There may be a market for more than 265 million tires discarded yearly. ARS researchers have found a new way to recycle material from used tires. They extract the pulverized rubber and polyester/nylon mixture and divide it into two separate materials. The polyester/nylon fiber is called fluff, and the rubber material is called crumb. Rubber and polyester/nylon fibers are then pulverized using either a freezing treatment and a hammer mill, or by grinding up the material. More than 50 percent of the rubber from this process is recovered, and the remainder is sent to landfills. The recovered rubber is valued at about $500 per ton. A company that places 12 tons per day in a landfill could potentially turn that into an additional $5,700 a day. This process is based on cotton ginning technology. Products such as new tires, truckbed liners, running tracks, shoes, carpet backing, brake pads and shoes, asphalt, water hoses and floor mats can be made from the recycled rubber. Several companies are considering licensing this technology. (PATENT APPLICATION 09/107,760)

Cotton Ginning Research, Stoneville, MS
W. Stanley Anthony, (601) 686-3094, anthonys@ars.usda.gov

When the oil embargo of the 1970's hit, America's farm tractors continued to roll regardless of the oil shortage thanks to ARS research that turned vegetable oils into alternative fuels. The trend will continue in the 21st century, when motorists will see more vehicles--buses, trains, trucks, and government-owned maintenance equipment--running on biodiesel fuels made from soybean oil. To help speed the development of biodiesel fuels made with vegetable oils, ARS scientists in Peoria, IL, have adapted a sophisticated tool known as near-infrared spectroscopy, or NIR. NIR is an easier and faster way to check the quality of biodiesel fuel than using gas chromatography, or GC, the current standard analytical tool for measuring biodiesel quality. GC requires more technical expertise and at least an hour to perform. Another drawback: GC requires special chemical reagents and solvents that need special handling and costly disposal. Using NIR, researchers can measure the conversion of vegetable oil to biodiesel fuel in less than a minute. NIR, coupled with a fiber-optic probe, uses light rather than chemicals to perform the analysis. The new test will help biodiesel fuel producers determine if their products meet the quality standards of the American Society for Testing and Materials.

National Center for Agricultural Utilization Research, Peoria, IL
Gerhard H. Knothe, (309) 681-6417, knothegh@mail.ncaur.usda.gov

A textile treatment that improves thermal adaptability, absorbency and other desired functional properties in fabric may offer another important benefit. Coating the fabric with polymers called polyethylene glycols (PEG’s) can reduce the growth of certain fungi and bacteria by almost 100 percent, ARS and University of Georgia researchers report. It works by creating an unfavorable environment for the microbes on and around the fibers of cotton, polyester and other fabrics used to make clothing, linens and other textile products. Researchers observed substantial growth reductions after inoculating PEG-treated swaths of cotton- polyester bed sheets with spores of two bacteria, Stapholoccus epidermidis and Brevibacterium epidermidids, and two fungi, Aspergillus fumigatus and Microsporum cookel. Staph bacteria can cause skin, wound and other infections. Brevibacterium causes foot odor. Both of the fungi can trigger allergies and asthma. Besides creating an unfavorable growth environment, the PEG fabric treatments may also dehydrate the microbes, rupturing their cell membranes More research is needed to confirm the finding. But early indications are the treatment could give clothing and textile makers a new way to incorporate antimicrobial properties into apparel or health care products like underpads used by people with incontinence. Another benefit: scientists believe the PEGs’ antimicrobial action is more physical than chemical. So, fabric-infecting germs should be less apt to develop resistance.

Southern Regional Research Center, New Orleans, LA
Tyrone Vigo (504) 286-4487, tvigo@commserver.srrc.usda.gov

Liquid epoxies made from cane sugar may help open a new industrial outlet for the sweetener in the form of adhesives, primers, base coats and composite materials. More than 3 million tons of U.S. cane sugar is produced annually but less than 2 percent is used for nonfood purposes. Cane sugar also has to compete with artificial and low-calorie sweeteners. Unlike these products, however, it offers an abundant, chemically pure source of raw material for creating liquid epoxies that bind glass, metal, wood and other materials. That’s the implication of studies by ARS and university scientists who created the sucrose epoxies. In one experiment, for example, it took more than 1,000 pounds of force to separate two aluminum plates coated with a hardened sucrose epoxy. The material dries under many different temperatures, forming either a clear glass or rubbery material. And, unlike today’s petroleum-based epoxies, the sucrose material doesn’t contain starter ingredients like Bisphenol-A. Some research suggests this chemical may disrupt the reproductive systems of mice, and possibly humans. If the sucrose epoxies are to offer a nontoxic alternative, they’ll have to challenge the petroleum products in such areas as price, performance and marketability. ARS scientists hope to explore such prospects under a cooperative agreement with an industrial partner.

Southern Regional Research Center, New Orleans, LA
Navzer Sachinvala, (504) 286-4324, nozar@commserver.srrc.usda.gov

Guayule, a native shrub that yields high-quality, hypoallergenic natural latex, is now easier to genetically engineer. A technique refined by ARS scientists should simplify the job of giving tomorrow's guayule new genes that could boost its production of latex, or enhance resistance to a root rot that can attack this otherwise disease-resistant plant. Guayule (pronounced why-YOU-lee) yields a milky latex which is free of allergens that can cause severe reactions such as anaphylactic shock. An estimated 20 million Americans may be allergic to natural latex in gloves, condoms or other products made from the most widely used source, the Brazilian rubber tree. ARS scientists bathed pieces of guayule leaves in a solution containing a reworked form of a microbe, Agrobacterium tumefaciens. The microbe, with the experimental genes inside, can slip genes into guayule cells. The leaf pieces are then nurtured to form plantlets. The approach is based on a procedure already widely used to genetically engineer other plants, but the ARS team is apparently the first to use it successfully with guayule. Their approach could replace an earlier, cumbersome technique that required piercing plants with a very thin needle to make an entryway for the microbe. Native to Texas, guayule has been grown experimentally there as well as in California, Arizona and New Mexico.

Western Regional Research Center, Albany, CA
Katrina Cornish, (510) 559-5950, kcornish@pw.usda.gov