Duration: 10/01/2001 to 09/30/2006

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Project's Primary website is at http://msa.ars.usda.gov/la/srrc/csrees/main.htm (direct link can be found under LINKS)

The U.S. textile industry is a world leader in manufacturing textiles, employing more than 600,000 people in nearly every state and generating $69 billion annually (113). In order for the U.S. textile industry to maintain its leadership and competitive edge while preserving the environment, new technologies are needed to convert agricultural residues and by-products into textile products and to enhance the technical performance of conventional textiles for new consumer, medical and industrial applications. This new millennium project focuses on expanding the uses for agricultural commodities and by-products, investigating more environmentally friendly methods for textile processing utilizing biotechnologies, and developing novel, high performance textile products for specialty applications. The research proposed herein is not duplicated by any of the other 139 Regional Research Projects listed at http://www.msstate.edu/org/saaesd/cris/reproj.htm; furthermore, NC-170 focuses primarily on protective clothing. It also is broader in scope and compliments some of the related projects listed under the USDA-ARS program area of Quality and Utilization of Agricultural Products.

Justification: The textile industry today is concerned with five main interrelated issues: procurement of raw materials, converting them into finished products, meeting customer expectations, and human health/environmental safety, and making a profit. Many of these issues parallel the priorities developed by the ESCOP, e.g., the environment, sustainable production systems, economies of rural communities, and consumer interests. There also is a need to develop new materials and composites and new manufacturing technologies for making textiles that are more "environmentally friendly." Finding alternative raw materials, synthetic pathways, natural processes, and reaction conditions are central to EPAs mission and have been endorsed by former president Clinton since 1995.

Justification for Developing Value Added Products from Renewable/Recyclable Resources

The U.S. agriculture accounts for -
20% of the GNP through the production of agricultural raw materials and products. The agriculture industry also contributes $40 billion annually in exports with each billion resulting in -
30,000 jobs. However, oil imports continue to drain our economy and account for -
20% of our trade deficit. At the same time, the world's plant biomass is about 2,000 billion tons, and the renewable resources amount to about 100 billion tons/year (68). Given the abundance of biomass feedstocks, the value added to the U.S. economy, and potential reduction in the trade deficit, it seems logical to pursue the use of biomass for production of materials and chemicals. Furthermore, considering the four million tons of post-consumer textiles waste generated annually, the rising cost of disposal, reduction in available space, and increasing environmental concerns, research is critically needed on innovative recycling technologies for textile wastes.

Since the introduction of nylon in the1940s, synthetic fibers have had a significant impact on the quality of our lives. However, the demand for natural fibers continues to increase because of their many outstanding properties, including aesthetics, comfort, and biodegradability. Research efforts are refocusing on exploring alternative fiber crops, crop residues, and agricultural by-products, which are often underutilized. For example, kenaf fibers are environmentally friendly, easy to grow, and adaptable to many soil types. AES scientists in AR, GA, LSU-LA, and TN (3, 13, 14, 28, 80, 90-92) are investigating kenaf because of its economic potential for fiber producers as well as the cottage craft industries in AR and other states with significant craft industry-based economies. However, before kenaf can become a viable crop, new value-added products must be developed to prove its versatility in the textile, apparel, and craft industries. Work by scientists in AR, KS, and MS (18-20, 82-83) has resulted in the production and manufacturing of a variety of kenaf products for both apparel and home furnishing uses. Because of the worldwide interest in kenaf, hemp, jute, and other alternative crops, work is needed to further enhance its aesthetics and properties for a wider range of products through bleaching, dyeing, and finishing. These research efforts will facilitate the use of kenaf in various types of value added products for the craft industry.

Similarly, agricultural residues and by products from major U.S. agricultural commodities (sugarcane, soybeans, wheat, corn, etc.) could be used to produce a multitude of value-added non-food products, ranging from fibers, films, plastics, and composites to resins, finishing agents, and auxiliaries. Furthermore, many of the chemical compounds used for textile wet processing are currently obtained from petrochemicals and could also be derived from agri-chemicals.

Sugarcane is an important agricultural crop in LA and FL. FL producing is the largest U.S. producer of sugarcane with a crop value of $472 billion (53.2% of the total), followed by LA with a crop value of $287 billion (30.4%). Most of the crushed stalks (bagasse) currently produced are used as in-house fuels in mill processing and for other low value applications, such as mulch and ceiling tiles (75). Development of value-added products from the waste or low-value materials could allow mills to migrate to cleaner burning fuels and provide economic benefits to sugarcane producers. Researchers in LSU-LA have developed processes for converting bagasse into textile and geotextile products (19-20). The development of higher value-added products would create new uses and provide economic benefits for both LA and FL.

About 22% of the textile fibers produced are used for industrial applications, which includes low and high resin composites (113). However, the abundance of recyclable fiber and agricultural residues, coupled with the dwindling supply of some natural resources, have created the need to develop alternative structural composites. Researchers in KS, NE, and LSU-LA (30, 34, 39) have been exploring the use of agricultural residues and byproducts from wheat, soybeans, and bagasse for textile applications and low and high resin composites. Agri-plastics and composites appear to be the most promising use for many of these crop residues. However, many challenges exist in identifying market segments, determining performance requirements, selecting resins, and optimizing manufacturing properties. Attempts to manufacture agri-fiber composites have been impeded by finding suitable resins that parallel the quality of wood-based particleboards made with formaldehyde-based resins. Fundamental research is needed on evaluating the flow properties and manufacturing conditions to maximize the use of agri-plastics in toys and other consumer applications.

Work also is being done on making solvent- spun cellulosics from cheaper raw materials, such as agricultural wastes (e.g., bagasse and wheat straw) or post consumer cellulosic textiles (rayon and cotton and their blends). Obtaining fiber-forming cellulose solutions (lyocell) from reclaimed cellulosics or agricultural wastes has become important topic for researchers in LSU-LA, KS, and TN (15, 21, 22, 69). Likewise, researchers in TN in conjunction with Cargill first produced spun-bonded

and melt-blown nonwovens with good strength, cover, and hand properties from polylactide derived from the by-products of the fermentation of corn. Further work is needed on exploring other nonfood uses of agricultural residues.

Justification for Bio-Processing and Related New Technologies for Textile Applications

Developing environmentally safer methods for processing textiles can be done with biological systems, rather than conventional chemistries. Historically, enzymes have been used for the retting of bast fibers and desizing of grey goods. In the last decade, enzyme systems have been developed for bioscouring and antipilling cellulosics and for imparting anti-felting properties to wool (9). New frontiers in biotechnology for textile processing include cross-linking of polymer chains to impart easy-care properties, and enzyme surface modification to enhance absorption/dyeing and aesthetic properties. Another approach to reducing the use of energy, chemicals, and time in textile processing is dual or multi-purpose dyes and finishing agents. KS is developing a dual purpose, dye-insect control agent produced by linking together a reactive dye with insect growth regulators. This technology would help reduce the $1 billion annual loss due to insect attack.

Rapidly progressing, new technologies require innovative materials for a large variety of applications. Optimizing both the bulk and surface properties of various materials represents one of the promising approaches for meeting the technical and economical requirements for high-tech materials. Because of the cost related to developing new fibers, polymer chemists now focus on modifying existing fibers to impart the desired aesthetic or functional properties. Conventional fiber modification methods include various thermal, mechanical, and chemical treatments. Another important means of modifying the fiber to increase the uptake of dyes and finishes or to impart unique functionality is through plasma technology (102-104). The reactive species of plasma, resulting from ionization, fragmentation, and excitation processes, are high enough to dissociate a wide variety of chemical bonds, resulting in a significant number of simultaneous recombination mechanisms. Plasma syntheses opens up new possibilities for polymer chemistry, particularly in industrial applications where the specific advantages of producing pore-free, uniform thin films of superior physical, chemical, electrical and mechanical properties have been required.

The main advantages of plasma polymerization methods are: 1) applicability to almost all organic, organo-metallic and hetero-atomic organic compounds, 2) modification of surface properties without altering the bulk characteristics, 3) low quantities needed of monomeric compounds making it non energy intensive, and 4) wide applicability to most organic and inorganic structures. Exciting applications in polymer chemistry include 1) cold plasma discharge synthesis of new polymeric structures, 2) plasma induced polymerization processes, 3) surface grafting of polymers, and 4) surface modification of polymers. Characteristics that can be improved include wettability, flame resistance, adhesive bonding, printability, electromagnetic radiation reflection, surface hardness etc.

Justification for the Development of Textiles for Protective/Medical Applications

Specialty textiles contribute to human health, safety, and comfort by protecting people from exposure to heat, chemicals, pesticides, pathogens in blood and body fluids, and electromagnetic radiation. AES researchers continue to focus on developing textile systems for human health and safety. Two important requirements for protective medical apparel are barrier effectiveness and comfort for the wearer. Depending on the end-use, different characteristics are required to achieve the optimum barrier efficiency. The effectiveness of protective apparel worn by patients and health care workers continues to be a major concern because of the risks of infection when the protective apparel fails. The risks are especially great with the spread of HIV and other infectious diseases. OSHA estimates that more than 5.6 million health care/public safety workers are at potential risk of being exposed to HIV and hepatitis B. Centers for Disease Control [CDC], the Association of Operating Room Nurses [AORN], and the Occupational Safety and Health Administration [OSHA]) have published guidelines for health care workers to minimize exposure risks. OSHA mandates that health care workers wear personal protective equipment that meets specified performance levels (25).

Another major health concern is the increasing incidence of skin cancer caused by exposure to sunlight. Skin cancer is the most common form of cancer in the U.S., resulting in -
9,000 deaths annually. Both acute and cumulative exposure to solar radiation, especially UV-B radiation (280-315 nm), can result in sunburn, aging, immune-suppression, and skin cancer. The risk of developing skin cancer can be greatly reduced by minimizing exposure or by using protective apparel. The challenge for textile scientists is to develop summertime fabrics that are both comfortable and provide adequate protection. Work is needed to elucidate the relationship between the chemical structure of dyes and their UV-absorbing properties, and how the UV-absorption of fabrics is influenced by end-use conditions (light, laundering, and wear). Researchers in KS, NE, TN, and TX (24, 109, and 123) are interested in the influence of polymer additives (delustrants, UV absorbers, and fluorescent whitening agents) on the UVR transmission of fabrics. Work is needed to answer the question of whether the type of water (distilled, sea, or pool water) influences UV transmission. A predictive model is needed that interrelates the influence of fiber, yarn, and fabric characteristics on UPF of fabrics. Doctors (KU Medical Center) have requested information on the relationship between fabric and apparel characteristics that will provide adequate UV protection. Such information would be beneficial to doctors when counseling patients on preventive measures for reducing the risk of skin cancer.

Justification for Developing and Evaluating Textiles with Enhanced Resistance

(or Susceptibility) to Environmental Degradation

Heat, light, atmospheric contaminants, weathering, microorganisms, and insects are some of the major environmental agents that can attack and degrade textiles during wear, use, or storage. For many end-use applications, resistance to these environmental agents is desirable. However, one or more of these degrading influences may be targeted when designing textiles that are environmentally degradable. S-272 researchers have examined many aspects of environmental degradation related to enhancing the resistance or susceptibility, depending on the product end-use and requirements.

Related, Current and Previous Work

Our former Regional Project S-272, Development of Textile Materials for Environmental Compatibility and Human Health and Safety (terminates 9/30/2001) resulted in numerous publications cited herein and at our web site (http://msa.ars.usda.gov/la/srrc/csrees/main.htm). The proposed research focuses on developing value-added products from agricultural fibers, residues, and by-products, especially those having multi-state importance to the participating states. Greater emphasis will be placed on developing a) textile products from renewable and recyclable resources and b) textile processing methods utilizing enzymatic and plasma treatments. Work will continue on assessing the environmental compatibility of selected and newly developed materials and their suitability for specific end-uses, including consumer products and medical/protective textiles. Equipment, experimental methods, processing technologies, and expertise relative to the synthesis, extraction, and processing of agri-fibers, previously developed through S-272 project, will be utilized and expanded upon in this proposed multi-state-project as reflected in the current and previous work..

Development of Value Added Products from Renewable/Recyclable Resources

The diversity of resources for this objective result in a concentration of cooperative efforts under sub-objectives, embracing novel ideas for making products from renewable and recyclable materials.

New Lyocell and Composite Fibers and Fabrics Derived from Biomass. The earliest commercial method for manufacturing regenerated cellulosic fibers (rayon) from delignified wood chips is the viscose process, which is complex and environmentally-polluting. Today, solvent-spun cellulosic fibers (lyocell) are being produced from more environmentally benign solvents. A major limitation of these new lyocell fibers is fibrillation under wet abrasion conditions. The formation of lyocell fibers from N-methyl morpholine N-oxide monohydrate, NMMO.H₂O, solutions in conditions allowing a tailored fibrillation is currently being investigated at KS, LA-LSU and TN (22). This is achieved by controlling rheological parameters in the liquid crystalline phase preceding fiber formation (77, 78) or by using an electrical discharge (cold plasma) radio frequency technique, developed by WI and LSU-LA. Work also has been done on spinning lyocell fibers from kenaf, steam exploded bagasse, and wheat straw (81, 92). Negulescu et al. (70) have proposed a scheme to separate the cellulosic component from PC blends from which lyocell fibers can be spun.

A new area of interest is biosynthetic polymers, such as polylactide polymers (PLA), produced by Dow-Cargill from corn-derived lactic acid. These polymers can be processed by melt fabrication methods (61). Morphological transformation of PLA fibers/fabrics during the application of disperse dyes have been recently presented by LSU-LA investigators (60).

Non-food Applications of Agricultural By-products and Residues for Textiles and Composites. Agriculture production generates residues in the form of cereal straw, corn stover, sugarcane bagasse, etc., while the production and consumption of soft goods generate billions of pounds of fiber and textile residues. Attention has been drawn to converting these agri-residues and consumer wastes to textiles, composites, paper pulp, and other consumer and industrial products. KS researchers have investigated the use of tocopherols to reduce photo-degradation in fibers and soy proteins as fillers in thin plastics films (39). More recently, Gatewood, Ramaswamy, et al. (35) have focused on adding value to agri-composites through bleaching, dyeing, and controlling particle size. An H₂O₂ bleaching system with an acetic acid rinse substantially improved the whiteness of the straw. Major limitations of straw board that need to be addressed are poor moisture resistance and adhesion with formaldehyde-based resins because of the waxy cuticle. Ramaswamy et al. (30) investigated the use of straw and kenaf as fillers in plastics or high resin composites. The agri-fibers and resins were ground into specified particle sizes, extruded, chopped into pellets, and hot pressed into thick plastic sheets, then exposed to heat, light and weathering. Work is needed on the processing and properties of other agri-fibers, by-products, and residues, or recyclable materials for composite applications.

Development of Degradable Cotton-core Nonwovens. Cotton, a renewable resource, has many properties that are most suitable for constructing absorbent nonwoven products. Preparation of nonwovens made of biomass PLA or polyesterimide at TN could make the cotton-core products completely biodegradable and further increase consumer appeal (47, 67). Cotton-core nonwovens will be elaborated in the following sections related to the use of biodegradable hygiene products.

Development of Kenaf Value-added Products for Textiles and Crafts. The Kenaf Demonstration Project was started in 1986 with cooperation from USDA and Kenaf International. Its primary goal was to make the kenaf industry a reality in the U.S. (New Multi-state Project Development Committee DC-95-06). Today, kenaf is a market-ready commodity used in making paper, cordage, fabric blends, etc. (80, 82, 83). Much work has been done on fiber preparation to facilitate the utilization of kenaf in value-added products. Research is needed to introduce kenaf to the craft industry for producing various types of value-added products - baskets, hats, etc. Hence, kenaf could have a formidable influence on craft industry in AR and other states.

Development of Industrial Textile Products from Sugarcane Fibers. Researchers at LSU-LA, FL, and TN (13, 14, 18-20) have focused on developing products from sugarcane for commercial use in geotextiles and other industrial applications. This integrated project, involving states producing almost 85% of the U.S. sugarcane, exemplifies the development of mill-to-market, bio-based, value-added products. Work has been done at LSU-LA on delignification, cellulose extraction, and fiber processing methods. Results indicated that atmospheric extraction can be used and steam explosion omitted with higher alkaline concentrations (91). A pilot scale reactor was constructed at LSU-LA to bring the process closer to commercial production conditions. Preliminary results have demonstrated that sugarcane rind, mechanically separated from the stalks, can be chemically and mechanically treated to extract the valuable cellulosic fibers.

Bagasse erosion control mats have been produced and tested against existing commercial products. These mats were comparable in performance to commercial wood, straw, and coconut products and had better water, light, and flame resistance than other commercial products (111, 112). The bagasse and coconut fiber mats also biodegraded at approximately the same rate. Significant advantages of the bagasse mats were 1) stitching was not needed because of fiber entanglement and 2) ability to conform to the contours of the soil, preventing washout. Preliminary work on bleaching and dyeing of sugarcane fiber have been carried out (90). The geotextile erosion control market is an area of expected growth. The development of other value-added products from bagasse will result in economic development at the local, national, and international levels.

Development of Bio-Processing and Related New Technologies for Textile Applications

The overall objective in this multi state research project is to utilize relatively new surface enhancing technologies to improve the processibility, functionality, and aesthetics of fabrics. Research activities in this objective address three important areas related to purifying and enhancing the characteristics and appearance of textiles: 1) bioprocessing, 2) plasma application, and 3) digital printing.

Recent advances in biotechnology have given the textile industry new auxiliaries (enzymes) for wet processing (9). Sarkar and Etters (94-97) have extensively studied the biopreparation of cotton and enzyme kinetics using alkaline pectinases. Other enzymes used in biopreparation of cotton are amylases for desizing and cellulases to enhance the surface characteristics (smoothness). Ramaswamy et al. are studying the use of enzymes for biofinishing kenaf and kenaf/cotton blends. Proprietary treatments have resulted in dramatic increases in the whiteness, appearance, and hand. Similarly, protein disulfide isomerases are commercially available for improving the shrinkage behavior of wool (103). Work by Buschle-Diller (8) at AL investigated the effectiveness of five proteases from plant and microbial sources on wool fabrics. KS is focusing on developing enzymatic methods for purifying/biofinishing of wool and specialty hair fibers using xylanases and pectinases. Gatewood and Ramaswamy (36) have shown that the wool subjected to chlorination and isomerases was less prone to insect attack. The surface properties of enzyme-treated fabrics have been studied by Ramkumar (85) using a simple sliding friction apparatus to objectively quantify the enhancement.

Research on modifying the surface characteristics of polymers/fibers using plasma technology has been the focus of research by Sarmadi et al. (26, 27, 31-33, 49, 50, 101-104) at WI s Plasma Research Institute. Plasma modification methods serve as a pivotal contribution to the research work at the other contributing institutions in this project. These studies have shown new demands for syntheses of special property plasma polymeric layers, through the incorporation of additional elements, such as various metals. Studies carried out at WI have demonstrated that low electron energy (20-30 eV) MS spectrometry of plasma monomers can offer valuable data in this field.

Development and Evaluation of Textile Systems for Protective and Medical Applications

A relatively new area of textile development has been the design, production, and evaluation of textile systems for protecting individuals from chemicals, heat, harmful electromagnetic radiation, and high-speed impact (air bags and bullet-proof vests). Recent studies by AU, NE, and KS have focused on quantifying the degree of UV protection afforded by textile materials and in identifying the various factors that affect it. These states have the expertise and instrumentation for determining UPF values for textiles. Many parameters influence a fabrics UV transmission. NE and KS (24, 109) have generated databases of UPF values for a range of fiber and fabric types. Recent work by Crews et al. has shown that fabric porosity is the best predictor of UV blocking properties, and polyester, silk, and wool fabrics exhibited better UV blocking properties than cotton or rayon. Zhou and Crews (123) demonstrated that detergents with optical brighteners improved the UV blocking ability of fabrics. Srinivasan and Gatewood (109) investigated the influence of 95 dyes on the UV protection provided by cotton and nylon fabrics and the relationship between chemical constitution and UV absorption. Most of the dyes caused a substantial reduction in the UV transmission, and the reduction was linear with concentration up to a point. The interpretation of the absorption spectra of the dyes with respect to their chemical structure indicated that in most dyes, UV absorption depended on specific structural attributes rather than the chemical class to which they belong. Work is needed on how environmental conditions (water and light exposure) and other additives influence UV transmission.

Previous studies by WI (88, 89, 98-100), TN, GA (51-58) and KS (64) have addressed the barrier properties of textile substrates for human health and safety. Fabric penetration and worker contamination depend on the fiber chemistry, yarn/fabric construction, surface treatments, and environmental conditions. Growing concern about HIV and other infectious diseases attributed to blood borne pathogens has resulted in the development and testing of the barrier properties of textiles to fluids and microorganisms. Many medical textiles do not have adequate barrier properties to effectively protect medical personnel from pathogens. Sarmadi et al. (88, 89) and Leonas and Huang (52, 55, 58) have shown that fabrics treated with low surface tension liquids (fluorochemicals) have enhanced barrier properties. They (7, 53, 54-57) also have identified parameters critical to barrier properties, e.g., fabric surface chemistry, fabric geometry, challenge liquid, and organism properties. The complex nature of fabrics resulted in many challenges for investigators. Advances in microscopy technology have provided insight into transmission mechanisms. Researchers at GA evaluated the mechanism of small particle transmission necessary to develop new fabrics with suitable barrier properties using Laser Scanning Confocal Microscopy. Work continues on developing moisture permeable fabrics that provide barriers to liquids and microorganisms. Other studies by Cloud et al. (11, 12) have focused on the comfort of protective apparel by objective and subjective methods. Correlations were found between objective and subjective data, comfort and barrier efficiency, and specific fabric characteristics. As new materials are developed, comfort assessment is critical.

Development of Textiles with Enhanced Resistance

(or Susceptibility) to Environmental Degradation

The term "sustainability" has been adopted to convey the realization that our environment is more favorably served by conserving resources, be it by improving the durability of textiles, making materials more biodegradable, or recycling of plastics or fabrics. For example, reclaiming the cellulosic component from a polyester-cotton blend would provide an excellent source for the production of the more environmentally friendly fiber, lyocell. Negulescu et al. (69) proposed a process for separating the cellulosic component from blends from which lyocell fiber can be spun.

Researchers at KS and WI are focusing on the biological resistance of wool. A recent study (36) has shown that most wool and specialty hair fibers are readily attacked by webbing clothes moth and black carpet beetle larvae, but the extent of degradation is influenced somewhat by animal type, fiber fineness, and chemical treatments. With the elimination of dieldrin and the potential ban on other insecticides (59), research is needed on alternative methods of insect control. Current work at KS and WI is evaluating multifunctional reactive dyes and plasma treatments for imparting insect control.

New biosynthetic polymers, such as PLA polymers and some copolyesters are easily synthesized from renewable resources via fermentation from carbohydrate-rich material, such as food industry by-products (dairy wastes and potato peels). PLA polymers are bio-/hydro-degradable and offer a broad balance of functional performance, making them suitable for many applications. They are expected to compete with hydrocarbon-based thermoplastics on a cost/performance basis.

Cotton has many outstanding properties suitable for constructing effective capillary control in absorbent nonwovens. Internal microscopic pore spaces of cotton contribute to its ability to swell during the transition from the dry to the wet state. The excellent absorbency and water retention properties of cotton-core laminates with melt-blown polypropylene webs have been demonstrated (65, 117), but these nonwovens are not biodegradable. Nonwovens made of PLA (47) or polyesterimide (67) at TN could further expand the use of cotton in the large absorbent cores market and make the products completely biodegradable to further increase consumer appeal.

Objectives

1. 
   

Methods

This multifaceted research agenda requires the intense cooperative efforts among the participating states because each has unique facilities and faculty expertise. For example, KS, LSU-LA, TX, WI, and TN are on the forefront of product development. Researchers at AL, AU, FL, AR, GA, and NE have the expertise in characterizing fabrics and evaluating functional performance and environmental compatibility. The above objectives can only be accomplished through cooperative research studies, and 11 states have pledged their support and participation. The broad spectrum of scientific/technical expertise offered by the participating states is of the highest caliber and includes textile chemistry, agricultural value-added product development research, fabrication including nonwoven and composite manufacturing, environmental sciences, entomology and environmental toxicology, and accelerated and in-service studies. Many different crops and fiber sources, processing facilities, and textile testing equipment are needed to accomplish the above objectives. No single university alone has the resources required to develop end-products and processing methods or evaluate the characteristics or properties of the textile materials and composites proposed herein. Also, the funding required to accomplish such broad and comprehensive research objectives is substantial. Therefore, RRF funding is required and necessary.

Objective #1: To Develop Value Added Products from Renewable and Recyclable Resources

New Lyocell and Composite Fibers and Fabrics Derived from Biomass. Investigations on lyocell fibers, fabrics and composites will continue at LSU-LA, TN, KS, and WI in the following areas with the technical support from SRRC: 1) lyocell fibrillation, 2) producing lyocell from agrifibers and consumer wastes, 2) developing biomass-derived polyhydroxylated nylons, 3) preparation of lyocell composites with PLA and polyhydroxylated nylons, and 4) alteration of surface properties of lyocell fibers and fabrics prepared in 2) and 3) by reactive plasma. In some instances, fibrillated-spun lyocell has advantages in making nonwovens, e.g., aesthetics and hydro-entanglement. It is envisioned that lyocell (woody), bagasse, or wheat straw fibers spun from NMMO/water solutions can be easily transformed into nonwovens. For example, specialty nonwovens can be obtained by cellulose derivatization, and ion exchange materials for filtration can be prepared by reacting lyocell bagasse fibers with cationic/anionic compounds suitable for removing reactive dyes and heavy metals from industrial wastewater.

Polyhydroxylated polyamides (PHPA) obtained from biomass carbohydrates are promising candidates for making nylons. NMMO monohydrate also may be a good solvent for PHPA. Unique molecular composites can be formed by co-solving PLA or PHPA in a lyocell solution. Current research at LSU-LA is preparing molecular composites based on PHPA/lyocell solutions (68-71). The rheological behavior of the lyocell solutions prepared by common research protocols at KS, TN, LSU-LA will be used to predict the processability and effects of impurities (e.g., lignin). Thermal stability and crystallization temperatures will be determined by DSC, TGA, dielectric relaxation, and thermo-gravimetry measurements.

Sarmadi at WIs Plasma Research Center will coordinate the methodology and treatments for surface modifications of fibers and materials to enhance functional properties. The plasma-created surface layers of synthetic and natural fabrics, films and composites will be investigated at other participating institutions by ATR-IR, ESCA, AFM, surface wettability, and dyeability. Data collection and analysis will be coordinated by WI. This will represent one of the most comprehensive integrated studies on plasma treatment of natural and synthetic materials.

Non-food Applications of Agricultural By-products and Residues for Textiles and Composites.

Researchers at AL, KS, and LSU-LA will focus on developing agri-boards and composites from agri-residues, alternative bast fibers (kenaf and bagasse), and recycled fibers. Comparative research will be done on the surface chemistry and morphology of fibers for composite application and its influence on bonding. The goal is to develop agri-boards with better internal bonding and moisture resistance, which are major market limitations. KS and LSU-LA will develop disposable and durable plastic products with renewable carbohydrate-based fillers and gypsum. For each filling system, formulas with promising properties will be prepared for tensile testing using injection-molding (2) at optimum molding temperatures, pressures, and cooling conditions, then further evaluated for stability. KS and LSU-LA will develop standard board/composite preparation methods and testing protocols, which will facilitate collective data analysis.

Mechanical and chemical surface treatments will be done to enhance bonding. The lignocellulosic will be subjected to five defibrillation techniques [acids, alkalis, thermo-chemical, organic solvents, and enzymes]. All plasma treatments will be done at WI; and KS and WI will investigate the surface changes. Alternative resins systems to be explored are phenolics and epoxies in conjunction with coupling agents. The experimental, hot pressed composites will be tested using the facilities in KS. Surface functionalities and bonding at the lignocellulosic-resin interface will be evaluated by XPS, AT-IR, and SEM. Thermal phase transitions, mechanical properties, morphology, and water absorption will be evaluated for specified temperatures, humidity, light, and storage time exposures. The resistance of the agri-boards to water, weathering, insects, and microorganisms will be done at KS, GA, and LSU-LA using standard AATCC and ASTM test methods to facilitate cooperative data analysis (1, 2).

Recently, WI has started work on plasma treatment of starch to produce new plastics. The advantage of plasma treatment over conventional methods to incorporate starch and other renewable resources is that since the plasma modifies only the surface of starch molecules, the bulk properties are unchanged, insuring biodegradation of the new product. Likewise, treated surface of starch produce a much stronger bond with other monomers, preventing phase separation. LSU-LA, in conjunction with WI and TN, is studying the thermal behavior of the new plastics with promising results (62).

Development of Degradable Cotton-core Nonwovens. Cotton Inc. has sponsored research at TN on developing cotton-core nonwovens (CCN) for diapers and hygiene products. CCNs have been made by sandwiching cotton cores containing from 50:50 cotton/PP to 100% cotton between two thermally bonded melt blown (MB) PP webs, two spun bonded (SB) PP webs, or between a MB and SB web. These CCNs have excellent wicking and absorbency properties, but are not totally biodegradable. Hence, MB webs will be produced from PLA, PEA and copolyester resins, then thermally bonded to cotton webs. Optimal bonding conditions will be determined for CCNs containing cotton cores ranging from 15-100 g/m² and with outer layers of PLA, PEA, copolyester, and PP webs weighing 10-30 g/m². Biodegradability will be determined at WI. Hand properties of the nonwovens will be evaluated at TX using methods developed by Ramkumar (86-87). As in the previous regional project, the melt-blown facilities at TN are unique and necessary for preparing all of the nonwoven samples used by other participating states.

Development of Kenaf Value-Added Products for Textiles and Crafts. Researchers at LSU-LA and SU-LA will continue collaborative research on improving kenaf yarns for apparel applications. Kenaf fiber will be extracted from raw kenaf currently growing at SU using bacterial and chemical retting methods, then spun into kenaf/cotton yarns on ring or rotor spinning frames. The blended yarns and fabrics will be mercerized at LSU using NaOH or ammonia and characterized using ASTM standards and the KES-FB instruments (2, 106). AR will focus on developing value-added craft products from kenaf cultivar, Everglades 41. After processing, the fibers will be hand-carded and spun to develop methods suitable for ARs craft industry.

Development of Industrial Textile Products from Sugarcane Fibers. FL, TN, and LSU-LA will further develop value-added products from bagasse fibers. Specific research objectives are: 1) to compare fibers extracted from different sugarcane varieties in FL and LA, 2) to develop needle-punched nonwoven mats and spun yarns, and 3) to investigate the effects of different treatments on the dyeability. The sifted bagasse will be treated with NaOH and carded with other cellulosic fibers to form mats. Fiber blending properties will be measures on the Kawabata Pure Bending Tester using a method developed by Collier et al. (23). Other parameters to be measured are the effectiveness of the carrier fibers in processing and increasing mat strength, length variability between the blended fibers, optimum fiber weights, and the effects of fiber processing lubricants. The carded fiber webs will be further processed into slivers and spun into yarns after determining optimum spinning conditions. Yarn properties will be measured and correlated with fiber length, tex, and bending properties. Yarn characteristics also will be related to web formation method and carding machine type. FL will study the dyeing behavior using reactive and direct dyes, followed by colorfastness testing (2). Because of their expertise, researchers at LSU-LA and TN will coordinate data collection/analysis on sugarcane product development and provide input on other projects on value added product development.

LSU-LA, TN, and KS will continue to study the use of agricultural fibers (sugarcane, kenaf, cotton, flax, ramie, etc.) and recycled polymer materials for making nonwovens. Specific objectives include 1) the development of methods for separating the polymer/fiber from industrial remnants, 2) processing the fibers into nonwovens, and 3) determining effective approaches to improving end-use performance of nonwovens. New approaches to recycling natural and synthetic polymers will be investigated. Recycled fibers will be blended and carded to form fiber webs, then needle-punched to form nonwovens. SRRC (38) will assist in developing finishing methods to improve end-use performance. The prototype nonwovens developed will be prepared using TNs unique facilities.

Objective #2: To Develop Bioprocessing and Related New Technologies for Textiles

Research related to bioprocessing and other new technologies for textile applications will be restricted to the application of enzymes to cellulosic and protein fibers, plasma surface treatments to modifying the functional properties of fibers, and newly emerging technologies related to coloration. Participating states will cooperate in the selection, application, and evaluation of the enzyme treatments to facilitate collective data analysis. However, individual states will focus on specific fiber types. AL will focus on developing one-bath processes for desizing/scouring/bleaching cotton using enzymes (8). Potential advantages include less water usage, energy consumption, and fiber damage, making this process attractive. Amyloglucosidases will be used for desizing because they produce the most glucose from starch; and pectinases from different organisms will be investigated for bioscouring. Glucose produced during scouring/desizing can be converted into H₂O₂ for bleaching by glucose oxidase enzymes, making it possible to reuse treatment baths. Enzymes selection will be based on compatibility in their active pH/temperature ranges. TX also will continue to investigate the use of neutral enzymes found in the environment to achieve a softer hand on resin-treated cotton fabrics. The goal is to achieve fabrics that have a wrinkle-free effect with improved softness and hand. Enzyme kinetic studies will be done at CO. The treated cotton fabrics will be characterized for whiteness, mechanical properties, and surface changes. Important parameters in evaluating the effectiveness of bioprocessing methods are changes in hand and appearance. Most of the hand evaluation studies on enzyme-treated fabrics will be performed at TX using a sliding friction method developed by Ramkumar (85-87). This method is able to discriminate among fabrics treated with different levels of cellulase enzymes, which typically exhibit lower friction values and improved hand.

KS will continue developing bioprocessing methods for scouring wool and specialty hair fibers (camel, llama, alpaca, cashmere, mohair, and rabbit). Proteases, typically used for bioscouring, can cause fiber degradation. Removal of waxes/skin particles may be more effectively done by pectinases and xylanases without degrading proteins. Research will focus on developing enzymes systems and optimum conditions of pH, time, and temperature. Fiber characteristics to be evaluated include strength, length/width, and topography and chemical changes using SEM and FT-IR spectroscopy.

AL, WI, and KS scientists will evaluate the surface characteristics and chemistry of the processed wool and specialty hair fibers. Additionally, the dye affinity studies will provide answers to the consumer related properties. Dyes selected will depend on the chemical classes of the dye and the chemistry of fibers. Wool fibers also will be used in spinning/weaving/knitting trials to evaluate the quality of fibers and fabrics produced. The spinning/weaving/knitting trials will be done at the SRRC/USDA or TX.

Researchers at WI and TX will investigate the influence of the following plasma treatments on the structures, surface properties and deposition rates in plasma-generated layers: 1) RF power dissipated the electrodes or inductive coil, 2) pressure in the system in the absence of plasma, 3) pressure in the reactor during the plasma process, 4) reaction period, 5) pressure variations during the deposition reactions, 6) temperature of the substrate, and nature of RF coupling. Plasma treated fabrics from WI will be supplied to TX for the evaluation of surface and hand-related properties.

One of the most recent developments in textile coloration is digital printing because of its many advantages, e.g., speed, fine line detail, energy savings, and rapid design change (29). Most digital printing systems for textiles are currently being used to print samples rather than products. Work is needed on developing digital printing systems that meet consumer and industry standards for depth of shade and fastness properties (1, 2). SU-LA will investigate digital printing methods for different fiber types (cellulosic, protein, and synthetic fibers) using different ink types (reactive dyes for cellulosics, disperse dyes for synthetics, and acid dyes for protein fibers) and fixation methods. Plasma-treated fabrics from WI also will be printed to examine the effects of various surface modification on affinity, depth of shade, and fastness to light, weathering, crocking, and laundering (1). Hand measurements for all treated fabrics will be done using Kawabata instruments at LSU-LA.and the surface friction method at TX.

Objective #3: To Develop and Evaluate Protective and Medical Textile Systems

Research will focus on developing textiles that provide protection against UV radiation and blood borne pathogens, and the comfort assessment of these products. AU, KS and NE will continue to evaluate the influence of dyes, UV absorbers, and finishes on the UV transmission properties. KS and NE have identical Perkin Elmer UV/visible spectrophotometers for evaluating UPF, making them unique in their ability to coordinate test protocol and data analysis. Gatewood and Crews also participated in the initial meetings of RA106 that developed AATCC Test Method183 (1) for evaluating UPF. Previous work was limited to direct and reactive dyes on cotton and acid and disperse dyes on nylon fabric. KS has shown that some vat dyes are strong UV absorbers (109). Hence, future work will focus on vat dyes on cotton, disperse and basic dyes on acrylic fabrics, and pigment colorants for PP because of their widespread use for outdoor fabrics. The dope-colored polypropylene nonwovens will be spun bonded at TN. Secondly, selected colorants with high UV absorption will be applied in conjunction with UV absorbers to determine synergistic effects. Previous research at KS and NE focused on woven fabrics. Future work will characterize knitted fabrics in terms of porosity, yarn construction, gauge, and finishes to determine the construction parameters effecting UV transmission values. Lastly, a predictive model will be developed based on cumulative data to provide a mathematical model for manufacturers to use in selecting fabrics and creating apparel with optimum sun protection. Researchers at FL will assess the comfort properties of the fabrics that provide improved sun protection, based on subjective and objective components.

GA will continue to examine the mechanisms of particle and liquid transmission through textile based surgical protective clothing and equipment, and parameters that influence transmission, e.g., fiber size, fabric geometry, surface characteristics and finishes, such as antimicrobial treatments. This information will aid in the development of fabrics that meet the OSHA standards and have the desired characteristics for the specified end-use. Pore size/distribution will be measured using an Automated Perm Porometer (1); pore geometry will be assessed by SEM and confocal microscopy. The liquid barrier properties will be measured by ASTM F 1670 and F-1862 (2); and the antibacterial properties will be measured according to AATCC Test Methods 100 and 147 (1) using microorganisms causing hospital-acquired infections. The thermal comfort properties of the fabrics developed for medical uses also will be evaluated by FL researchers to better understand the relationship between barrier properties and perceptual and physiological responses of the body. Comfort properties will be assessed based on the body temperatures of human subjects in an environmental test chamber.

Research in AL will focus on developing intelligent, stimuli- sensitive fibers and fabrics (SSP) that change their character or regulate performance properties in a desirable manner when the surrounding environment changes (115). Fibers developed from these polymers or made from existing fibers coated with SSPs will be investigated in terms of possible applications. Natural chitosan polymers have promising potential for SSPs. Grafting or UV-curing technologies will be applied to these polymers to introduce constituents. The goal is to reduce response times for phase transitions under controlled conditions. Practical uses include time release of drugs, temperature regulation in exercise clothing, robotic muscles, and temperature sensors. Researchers participating in the subtopics outlined above will cooperate in fabric selection, research protocol, and collective data analysis.

Objective #4: To Develop and Evaluate Textiles with Enhanced Resistance

(or Susceptibility) to Environmental Degradation

Researchers working on Objective 4 are driven by the common goal of "sustainability," recognizing that the environment is better served by conserving resources through improving the durability, making it more biodegradable, or by recycling. AR researchers will develop unique nonwoven needle- punched composites containing recycled PET and PP blended with kenaf and cotton to enhance biodegradability. These needle-punched nonwovens will be prepared at SRCC, LSU-LA, and TN and subjected to soil burial tests for 2-16 weeks, then evaluated for changes in physical properties (thickness, weight, strength, and color change). Microscopic examination will be used to determine types of and amounts of fungal growth.

Totally biodegradable cotton-based nonwovens will be prepared at TN using MB webs of PLA, PEA, and Eastar Bio-copolyester. Processing conditions will be optimized to produce the finest fibers with each resin. Similar weight webs of 100% PP also will be made for comparison. Physical tests will include weight, thickness, bursting strength, air permeability, and flexural rigidity using ASTM and AATCC test methods (1, 2). GA will determine the porosity and contact angles of the MB webs and composites with a PMI instrument and Chan Dynamic Contact Angle tester, respectively. Degradation of the nonwoven webs will be determined at WI and AR using ATCC Test Method 30 (1). Other important end-use tests to be done at TN are the Harnett and Mehta's Transverse Wicking Plate Test (40) and the absorbency and water retention capacity tests (109).

KS will focus on determining how dye fading during light exposure reduces the UPF of fabrics. It is well known that UV and visible radiation can cause a chemical change and loss in color because of the changes in visible absorption, but little is known about how light exposure change the absorption of UV-A and UV-B radiation. Cotton and nylon fabrics dyed with selected direct, reactive, and vat dyes or disperse and acid dyes, will be exposed to xenon radiation following the procedures in AATCC Test Method 16 (1), simulating outdoor exposure, then evaluated for changes in the UPF values.

Since DDT and dieldrin have been banned by EPA, only a limited number of insect resist agents are available commercially. Because of the potential hazards of insect-resist agents, two alternative methods will be explored in KS. The first approach is to develop dual purpose reactive dye that have both coloration and insect resist capabilities. The reactive dyes used for synthesis will contain two reactive groups. One group (e.g., a monochlorotriazine) with an R = -NH₂ group will be reacted with a -COOH group on a potential pesticide moiety to form a -CO-NH- (amide) linkage, which is found in protein fiber. It is anticipated that the amide group can be hydrolyzed in the insect gut to release the insecticide moiety. The most likely compounds are chlorinated aromatics, some of which resemble dye chromaphores. Jones et al. (45) developed fiber-reactive derivatives of organophosphorus compounds, which was deemed a new approach, but a literature review reveals no attempt to make a dual purpose reactive dye. The dual-purpose dyes will be applied to wool fabrics using conventional dyeing procedures for reactive dyes (59). Cold plasma treatment will be done at WI to impart functional groups, such as CN, and SiClx in addition to grafting other chlorinated aromatic groups on the surface of wool and specialty hair fibers to increase insect-repellence. Different power, pressure, flow rate and treatment time will be used to achieve a condition, which provides the maximum insect-repellence. Using plasma to impart insect repellence is a novel approach that reduces air, water and land pollution in comparison to conventional methods of wet chemistry. This novel treatment promises to extend the useful life of consumer textiles and apparel by enhancing insect resistance. The insect resistance of the experimental compounds will be evaluated against webbing clothes moths and black carpet beetles according to AATCC Test Method 24 (1). All insect testing will be done at KS because it has one of the few labs currently able to do insect testing.

As shown in Table 2, most of the states will be participating in more than one research objective, and each research objective has multiple state participants. This is crucial for this unique interdependent project requiring specific facilities housed at only one or perhaps two participating institutions, e.g., nonwoven facilities (TN), plasma center (WI), UPF equipment (KS and NE), confocal microscopy (GA), friction testing (TX), fiber extrusion equipment (LSU-LA and KS), printing equipment (SU-LA and KS), and outdoor testing facilities (AK, GA, and FSU).

Measurement of Progress and Results

Outputs

• Bioprocessing methods developed in this project using enzymes and plasma treatment will be used to enhance the quality of textile products and have a significant impact on industrial fabric preparation, dyeing and finishing methods.
• Obtaining and characterizing the fiber-forming cellulose or agricultural residues will open doors for fiber producing industries. For example, this work may lead to newer lyocell fiber, which will be better than Tencel<SUP>R</SUP> or a plant source for polyester.
• With an increasing demand for composites and a reduction in petrochemical based polymers, the agriplastics/bioplastics will make a significant impact on the plastics industry and will save the environment by reducing the disposal of non-biodegradable products.
• Plasma treatments will be used to modify the surface of fibers and other products, thus facilitate processing making them more useful. For example, if wheat straw pulp could be made into a spunlaced nonwoven fabric, then it can be plasma-treated to create a surface that would make the fabric an efficient filter for various dye molecules would significantly reduce the extent of environmental pollution.
• Using the database of UV transmission values generated for a variety of fibers and fabrics, a predictive mathematical model will be developed for use by the textile and apparel industry. Publications will be prepared for the medical community to use in advising skin cancer patients, as well as technical publications to share with the scientific community.
• Nonwovens with cotton core will provide not only comfortable nonwovens, but also with PLA on either side will make it biodegradable.
• By identifying and understanding the relationships between specific fabric characteristics and barrier effectiveness, products can be designed and selected for optimum protection. This will provide invaluable info to manufacturers of medical protective equipment and users.
• Publications  cooperative presentations.
• ITAA special sessions
• From Oct. 2001  Sept. 2002, cotton-core degradable nonwovens will be produced. Physical testing and wicking absorbency evaluations of cotton-core nonwovens will be performed at TN, and GA will perform porosity tests. Soil burial tests will be performed at WI. All the participating universities will share results and present their findings at the Multi-state Project Technical Meeting in the fall of 2003. The first papers should be presented at technical conferences such as AATCC, INDA/TAPPI INTC, and TANDEC meetings during 2003-4.
• Refinements will be made in the fabrics as appropriate during 2003-2004, and a second round of performance testing will be conducted during 2003-2005. Additional papers will be presented and published in refereed journals during 2004-2006 and success stories will be featured in newsletters such as TANDEC and University Newsletters (milestone).

Outcomes or Projected Impacts

Milestones

(0):0

Projected Participation

View Appendix E: Participation

Outreach Plan

The results of this regional research project will be made available through presentations at national meeting, refereed and non-refereed publications, special technical publications, annual reports which are published on the projects website, through individual interactions with textile industry representatives, and a comprehensive bulletin that will be published after the projected has been terminated.

Organization/Governance

The project participants will compose the technical committee. For those states having more than one participant, one member will be designated as the voting member, as determined by that institution or AES director. The officers in the committee will consist of a chair, vice-chair, and secretary. The officers along with the project administrative advisor, USDA-CSREES representative, and USDA-ARS administrative advisor will serve as the executive committee. The advisors will be non-voting members.

The general operational procedures will be followed as presented in the CSREES Guidelines for Multi-state Research Activities.

The chair will notify the members of the date and place of the annual meeting, prepare an agenda, preside over the annual meetings, and write the annual report for the year he/she served as chair. The vice-chair will assist the chair with performing the duties of chair and make arrangements for the annual meetings. The secretary will be responsible for correspondence related to the technical committee and for taking/distributing minutes. The technical committee will meet annually to coordinate the research, report and share results, and conduct other activities related to the project. The administrative advisor will authorize all official meetings. Subcommittees and meetings may be designated by the chair, if needed, to accomplish various relevant research and administrative tasks, such as research planning and coordination, the development of specific cooperative research procedures, assimilation and analysis of data from contributing scientists, and publication of regional or other bulletins and reports.

Literature Cited

Attachments

Land Grant Participating States/Institutions

AL, AR, CO, GA, LA, NE, OR, TN, WI

Non Land Grant Participating States/Institutions

Florida State University, Texas Tech University