1710(2011).
  • Reddy, N. and Yang, Y., Potential of Plant Proteins for Medical Applications, Trends in Biotechnology. 29(10)490-498(2011). Reddy, N.. Jiang, Q., and Yang, Y. Novel Wheat Protein Films as Substrates for Tissue Engineering. Journal of Biomaterials Science: Polymer Edition. 22(15), 2063-2077(2011).
  • Reddy, N..and Yang, Y. Novel Green Composites Using Zein as Matrix and Jute Fibers as Reinforcement . Biomass & Bioenergy, 35(8)3496-3503(2011).
  • Reddy, N., Thillainayagam, V., and Yang, Y., Dyeing Natural Cellulose Fibers from Cornhusks: A Comparative Study with Cotton Fibers. Industrial & Engineering Chemistry Research, 50(9), 5642-5650(2011).
  • Reddy, N., Xu, H., and Yang, Y., Unique Natural-Protein Hollow-Nanofiber Membranes Produced by Weaver Ants for Medical Applications. Biotechnology and Bioengineering. 108(7) 1726-1733( 2011).
  • Jiang, Q., and Yang, Y. Water Stable Electrospun Zein Fibers for Potential Drug Delivery. Journal of Biomaterials Science: Polymer Edition. 22(10), 1393-1408(2011).
  • Reddy, N. and Yang, Y., Biocomposites Developed Using Water Plasticized Wheat Gluten as Matrix and Jute Fibers as Reinforcement . Polymer International. 60(4)711-716(2011).
  • Jin, E., Reddy, N., Zhu, Z., and Yang, Y., Graft Polymerization of Native Chicken Feathers for Thermoplastic Applications. Journal of Agricultural and Food Chemistry. 59(5) 1729-1738(2011).
  • Hu, C., Reddy, N., Yan, K., and Yang, Y., Synthesis and Characterization of Highly Flexible Thermoplastic Films from Cyanoethylated DDGS. Journal of Agricultural and Food Chemistry. 59(5) 1723-1728(2011).
  • Reddy, N., Hu, C., Yan, K., and Yang, Y., Acetylation of Corn Distillers Dried Grains. Applied Energy. 88(5) 1664-1670(2011).
  • Hu, C., Reddy, N., Luo, Y., Yan, K., and Yang, Y., Thermoplastics from Acetylated Zein-and-Oil-Free Corn Distillers Dried Grains with Solubles. Biomass & Bioenergy. 35(2) 884-892(2011).
  • Reddy, N. and Yang, Y., Completely Biodegradable Soyprotein-Jute Biocomposites Developed Using Water without any Chemicals as Plasticizer. Industrial Crops and Products. 33(1) 35-41 (2011).


Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: Activities Our research on PLA is focused on care of PLA textiles for consumers, and using PLA for medical applications, specifically for drug controlled release and tissue engineering. Our research on new bio-based fibers included the discovery and characterization of natural silk fibers produced by insects, such as hyalophora cecropia, and saturniidae, for potential textile and medical applications, and on development of fibrous materials from plant and animal byproducts, such as those from milkweed stems, hop bines, wheat straw, starch and its derivatives, feather, and corn, wheat and soy proteins from biofuel production plants, for textiles, composites and medical applications. Events I have given 11 speeches to the people in Nebraska and in the world talking about our researches, which could help the state of Nebraska,and agricultural industry in general. I have also presented 18 papers to major national and international conferences. I have been invited as a keynote speaker for four international conferences to discuss our findings on using agricultural products and byproducts to develop industrial products for a sustainable materials industry and for the value addition to agriculture. Here are some examples of my presentations to the people of Nebraska: Yang, Y., Advances in Textiles and Textile Cares. The Celebration of Youth XVII (Adults 25). October 30, 2010, UNL, Lincoln, NE. Yiqi Yang, Future Fibers and Textiles, for a Course for the Osher Lifeliong Learning Institute at the University of Nebraska-Lincoln, 419 Perspectives on Textiles and Apparel. Rm 121, HECO Building, Lincoln, NE, 8:30-10:00am, April 23, 2010. Yang, Y., Research in Textile Science, 2010 Departmental Research and Education Updates, Webinars presentation for Extension faculty and staff at UNL. March 24, 2010. Yang, Y., Developing green thermoplastics from distillers dried grain. Nebraska Corn Board Meeting, Lincoln, NE. March 23, 2010. Yang, Y., Fabrications of zein nanospheres for potential therapeutic drug delivery applications. Nebraska Corn Board Meeting, Lincoln, NE. March 23, 2010. Yang, Y., Zein nano-fibers and nano-particles for medical applications. Nebraska Ethanol Board Meeting, Lincoln, NE. March 19, 2010. Yang, Y., Innovation in Textiles, presentation to 4H group from Seward County, NE. (10 people) Jan 29, 2010. 1:30-2:30pm. Lincoln, NE. Products We, the first time in the world, have demonstrated that nontraditional silks from insects have similar properties to silk worm silk, and have great potential for textile and other applications. The fibers from plant proteins and carbohydrates are developed in our lab for textiles, composites and medical applications. We have successfully developed ultrafine fibers, one of a thousandth of the width of a human hair, and hollow nanoparticles from plant proteins after biofuel production, and demonstrated that these plant proteins have excellent cytocompatibility and are ideal to be used as the next-generation biomaterials for tissue engineering and therapeutic applications. I have graduated one MS student,Yi Zhou (TCD2007-2010). "Lightweight Composites from Biological Materials and Polypropylene". PARTICIPANTS: Narendra Reddy, David Karst, Weijie Xu, Shah Huda, Qiuran Jiang, Helan Xu, Yi Zou, and Yiqi Yang. TARGET AUDIENCES: textiles, agricultural and biological engineering, materials, polymers, biomaterials. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Change in knowledge We, the first time in the world, have demonstrated that nontraditional silks from insects have similar properties to silk worm silk, and have great potential for textile and other applications. We are the first to demonstrate that plant proteins have excellent cytocompatibility and are ideal to be used as the next-generation biomaterials for tissue engineering and therapeutic applications. Change in actions and conditions Our findings provide important information to researchers and industries for the use of agricultural products and byproducts to make fibers for textile, composite and medical applications. Our research on biofibers allows us lead the researches in the area. This provides us with funds for our graduate education and for our continuing researches. Our researches attract industries to contact UNL's Office of Technology Development for technology transfers. Our researches on the biofibers provide opportunities for Nebraska to add billions of dollars to its economy, add jobs, and for the textile and materials industries to decrease their dependence on petroleum, and increase their sustainability. Our findings could allow the PLA producer, Cargill and other companies, to improve the applications of their products in apparels and in the medical industry. Importance of the funds The funds from this project were used to pay the students and research associates, to purchase materials, for testing, and for research related travels. Without the money from this project, none of the researches could be accomplished.

Publications

  • Jiang, Q., Reddy, N., Yang, Y. Cytocompatible Crosslinking of Electrospun Zein Fibers for the Development of Water Stable Tissue Engineering Scaffolds. Acta Biomaterialia. 6(10) 4042-4051(2010).
  • Reddy, N., and Yang, Y., Non-Traditional Light-Weight Polypropylene Composites Reinforced with Milkweed Floss, Polymer International. 59(7) 884-890 (2010).
  • Reddy, N., and Yang, Y., Structure and Properties of Cocoons and Silk Fibers Produced by Hyalophora cecropia, Journal of Materials Science. 45(16) 4414-4421(2010).
  • Zhou, W., and Yang, Y., Improving the resistance of sulfur dyes to oxidation. Industrial & Engineering Chemistry Research. 49(10), 4720-4725(2010).
  • Reddy, N., and Yang, Y., Light-Weight Polypropylene Composites Reinforced with Whole Chicken Feather. Journal of Applied Polymer Science, 116(6), 3668-3675 (2010).
  • Xu, W., and Yang, Y., Relationship between Drug Release and Some Physical Parameters of Drug Sorption onto PLA Fibers. Journal of Biomaterials Science: Polymer Edition. 21(4) 445-462(2010).
  • Reddy, N., and Yang, Y., Morphology and Tensile Properties of Silk Fibers Produced by Uncommon Saturniidae. International Journal of Biological Macromolecules, 46(4) 419-424(2010).
  • Xu, W., and Yang, Y., Drug Release and Its Relationship with Kinetic and Thermodynamic Parameters of Drug Sorption onto Starch Acetate Fibers. Biotechnology and Bioengineering. 105(4) 814-822(2010).
  • Xu, W., and Yang, Y., Drug Loading onto and Release from Wheat Gluten Fibers Journal of Applied Polymer Science. 116(2) 708-717(2010).
  • Zou, Y., Reddy, N., and Yang, Y., Utilizing Hop Bines as Reinforcements for Lightweight Polypropylene Composites. Journal of Applied Polymer Science, 116(4) 2366-2373(2010).
  • Zou, Y., Huda, S., and Yang, Y., Light-weight composites from long wheat straw and polypropylene web. Bioresource Technology, 101(6) 2026-2033 (2010).
  • Reddy, N., and Yang, Y., Citric Acid Crosslinking of Starch Films. Food Chemistry. 118(3) 702-711(2010).
  • Reddy, N., and Yang, Y., Non-Crosslinked 100% Soyprotein Fibers with High Strength and Water Stability for Potential Medical Applications. Biotechnology Progress. 25(6), 1796-1802(2009).
  • Xu, W., Yang, W., and Yang, Y., Electrospun Starch Acetate Nanofibers: Development, Properties and Potential Application in Drug Delivery. Biotechnology Progress. 25(6), 1788-1795(2009).
  • Huda, S., and Yang, Y., Feather Fiber Reinforced Light-Weight Composites with Good Acoustic Properties. Journal of Polymers and the Environment. 17(2) 131-142(2009).
  • Xu, W., and Yang, Y., Drug Sorption onto and Release from Soy Protein Fibers, Journal of Materials Science: Materials in Medicine. 20(12), 2477-2486(2009).
  • Karst, D., Hain, M., and Yang, Y., Care of PLA textiles, Research Journal of Textile and Apparel, 13(4), 69-74(2009).


Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: Activities Our research on PLA is focused on using PLA for medical applications, especially for drug controlled release and tissue engineering. Our research on new bio-based fibers included the development of natural cellulose fibers from milkweed stems, hop bines, soybean straws, and the bark of cotton stalks, regenerated corn and soy protein fibers from the co-products after ethanol and biodiesel productions, and from starch acetates. We continue our effects on refining the corn DDGS with our main focus on cellulose refinery and characterization. We have also developed a new protein crosslinking method of using carboxylic acids without using any toxic chemicals. This year we have focused our application studies on the development of biobased composites using cornhusks fibers and on tissue engineering scaffold and drug controlled release using fibers from plant proteins, PLA and starch acetates. Events We have reported our findings and researches for a total of eighteen times at the local, national and international meetings. Here are some examples. -Yang, Y. Reddy, N., Li, Y., Jiang, Q., Xu, W., and Yang, W., Some Protein Fibers from Bioenergy Crops. International Conference on Advanced Fibers and Polymer Materials (ICAFPM 2009). Shanghai, china, October 21-24, 2009. Keynote Speech. -Zou, Y., Reddy, N., Huda, Shah, and Yang Y., Developing composites from non-traditional reinforcement materials using non-woven webs, PMSE-384, 237th American Chemical Society National Meeting, Salt Lake City, UT, March 22-26, 2009. -Zou, Y., Reddy, N., and Yang Y., Light-weight composites from hop vines and polypropylene web, CELL-233, 237th American Chemical Society National Meeting, Salt Lake City, UT, March 22-26, 2009. -Yang Y., and Reddy, N., Utilizing cotton stalks as a source for high quality natural cellulose fibers, CELL-205, 237th American Chemical Society National Meeting, Salt Lake City, UT, March 22-26, 2009. -Yang Y., and Reddy, N., Soyprotein fibers for potential use as substrates for tissue engineering,, CELL-160, 237th American Chemical Society National Meeting, Salt Lake City, UT, March 22-26, 2009. -Reddy, N., and Yang, Y., Potential and properties of plant proteins for tissue engineering applications. 13th International Conference on Biomedical Engineering (ICBME 2008), Singapore, December 6-10, 2008. Products We, the first time in the world, have prepared natural cellulosic fibers from milkweed stems, hop bines, soybean straws, and the bark of cotton stalks. We have developed plant protein fibers from corn, soy, and wheat co-products using a new non-toxic crosslinking technology developed in our lab. We have also developed starch acetate fibers. Our work on development of biomaterials for tissue engineering scaffold and drug delivery using plant proteins are fruitful. I have graduated two graduate students, one PhD and one MS: Weijie Xu (5-2009, PhD) Drug Release and Its Relationship with Kinetic and Thermodynamic Parameters of Drug Sorption onto Polylactide, Starch Acetate, Wheat Gluten and Soy Protein Fibers Karlin Helms (8-2009, MS) Low Temperature Non-Toxic Wet Crosslinking of Silk with Citric Acid PARTICIPANTS: Narendra Reddy, David Karst, Weijie Xu, Shah Huda, Qiuran Jiang, Helan Xu, Yi Zou, Chunyan Hu and Ying Li. TARGET AUDIENCES: textiles, agricultural engineering, materials, polymers, biomaterials. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Change in knowledge We, the first time in the world, demonstrated that natural cellulosic fibers could be obtained from milkweed stems, hop bines, soybean straws, and the bark of cotton stalks, and the properties of these fibers were similar to other common cellulose fibers. We also demonstrated that fibers could be obtained from starch acetate. We have demonstrated that cornhusks could be used directly as reinforcement materials for thermoplastic composites, especially for the light-weight composites. We are the first to demonstrated that plant proteins could be crosslinked with carboxylic acids without using any toxic chemicals and that the properties of the proteins after crosslinkages, especially their water stability, and tensile properties, could be substantially improved by such crosslinking. Also, the first time in the world, we have demonstrated that plant proteins and starch acetates may have potential of being used for drug controlled release and tissue engineering. Our work in the next several years will focus on these applications. Change in actions and conditions Our findings provide important information to researchers and industries for the use of agricultural products and byproducts to make fibers for textile, composite and medical applications. Our research on biofibers allow us lead the researches in the area. This provides us with funds for our graduate education and for our continuing researches. Our researches attract industries to contact UNL's Office of Technology Development for technology transfers. Our researches on the biofibers provide opportunities for Nebraska to add billions of dollars to its economy, add jobs, and for the textile and materials industries to decrease their dependence on petroleum, and increase their sustainability. Our findings could allow the PLA producer, Cargill and other companies to develop products for medical applications.

Publications

  • Reddy, N., and Yang, Y., Properties and Potential Applications of Natural Cellulose Fibers from the Bark of Cotton Stalks. Bioresource Technology. 100(14), 3563-3569(2009).
  • Xu, W., Reddy, N. and Yang, Y., Extraction, Characterization and Potential Applications of Cellulose in Corn Kernels and Distillers' Dried Grains with Solubles (DDGS). Carbohydrate Polymers. 76(4), 521-527(2009).
  • Reddy, N., Li, Y. and Yang, Y., Alkali Catalyzed Low Temperature Wet Crosslinking of Plant Proteins Using Carboxylic Acids. Biotechnology Progress. 25(1), 139-146(2009).
  • Reddy, N., Li, Y. and Yang, Y., Wet Crosslinking Gliadin Fibers with Citric Acid and a Quantitative Relationship between Crosslinking Conditions and Mechanical Properties. Journal of Agricultural and Food Chemistry. 57(1), 90-98(2009).
  • Karst, D, and Yang, Y., Method for Predicting Sorption of Small Drug Molecules onto Polylactide. Journal of Biomedical Materials Research Part A. 88A(1), 255-263(2009).
  • Reddy, N., and Yang, Y., Extraction and Characterization of Natural Cellulose Fibers from Common Milkweed Stems. Polymer Engineering and Science. 49(11), 2212-2217 (2009).
  • Reddy, N., and Yang, Y., Preparation and Properties of Starch Acetate Fibers for Potential Tissue Engineering Applications. Biotechnology and Bioengineering. 103(5), 1016-1022(2009).
  • Reddy, N., and Yang, Y., Properties of Natural Cellulose Fibers from Hop Stems. Carbohydrate Polymers. 77(4), 898-902(2009).
  • Huda, S., and Yang, Y., A Novel Approach of Manufacturing Light-Weight Composites with Polypropylene Web and Mechanically Split Cornhusk. Industrial Crops and Products. 30(1),17-23(2009).
  • Reddy, N., and Yang, Y., Natural Cellulose Fibers from Soybean Straw. Bioresource Technology. 100(14), 3593-3598(2009).


Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: Activities Our research on PLA is focused on understanding the relation between PLA structure and its hydrolysis, the optimum application conditions for the better care of the PLA products and developing new fibers with better resistance to hydrolysis. Our research on new bio-based fibers included the development of natural cellulose fibers from velvet leaf and stem, regenerated protein fibers from wheat proteins and corn proteins. Examples of the applications of the new materials developed in our labs were the development of biobased composites using cornhusk fibers and chicken feather as the reinforcement materials. We also start our application of biofibers, mainly plant protein based biofibers for medical applications, such as in tissue engineering scaffold and drug controlled release. Events We have reported our findings at the following meetings: -International Conference on Sustainable Textiles (ICST 08), Wuxi, China, October 21-24, 2008. Keynote Speech. -International Conference on Sustainable Textiles (ICST 08), Wuxi, China, October 21-24, 2008. -The International Conference on Advanced Textile Materials & Manufacturing Technology, Hangzhou, China, October 15-19, 2008. - 235th American Chemical Society National Meeting, New Orleans, LA, April 6-10, 2008. -2008 Symposium of CPBR (The consortium for plant biotechnology research), Washington, D.C., February 11-13, 2008. Services We have presented our researches to the communities in Nebraska, and to the agricultural industries in the country and throughout the world. -The Celebration of Youth XV: Expending Visions. Nov. 1, 2008, UNL, Lincoln, NE. - Fashion Group International, Kansas City Career Day, the Nelson Atkins Museum of Art, Kansas City, MO, November 14th, 2008. - 2008 Nebraska Research and Innovation Conference, the Marriott Cornhusker Hotel, Lincoln, NE. October 28, 2008. (poster) - 14th Legendary Ag Adventure Tour, July 17-19, 2008, Lincoln, Stapleton, Scottsbluff, Harrisburg, Mitchell, Crawford, Kimball, North Platt, Aurora, NE. - 2008 Corn Utilization & Technology Conference (CUTC), June 2-4, 2008, Kansan City, MO. -The American Hop Convention 2008 in Portland, Oregon, January 24, 2008 - Family, Youth, Community Partners. Lincoln, NE. January 11, 2008. - Keynote speaker for the group of Make It with Wool contestants and parents, Nov. 16, 7:30pm, UNL. (24 total) 2007. Products We, the first time in the world, have prepared natural cellulosic fibers from velvet leaves. We have made a novel fiber from the blend of PLA and PP polymers with advantages of both the PLA and PP. We have also developed regenerated protein fibers from wheat and corn proteins. We started the development of biomaterials for tissue engineering scaffold and drug delivery using plant proteins. I have graduated two graduate students, one PhD and one MS: Shah Huda (5-2008, PhD) ~{!0~}Composites from Chicken Feathers and Cornhusk-Preparation and Characterization~{!1~} Yean Chin Tan (12-2007, MS) ~{!0~}Enhancing Properties of Wheat Gluten Fibers by Crosslinking~{!1~} PARTICIPANTS: Participants from Dr. Yiqi Yang~{!/~}s group Narendra Reddy, David Karst, Michelle Hain, Digvijay Nama, Weijie Xu, Teanchin Tan, Abudam Salam, Shah Huda, Wen Yang, and Ying Li TARGET AUDIENCES: textiles, agricultural engineers, materials, polymers, biomaterials. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Change in knowledge We, the first time in the world, demonstrated that natural cellulosic fibers could be obtained from velvet leaves, and the properties of these fibers were similar to other common cellulose fibers, that regenerated protein fibers could be obtained from wheat proteins with properties similar to the natural protein fibers such as silk and wool, and that cornhusk fibers and chicken quill could be used as reinforcement materials for biocomposites. We have demonstrated that using the right ratio of PLLA and PDLA, or adding other polymers to make a polyblend with PLA could produce textile materials with much better resistance to hydrolysis, and therefore making PLA competitive on the textiles market. We also provide the correct laundering information for PLA products first time in the world. Change in actions and conditions Our findings provide important information to researchers and industries for the use of agricultural products and byproducts to make fibers for textile, composite and medical applications. Our research on biofibers allow us lead the researches in the area. This provides us with more than normal funds compare to others in textiles for our graduate education and for our continuing researches. Our researches attract industries to contact UNL's Office of Technology Development for technology transfers. Our researches on the biofibers provide opportunities for Nebraska to add billions of dollars to its economy, add jobs, and for the textile and materials industries to decrease their dependence on petroleum, and increase their sustainability. Our findings could allow the PLA producer, Cargill and other companies to change their production of PLA materials for a better market, especially, the textiles market.

Publications

  • -Xu, W., Karst, D., Yang, W., and Yang, Y., Novel Zein-Based Electrospun Fibers with Water Stability and Strength Necessary for Various Applications. Polymer International. 57(10), 1110-1117(2008).
  • -Li, Y., Reddy, N. and Yang, Y., A New Crosslinked Protein Fiber from Gliadin and the Effect of Crosslinking Parameters on Its Mechanical Properties and Water Stability. Polymer International. 57(10), 1174-1181(2008).
  • -Reddy, N., Tan, Y., Li, Y. and Yang, Y., Effect of Glutaraldehyde Crosslinking Conditions on the Strength and Water Stability of Wheat Gluten Fibers. Macromolecular Materials & Engineering. 293(7), 614-620(2008).
  • -Karst, D, Hain, M., and Yang, Y., Mechanical Properties of PLA after Repeated Cleanings. Journal of Applied Polymer Science. 108(4), 2150-2155(2008).
  • -Reddy, N., Salam, A. and Yang, Y., Effect of Structures and Concentrations of Softeners on the Performance Properties and Durability to Laundering of Cotton Fabrics. Industrial & Engineering Chemistry Research. 47(8), 2502-2510(2008).
  • -Huda, S., and Yang, Y., Chemically Extracted Cornhusk Fibers as Reinforcement in Light-Weight Polypropylene Composites. Macromolecular Materials & Engineering. 293(3), 235-243(2008).
  • -Reddy, N. and Yang, Y., Self-Crosslinked Gliadin Fibers with High Strength and Water Stability for Potential Medical Applications. Journal of Materials Science-Materials in Medicine. 19(5), 2055-2061(2008).
  • -Reddy, N. and Yang, Y, Characterizing natural cellulose fibers from velvet leaf (Abutilon theophrasti) stem. Bioresource Technology. 99(7), 2449-2454(2008).
  • -Huda, S., and Yang, Y., Composites from Ground Chicken Quill and Polypropylene. Composites Science and Technology. 68(3-4), 790-798(2008).
  • -Karst, D, and Yang, Y., Effect of Arrangement of L-lactide and D-lactide in Poly(L-lactide-co-D-lactide) on its Resistance to Hydrolysis Studied by Molecular Modeling. Macromolecular Chemistry & Physics. 209(2), 168-174 (2008).
  • -Reddy, N., Nama, D., and Yang, Y., Polylactic Acid /Polypropylene Polyblend Fibers for Better Resistance to Degradation. Polymer Degradation and Stability. 93(1), 233-241(2008).


Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: Activities Currently, we are working on feathers, corn, soybean, and wheat by-products for fibers and binding materials used in non-woven industry. We also are exploring the possibilities of producing natural cellulosic fibers from all the possible biomass sources, such as corn stover, wheat straw, rice straw, sorghum stock, velvet leaves, and switchgrass. The effect of the structure of various disperse dyes on their percent sorption onto polylactide (PLA) is explained using molecular modeling. The interaction energies between the dyes and PLA have been calculated, and a linear equation has been developed to predict the percent sorption on PLA based on the dye-PLA interaction energy. Events We have reported our findings to the 2007 Autoplast conference (Automotive Composites from Cornhusks Reinforced with Polypropylene; Automotive Composites from Chicken Feather Fibers and Ground Chicken Quill, Mumbai, India. December 12-14, 2007), the American Association of Textile Chemists and Colorists (AATCC) International Conference & Exhibition (Cellulose tendering due to grafting, Charleston, South Carolina, October 2-4, 2007), the 2007 Symposium of CPBR (The consortium for plant biotechnology research) (Biofibers from Proteins in Soymeal and Corn DDGS for Textile and Medical Applications. Washington, D.C., February 12-14, 2007), the Nebraska Wheat Board (Developing composites from natural cellulose fibers obtained from wheat straw. Scottsbluff, NE, June 14, 2007), the Nebraska Corn Board (Extracting high quality Zein from DDGS and developing protein fibers from Zein in DDGS, March 27, 2007, Lincoln, NE), Nebraska Grain Sorghum Board (Natural cellulose fibers and composites from sorghum leaves and stems. University of Nebraska-Lincoln. March 6, 2007), the annual meeting of AATCC Midwest Section (Nontraditional biofibers for a new textile industry, The Town Hall, Atlas Material Testing Technologies, Chicago, IL, April 20, 2007) and to three Universities in China. Products We, the first time in the world, have made regenerated protein fibers from wheat gluten and natural cellulosic fibers from corn stover, rice straw, sorghum stock, velvet leaves, and switchgrass. We have made a novel fiber from the blend of PLA and PP polymers with advantages of both the PLA and PP. We have two patent applications Natural cellulosic fiber bundles from cellulosic sources and a method for making the same. United States Patent Application 2007199669. August 30, 2007 Process for the production of high quality fibers from wheat proteins and products made from wheat protein fibers.United States Patent Application. 20060282958. December 21, 2006 Three students, two PhDs and one MS, have graduated David Karst (12-2006, PhD) Studies on the Stability and Intermolecular Interactions of Cellulose and Polylactide Systems Using Molecular Modeling Narendra Reddy (12-2006, PhD) Structure and properties of natural cellulose fibers from cornhusks, cornstalks, rice, wheat and soybean straws and sorghum stalks and leaves Digvijay Nama (12-2006, MS) Novel Synthetic Fibers From Polylactic Acid (PLA) / Polypropylene (PP) Blends PARTICIPANTS: Shah Huda David Karst Ying Li David McAlister III (USDA Cotton Quality Research Station, Clemson, SC) Abdus Salam Narendra Reddy Weijie Xu Wen Yang YiqiYang TARGET AUDIENCES: Agriculture Bioengineering Biomaterials Textiles Composite Biopolymers Fibers Food Environment

Impacts
Change in knowledge We, the first time in the world, have demonstrated that wheat gluten could be used to make protein fibers with mechanical properties similar to wool and appearance similar to silk. We, the first time in the world, have demonstrated that natural cellulosic fibers could be obtained from corn stover, rice straw, sorghum stock, velvet leaves, and switchgrass, and the properties of these fibers were similar to other common cellulose fibers. We have demonstrated that adding PP(polypropylene) to PLA can increase the resistance of PLA to hydrolysis and retain the advantages of PLA. The predicted percent sorption for a dye on PLA from molecular modeling is shown to agree with its experimentally obtained percent sorption on commercial PLA fabric and on PLA fiber extruded in our laboratory. Change in actions and conditions Our researches provide important information to researchers and industries for the use of agricultural products and byproducts to make fibers for textile, composite and medical applications. Our work on preparation and characterization of wheat gluten fibers was the most accessed paper in Biomacromolecules, one of the best biopolymer journals in the area. Our research on biofibers allows us lead the researches in the area. This provides us with more than normal funds compare to others in textiles for our graduate education and for our continuing researches. We have attracted industries to contact UNL's Office of Technology Development for technology transfers. Our researches in the biofibers provide opportunities for Nebraska to add billions of dollars to its economy, add jobs, and for the textile and materials industries to decrease their dependence on petroleum, and increase their sustainability. Our work is included as one of the major impacts in the category of Agriculture, Food Production, and Natural Resource Systems in the Executive Summary (page XV), and in the major report (pages 66-71) in "A generator of Positive Economic Impacts for Nebraska" by Batttelle, February 2007; is one of the 25 researches featured in the 2006-2007 Annual Report (page 17), Office of Research & Graduate Studies, University of Nebraska-Lincoln; is selected as one of a few major reviews of research achievement in 2006-2007 academic year by the Scarlet Year in Review 2006-2007.(8-3007. P. 7). Our research on developing fibers from wheat gluten was featured by American Chemical Society as the top third article from their 34 research journals in their News Service Weekly PressPac (press package)- Jan. 24, 2007. Many major news agencies throughout the world also reported our work on biofiber development this year, indicating the interests in our work from the public and the potential importance of our results to the world. Here are a few examples of various reports Time, Apparel Takes Root, 3-1-07 New York Times, Science Times, A Wheat-Based Wool? D3, 2-6-07 Bioenergy Pack, Bioeconomy at work: Protein fibers from wheat gluten, similar to wool, 1-30-07 Science Daily, Spinning Wheat: New Fibers Have Mechanical Properties Similar To Wool, 1-30-07 Audubon, Fashionable Waste, p16, 1-2, 2007.

Publications

  • -Reddy, N. and Yang, Y., Development and Characterization of Long Natural Cellulose Fibers from Wheat Straw. Journal of Agricultural and Food Chemistry. 55(21), 8570-8575(2007). -Huda, S., Reddy, N., Karst, D., Xu, W., Yang, W., and Yang, Y., Nontraditional Biofibers for a New Textile Industry, Journal of Biobased Materials and Bioenergy. 1(2), 177-190, 2007.
  • -Xu, W., Reddy, N. and Yang, Y., An Acidic Method of Zein Extraction from DDGS. Journal of Agricultural and Food Chemistry, 55(15), 6279-6284(2007).
  • -Reddy, N., Yang, Y and McAlister III, D. D., Processability and Properties of Yarns Produced from Cornhusk Fibers and Their Blends with Other fibers. Indian Journal of Fibre & Textile Research. 31(4), 537-542, December, 2006.
  • -Karst, D, and Yang, Y., Effect of Structure of Large Aromatic Molecules Grafted onto Cellulose on Hydrolysis of the Glycosidic Linkages. Macromolecular Chemistry & Physics. 208(7), 784-791(2007).
  • -Reddy, N. and Yang, Y., Natural Cellulose Fibers from Switchgrass with Tensile Properties Similar to Cotton and Linen, Biotechnology and Bioengineering, 97(5) 1021-1027(2007).
  • -Reddy, N. and Yang, Y., Structure and Properties of Natural Cellulose Fibers Obtained from Sorghum Leaves and Stems. Journal of Agricultural and Food Chemistry, 55(14), 5569-5574(2007).
  • -Reddy, N. and Yang, Y, Structure and Properties of Chicken Feather Barbs as Natural Protein Fibers, Journal of Polymers and the Environment, 15(2), 81-87(2007).
  • -Karst, D, Nama,D. and Yang, Y., Effect of Disperse Dye Structure on Dye Sorption onto PLA Fiber. Journal of Colloid and Interface Science. 310(1), 106-111(2007).
  • -Reddy, N., Salam, A. and Yang, Y., Effect of Lignin on the Heat and Light Resistance of Lignocellulosic Fibers. Macromolecular Materials and Engineering. 292(4), 458-466(2007).
  • -Salam, A., Reddy, N., and Yang, Y. Bleaching of Kenaf and Cornhusk Fibers. Industrial & Engineering Chemistry Research. 46(5), 1452-1458 (2007).
  • -Reddy, N. and Yang, Y, Novel Protein Fibers from Wheat Gluten, Biomacromolecules, 8(2), 638-643 (2007).(It was the top 14 most accessed articles of Biomacromolecules, Jan-March, 2007 http://pubs.acs.org/journals/bomaf6/promo/most/most_accessed/2007q1.h tml)
  • -Yang, Y., V. Naarani and V. Thillainayagam, Color Repeatability in Inkjet Printing, AATCC Review, 7(1), 45-48(2007).
  • -Yang, Y., and Naarani, V., Improvement of the lightfastness of reactive inkjet printed cotton, Dyes and Pigments, 74(1), 154-160 (2007).
  • - Reddy, N. and Yang, Y, Properties of High Quality Long Natural Cellulose Fibers from Rice Straw. Journal of Agricultural and Food Chemistry. 54(21), 8077-8081(2006).


Progress 10/01/05 to 09/30/06

Outputs
Molecular modeling has been used to explain how the blending of poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) affects the resistance of poly(lactide) (PLA) to hydrolysis. Amorphous PLLA/PDLA blends were created using molecular modeling, and the minimum potential energy of the blends before and after hydrolysis were obtained. The 50/50 blend has the greatest resistance to hydrolysis, which agrees with past experiments and is due to its having stronger hydrogen-bonding and dipole-dipole interactions than pure PLLA or PDLA. This is based on the 50/50 blend having more of these interactions and shorter average lengths for the hydrogen-bonds and dipole-dipole interactions compared to pure PLLA and PDLA. Hydrogen-bonding possibly has a greater effect than the dipole-dipole interactions on the resistance to hydrolysis. The change in potential energy for hydrolysis decreases linearly with increasing % PLLA or % PDLA from 0 to 50%. Grafting various groups onto cellulose is found to substantially increase acid hydrolysis of the Beta-(1,4)-glycosidic linkages. Molecular modeling is used to explain how various substituents such as esters and ethers cause this phenomenon. A substituent helps stabilize hydrolyzed cellulose by serving as an anchor to the end of the cleaved cellulose to which it is bonded, making it less mobile, and allowing it to have stronger interactions than those in pure hydrolyzed cellulose. Hydrolysis increases with increasing size of the substituent. Molecules sorbed but not grafted to cellulose do not increase hydrolysis. Hydrolysis mainly occurs at glucoses bonded to the substituent, and supporting experiments show that hydrolysis approaches equilibrium when no substituent remains on the cellulose fiber. The structure and properties of novel long natural cellulose fibers obtained from rice straw are studied. Rice straw fibers have 64% cellulose with 63% crystalline cellulose, strength of 3.5 grams per denier (450 MPa), elongation of 2.2% and a modulus of 200 grams per denier (26 GPa), similar to that of linen fibers. The rice straw fibers reported here have better properties than any other natural cellulose fiber obtained from an agricultural byproduct. With a worldwide annual availability of 580 million tons, rice straw is an annually renewable, abundant and cheap source for natural cellulose fibers. Using rice straw for high value fibrous applications will help to add value to the rice crops, provide a sustainable resource for fibers and also benefit the environment.

Impacts
Our study on hydrolysis mechanisms of PLA provides insights on improving the resistance of PLA to hydrolysis. This provides guidance to the making of new PLA with controlled hydrolysis, which is critical to the use of PLA in textiles, plastics, composites, and medical application. We are the first in the world to explain the accelated hydrolysis of cellulose due to grafting. Our explaination add an important information to the cellulose chemistry and provide theoretical background for the understanding of the durability of chemically modified cellulose materials.Our findings also provide information for the increase of the yield of glucose through cellulose hydrolysis. Such an information is critical to the increase in ethanol yield from biomass. We have developed,the first time in the world,natural cellulose fibers from rice straw. Such an invention could add billions of dollars to rice production, decrease the demand on foreign oils for our fiber needs, and decrease the pollution from burning rice straws.

Publications

  • - Reddy, N. and Yang, Y. 2006. Properties of High Quality Long Natural Cellulose Fibers from Rice Straw. Journal of Agricultural and Food Chemistry. 54(21), 8077-8081.
  • -Karst, D., Yang, Y, and Tanaka, G. 2006.An Explanation of Increased Hydrolysis of the -(1,4)-Glycosidic Linkages of Grafted Cellulose Using Molecular Modeling. Polymer, 47(18), 6464-6471.
  • -Karst, D., and Yang, Y. 2006. Molecular modeling study of the resistance of PLA to hydrolysis based on the blending of PLLA and PDLA, Polymer, 47(13), 4845-4850. -Karst, D., and Yang, Y. 2006. Potential advantages and risks of nanotechnology for textiles, AATCC Review, 6(3), 44-48.
  • -Yang, Y., Naarani, V., Thillainayagam, V., and Reddy, N. 2006. Effects of printhouse humidity and temperature on quality of ink jet printed cotton, silk and nylon fabrics, Journal of Imaging Science and Technology, 50(2), 181-186.
  • -Yang, Y., Han, S., Fan, Q., and Ugbolue, S.C., 2005. Nanoclay and modified nanoclay as sorbents for anionic, cationic and nonionic dyes, Textile Research Journal, 75(8), 622-627.
  • -Zhou, W., Reddy, N. and Yang, Y., Overview of protective clothing, in Textiles for protection, Scott, R.A. ed., The Textile Institute & Woodhead Publishing, Cambridge, England, CRC Press, NW, USA, 2005, pp.3-30.
  • -Yang, Y. and Reddy, N.,2006. High quality and long natural cellulose fibers from rice straw and method of producing rice straw fibers. United States Patent Application. 20060180285. August 17, 2006
  • -Yang, Y., Naarani, V. and Thillainayagam, V, 2005. Color repeatability in inkjet printing, 2005 Book of Papers--AATCC International Conference & Exhibition, American Association of Textile Chemists and Colorists, Research Triangle Park, NC, pp. 201-207.
  • -Reddy, N., and Yang, Y., 2006. Characterizing chicken feather barbs as natural protein fibers. PMSE (Polymeric Material Science and Engineering) Preprints , 95 946-947. Publisher: American Chemical Society, Division of Polymeric Materials: Science & Engineering.
  • -Reddy, N. and Yang, Y., 2006. High quality 100
  • - Salam, A., Reddy, N., and Yang, Y., 2005. Influence of some commercial softeners on the properties of cotton fabrics, 2005 Book of Papers--AATCC International Conference & Exhibition, American Association of Textile Chemists and Colorists, Research Triangle Park, NC, pp. 209-216.
  • -Reddy, N., and Yang, Y., 2005. Alternative fibers from agricultural byproducts for textiles, 2005 Book of Papers--AATCC International Conference & Exhibition, American Association of Textile Chemists and Colorists, Research Triangle Park, NC, pp. 284-290.


Progress 10/01/04 to 09/30/05

Outputs
The arrangements of L-lactide and D-lactide in poly(L-lactide-co-D-lactide) copolymers that give polylactide improved resistance to hydrolysis are found using molecular modeling. Amorphous structures of these copolymers were created, and molecular dynamics simulations and energy minimizations were run to calculate their potential energies before and after hydrolysis. The interaction energies between the L-lactide and D-lactide segments and between themselves were studied, and their effect on hydrolysis of the copolymers were explained. The effect of nanoclay on dye sorption was investigated for potential use in PLA to improve its dyeability and to decrease its hydrolysis during dyeing. Nanoclay has excellent sorption of anionic and nonionic dyes, much better than any fibers currently available on market. The study indicated that it is possible to use nanoclay in PLA fiber to improve the dye uptake of PLA, and perhaps to decrease the hydrolytic damage to the fiber due to dyeing. The potential advantages and possible disadvantages of using nanotechnology for textiles were explored.

Impacts
The better resistance of PLA to hydrolysis and the better dye sorption behavior of PLA are critical to the successful application of this biodegradable synthetic polymer in textiles. The application of PLA in textiles will add value to Nebraska and US agricultural products and perhaps byproducts, move the textile and fiber industry away from the current heavy reliance on petroleum.

Publications

  • -Karst, D., and Yang, Y. Potential advantages and risks of nanotechnology for textiles, AATCC Review, accepted 2005.
  • -Yang, Y., Naarani, V., and Thillainayagam, V. Effects of printhouse humidity and temperature on quality of inkjet printed cotton, silk and nylon fabrics, Journal of Imaging Science and Technology, accepted 2005.
  • -Yang, Y., Han, S., Fan, Q., and Ugbolue, S.C., Nanoclay and modified nanoclay as sorbents for anionic, cationic and nonionic dyes, Textile Research Journal, accepted 2005.
  • - Karst, D., and Yang, Y., Using the solubility parameter to explain disperse dye sorption on PLA, J. Appl. Polym. Sci., 96(2), 416-422(2005).
  • -Karst, D., and Yang, Y., Improving the resistance of polylactide to hydrolysis based on the arrangement of L- and D-lactide in poly(L-lactide-co-D-lactide). PMSE (Polymeric Material Science and Engineering) Preprints. American Chemical Society, Division of Polymer Chemistry, NY, NY. 93 775-776 (2005).


Progress 10/01/03 to 09/30/04

Outputs
Objective 1. To improve the processing and performance properties of PLA fibers. The focus of this year is on improving the dye exhaustion on PLA, understanding the effect of monomer structures, L- and D-lactic acids, on the resistance of the PLA fiber to hydrolysis and the effect of home laundering conditions on mechanical property retention of the PLA fabrics. The solubility parameters of PLA, PET, and various disperse dyes were used to explain the low exhaustion of disperse dyes on PLA but the high exhaustion of those dyes on PET. It was found that dyes with high exhaustion on PLA tended to have low solubility parameters, which corresponds with the fact that the solubility parameter of PLA is lower than that of PET. It was also found that the solubility parameter, calculated based on data at 25C, was more appropriate for explaining dyeings at lower temperature than at higher temperature, 130C. Based on the finding that dyes with low solubility parameters tend to have high exhaustion on PLA, we proposed other existing dyes and new dye structures that may have high exhaustion on PLA. The configuration of polylactide that provides greater resistance to hydrolysis was determined through molecular modeling simulations. Polylactide is a polymer known for its biodegradability, which is useful for certain applications. However, for materials requiring greater stability of the polymer, the high susceptibility of polylactide to hydrolysis is a concern especially at high temperatures and alkaline conditions. The configuration of the L and D-isomers of lactic acid along the polylactide chain are known to affect its properties. In this study, molecular modeling simulations were used to create amorphous structures of polylactide that consisted of various arrangements of L and D-polymers in the amorphous structure. Molecular dynamics simulations followed by energy minimizations were performed to calculate the energy of the structures before and after hydrolysis. The structures with a greater resistance to hydrolysis were proposed. The effects of home laundering conditions on tensile properties of PLA fabrics were investigated. Examples of these conditions are laundering temperature, pH and drying conditions, such as machine drying under different conditions and air drying. The results of up to 50 home launderings were obtained. The appropriate care instructions for the PLA materials with consideration on the high retention of strength and elongation of the textiles after laundering were recommended. Objective 2. To develop a new method of making high quality PTT fibers with compatible prices using 1,3 PDO from the agricultural industry in Nebraska. No activities this year.

Impacts
Our findings on the relation between disperse dye structure and dye exhaustion on PLA provides guidance to the selection of appropriate dyes for the dyeing of PLA. This information will provide savings in dyeing, decrease in dye discharge to the effluent, and improvement in colorfastness of this new fiber. Our study in laundering conditions of PLA provides guidance to the care of this new material, and affects the value of PLA textiles directly. Our fundamental study on PLA molecular structures and their impact on resistance of the material to hydrolysis provide information on making the PLA resins with high resistance to hydrolysis. Easy hydrolysis is the major problem preventing PLA from large scale applications in area where easy hydrolysis should be avoided. The work supported by this grant added key information to the very limited public knowledge of PLA materials.

Publications

  • Karst, D., and Yang, Y., An explanation and prediction of disperse dye exhaustion on PLA, 2004 Book of Papers--AATCC International Conference & Exhibition, American Association of Textile Chemists and Colorists, Research Triangle Park, NC, 2004, pp. 184-188.
  • Karst, David; Yang, Yiqi. Improving the resistance of polylactide to hydrolysis based on the configuration and arrangement of the molecules. Polymer Preprints, 45(2), 614(2004).
  • Karst, D. and Yang, Y., Improving the resistance of polylactide to hydrolysis based on the configuration and arrangement of the molecules. POLY-215, Book of Abstracts, 228th American Chemical Society National Meeting, Philadelphia, PA, August 22-26, 2004, (Abstract).
  • Karst, D., and Yang, Y., Effect of L- and D-isomers of lactic acid on the resistance to hydrolysis of polylactide fibers., Spring 2004 International Symposium on Fibers, Fibrous Structures and Filtration, The Fiber Society, St. Louis, MO, May 18-20, 2004 (Abstract).
  • Hain, M., Influence of laundering and drying parameters on PLA fabrics, MS Theses, University of Nebraska-Lincoln, Lincoln, NE 68583 USA. May, 2004


Progress 10/01/02 to 09/30/03

Outputs
Objective 1 To improve the processing and performance properties of PLA fibers The relation between PLA fabric processing conditions and the effect of fabric processing on fabric mechanical properties were investigated. Our study found that using the normal dyeing conditions, PLA could lose 40 percent of its strength and 20 percent of its breaking elongation in dyeing. This study provided the initial information on mechanical properties of PLA in textile processing. It showed to the industry that careful processing, and perhaps novel processing is necessary for the production of PLA containing materials. It also raised questions to the PLA manufacturers to improve the properties of PLA materials, specifically, the resistance to hydrolysis in textile processing. The comparison of disperse dye exhaustion, color yield, and colorfastness between PLA and PET are also performed. It was found that only two out of the ten dyes examined had exhaustions higher than 80 percent. Fiver out of the ten dyes had exhaustion less than 50 percent at 2 percent dye concentration based on the weight of the fabric to be dyed. This study found that the color yield of PLA was 30 percent higher than that of PET, meaning that PLA looked 30 percent darker than PET if both adsorbed the same amount of a dye. A quantitative relation between the shade depth of PLA and PET based on their dye sorption was developed. This study also found that disperse dyes examined had lower washing and crocking fastness on PLA than on PET. Light fastness of PLA and PET dyed with disperse dyes was similar. Objective 2. To develop a new method of making high quality PTT fibers with compatible prices using 1,3 PDO from Nebraska's agricultural industry. No activities this year.

Impacts
Our work discovered a major problem of PLA fabric currently in use. The knowledge from our research will guide the industry for their processing of PLA materials. It also suggested that different textile processing conditions should be considered for this new material. Our research also provided a fundamental understanding of the dyeing behavior, color yield and colorfastness of this new fiber. The work supported by this grant added very important information to the very limited public knowledge of PLA textiles.

Publications

  • Yang, Y., and Huda, S., Dyeing conditions and their effects on mechanical properties of polylactide fabric, AATCC Review, 3(8), 56-61 (2003).
  • Yang, Y., and Huda, S., Comparison of disperse dye exhaustion, color yield, and colorfastness between polylactide and poly(ethylene terephthalate), J. Applied Polym Sci., 90, 3285-3290 (2003).


Progress 10/01/01 to 09/30/02

Outputs
objective 1. To improve the processing and performance property of PLA fibers. Dyeing conditions for PLA, such as temperature, pH, ramping rate and holding time were investigated from the viewpoint of a dyer. Eleven disperse dyes were used for this study, based on their popularity, different energy levels, chemical constitutions, and pH sensitivities. With considerations to % dye exhaustion, color consistency, levelness, and mechanical property retention of the fiber, an industrial applicable PLA (polylactide) dyeing procedure was proposed. This study disclosed the relations among dyeing conditions, quality of dyeing, and the mechanical properties of the fiber after dyeing. The information from this research provides a guidance to the textile industry, and provides a research direction to the polymer and textile scientists for the future improvement of the PLA fibers. Objective 2. To develop a new method of making high quality PTT fibers with compatible prices using 1,3 PDO from Nebraska's agricultural industry. We haven't done any work on making the new PTT fiber. However, work on characterizing dyeing behaviors of PTT was performed. The dyeing behaviors of PTT/PET blends were investigated. Influence of dyeing time and temperature on dye uptake was examined. The effect of blend levels on the quality of the dyed goods, such as dye uptake, shade depth, and colorfastness, was explored. Dyeing conditions for different blend levels of PTT/PET are recommended. Due to the strong disperse dye affinity and the atmospheric dyeability of PTT, PTT/PET mixtures were pattern colored in a single dyebath with only disperse dyes. Possible approaches to such pattern coloring and examples of the cross dyeing results are also discussed. The color quality of the dyed PTT/PET blends is very close to the 100% PET. The improved fabric performance properties and the disperse cross dyeing ability provide this new product with some novel opportunities. Sorption characteristics, such as sorption kinetics and isotherms, relation between dye sorption and shade development of PTT and their comparison with PET, were reported. Results from two different dyeing rate studies, dyeing rate under constant temperature and under changing temperature, were examined to obtain the common rate constants and to obtain information for the design of dyeing temperature profile and holding time. Rate constants of PTT were compared with that of PET. Sorption isotherms of disperse dyes on PTT were also studied. Both Nernst and Langmuir models were examined. The dye uptake ability of PTT was compared with PET.

Impacts
The information from this research provides a guidance to the textile industry, and provides a research direction to the polymer and textile scientists for the future improvement of the PLA and PTT fibers. The information from both objectives obtained by the PI and his co-workers were the major research results in the literature of these two new fibers.

Publications

  • Yang, Y., Brown, H., and Li, S., Some sorption characteristics of poly(trimethylene terephthalate) with disperse dyes, J. Appl. Polym. Sci. 86(1), 223-229(2002).
  • Yang, Y., Li, S., Brown, H., and Casey, P., Dyeing of PTT/PET Blends, AATCC Review, 2(8) 54-59(2002).
  • Yang, Y., and, Huda, S., The balance between dyeing and physical properties of PLA, 2002 Book of Papers--AATCC International Conference & Exhibition, American Association of Textile Chemists and Colorists, Research Triangle Park, NC, 2002, pp. 196-202.
  • Yang, Y., Li, S., Brown, H., and Casey, P., Batch Dyeing of PTT/PET Blends with Disperse Dyes, 2001 Book of Papers--AATCC International Conference & Exhibition, American Association of Textile Chemists and Colorists, Research Triangle Park, NC, 2001, pp.291-297.