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Inventions waiting in the wings.

"Build a better mousetrap," the saying goes, "and the world will beat a path to your door."

But it seems that sometimes those clamoring crowds get lost on the way to the inventor's doorstep. The invention is ready, the inventor is eager for interest--and the days tick by uneventfully.

The path to the doorsteps of inventors with the Agricultural Research Service has been smoothed considerably by the Federal Technology Transfer Act of 1986.

This act encourages companies to work with ARS scientists under a formal Cooperative Research and Development Agreement. In return, these cooperating companies get the first chance at exclusive licenses to use the technology that emerges from the joint effort. The Agricultural Research Service has obtained more than 1,200 patents to date, and 411 licenses have been granted to companies or universities. But there are plenty of inventions still waiting on the shelves; what follows are a few of the more intriguing "might-have-beens" that still have development potential.

Bouncing Bushels

In the classic silent film "The Gold Rush," a starving Charlie Chaplin makes a hilarious meal of his shoe, fight down to the shoelaces. And William M. Doane knows a way the mbber sole might at least have been tastier, if not more nutntious.

Doane, who works in the Plant Polymer Research Unit at the National Center for Agricultural Utilization Research (NCAUR) in Peoria, Illinois, says that starches from plants such as corn can make up as much as 30 percent of rubber products, be they shoe parts, kitchenware, or automobile tires.

Of course, Doane doesn't expect a big demand for edible shoes. But he says switching to starches as rubber reinforcing agents could significantly reduce reliance on a prime ingredient with a petroleum base: carbon black.

"Manufacturers start with a big chunk of material called elastomer, and they add as many as 40 ingredients to make it become the rubber we know," he says. "Up to 30 percent of a tire may be reinforcing agents."

Carbon black is a major player among those reinforcing agents, with a 3-billion-pound annual market that practically begged the attention of ARS researchers, Doane says.

"We started finding ways to make a starch derivative we could put fight into the latex," he recalls. "One advantage would be that without the carbon black, you'd have "white" rubber that could be colored any way you wanted."

The Peoria researchers actually hit the development jackpot twice: with reinforced rubber containing up to 30 percent starch and with a powdered rubber process that uses 3 to 5 percent starch and cuts the time it takes to go from raw rubber to molded product by 90 percent.

The type of starch can vary, Doane says, "but we found cornstarch is generally less expensive. As far as performance, though, there's not much difference among starches from com, wheat, or grain sorghum."

Both reinforced and powdered rubber formulations were patented in the late 1960's. "But we couldn't give an exclusive license in those days, so firms weren't interested," Doane says.

"There's certainly still a market. You can get 30 pounds of starch per bushel of corn, so something that uses 3 billion pounds of starch would mean a market for an extra 100 million bushels of corn."

Grow Your Own Plastic

A crop called crambe is growing on some 20,000 acres in the United States this year. But if you want to see what comes from crambe, don't watch your local produce section-check out the plastic goods instead.

Crambe is touted as a domestic source of erucic acid, which now comes into the United States mainly in the form of rapeseed oil from Canada and Europe.

When erucic acid is treated with ammonia, it forms amides, an excellent material for preventing various types of plastic sheets or films from sticking together as they're manufactured and used. Amides constitute a profitable market for erucic acid, but as the United States boosts its crambe production, other outlets will be needed as well.

Enter Nylon 1313, so called because the erncic acid molecule is split and treated to form the nylon's 13-carbon polymer chains.

"Nylons are all very solvent resistant, tough, and strong," notes Kenneth D. Carlson who works in the NCAUR's Oil Chemical Unit and the New Crops Research Unit. "But Nylon 1313 is special because it absorbs the least amount of moisture of any commercial nylon made so far." This means Nylon 1313 can be molded into items such as automobile parts, gears, and tubing that must not swell or shrink in humid settings. Nylon 13 l 3 absorbs only about 0.7 percent moisture; by comparison, its cousin, Nylon 11, used in parts for autos and trucks, absorbs about 1.5 percent.

Nylon 1313 stirred some interest, but commercialization was hindered by the expense of the process for splitting the erucic acid molecule. Now new processes developed at North Dakota State University with state and USDA funding may cut that cost in half, Carlson says.

"Nylon 1313 has also been held back by low supplies of erucic acid, which hasn't been available at sufficiently low cost," he adds. "But if crambe production moves along as it is now, that cost could come down."

Cleaning Up Naturally

Detergents may sound like a dirty word to environmentalists, but Warner M. Linfield knows of one detergent that could be good for your clothes, the environment, and the economy: soap.

The problem is, ordinary soap doesn't wash well in water that's cold or hard--loaded with calcium or magnesium. When soap meets hard water, a curdlike substance called lime soap forms--the culprit behind bathtub ting. And there's more bad news: When you use soap to wash laundry in hard water, your clothes come out feeling greasy.

The solution is to add a surfactant--a material in the soap that lowers surface tension so water can penetrate better. At the Eastern Regional Research Center (ERRC) at Philadelphia, Pennsylvania, where Linfield was a research leader until his retirement in 1984, the surfactant of choice came from a natural product: tallow.

"Tallow is mostly beef fat from meat packing houses and food processing companies," says Linfield. "We wanted to find a way to use it."

Linfield and coworkers blended soap with tallow-based surfactants called lime-soap dispersants. The principle of soap plus surfactants is not a new one, but it has never been used commercially for laundry cleaning.

Linfield's resultant tallow-laced soap is very environmentally friendly. The soaps contain no phosphates; won't harm humans, livestock and domestic animals, or wildlife; and will usually biodegrade within 24 hours. "Bacteria in the sewers and soil eat them up," says Linfield.

While some U.S. toiletry manufacturers use old-fashioned soap with limesoap dispersants, Linfield says it's not used in the United States as a laundry cleaner. But that's not because it won't do the job.

"We conducted our own tests, and a large soap company also ran tests," he recalls. "We used cloth artificially soiled with fat and lamp black and measured the grayness left after laundering.

"Our soap took out as much as the leading laundry products. The soap company got the same results on laundry bundles. They told us if they'd known about this in the 1950's, they wouldn't have gone to petrochemical-based detergents."

A major reason for the detergent industry's reluctance to change is the expense of scrapping current equipment and switching to soap-making gear.

"That wouldn't be anything small," Linfield admits. "But these soaps would be good for the environment and economical, too."

All-American Chocolate

Tallow could also constitute a good substitute for imported cocoa butter, one of the world's most expensive food fats. At ERRC, scientists in the 1970's actually produced chocolate bars made from edible tallow. [See also "Cocoa Butter from Cottonseed Oil," Agricultural Research, June 1992, p. 18.]

"The thing that's special about cocoa butter is its physical characteristics," notes chemist James W. Hampson, who worked on the project.

"It's a solid at room temperature, but it melts at body temperature. It completely melts in your mouth, and there's no waxy taste. Also, it comes out of a mold easily."

But cocoa butter probably doesn't seem so sweet to budget-watchers at candy companies: The United States last year imported about 205 million pounds of the fat, with a customs value of more than $279 million.

As a substitute, edible tallow is hardly in short supply; U.S. production for the marketing year that began October 1, 1991, is expected to hit 1.35 billion pounds.

The Philadelphia researchers knew the composition of certain fat molecules called triglycerides were similar in tallow and cocoa butter, so they began studying the tallow triglycerides' other qualifies, such as melting characteristics.

"There were more similarities than differences," Hampson recalls.

Limiting factors proved to be the relatively complex process used to extract the tallow triglycerides and questions about whether a tallow chocolate bar could be labeled kosher. The scientists' process was ultimately patented and several companies obtained licenses, but Hampson says interest has since waned.

"We were shooting for a cocoa butter equivalent, not just a substitute," he says. "I think we came pretty close."

Putting Fat To Work

Imagine being able to take off fat as though it were a raincoat. It could come true--if the plastic in the raincoat were made from fat.

That's no pipe dream, says microbiologist Rodney J. Bothast. He says all kinds of plastics--even for clothing-- can be made from fats, especially vegetable fats such as those found in soybean oil.

"Back in 1978 when we were so concerned about using renewable resources for fuel we became once again interested in using vegetable oils for diesel fuel," recalls Bothast.

"The backbone of fat is glycerol with three fatty acids attached. When fuel is made, the fatty acids are used in the fuel, and the glycerol is left over."

Researchers at the NCAUR fermented the leftover glycerol using a bacterium called Klebsiella pneumoniae to produce a material called 3-HPA (3hydroxy-propionaldehyde).

Heating 3-HPA turns it into acrolein. When a single oxygen molecule is added to acrolein, the result is acrylic acid, which can be used to make plastic goods, "everything from artificial fingernails to car bumpers," says Bothast.

Acrylic acid is now made from petroleum, and it takes 3 pounds of petroleum to produce a single pound of acrylic acid.

"In our process, you can use corn, vegetable fat, or any other kind of fermentable material," says Bothast. "We can even use animal fat."

Consumers probably won't see plastics from fats until the alternative fuels industry picks up steam, Bothast says, because that's likely to be the best source of abundant glycerol.

"If a cheap glycerol source exists, this could be done," he says.

One-Step Yarn

Making a simple cotton yam can be anything but simple. Just ask research physicist Devron Thibodeaux.

"It typically takes five different machines to make spun yam from a tuft of cotton," says Thibodeaux, a researcher in the Southern Regional Research Center's Fiber Physics and Biochemistry Research Unit at New Orleans, Louisiana. "Each of those machines makes its own product that must be carried to the next machine."

ARS researchers at New Orleans had a better idea: a single machine that can take in the raw cotton at one end and spit out yarn at the other, cutting down on floor space, energy needs, and, best of all, costs.

The machine has three stages of production--fiber preparation, fiber distribution, and yam formation. Vanous components of the machine have been patented and are being used by the textile industry, although no one has yet put the overall package to work, says Thibodeaux.

In one economic study, floor space for a conventional open-end spinning system was calculated at about 66,378 square feet, compared with only 15,744 square feet for the tuft-to-yam system.

The same study estimated manufacturing costs using open-end spinning at about 22 cents per pound of spun yam, compared with about 18 cents using the tuff-to-yam system.

"One reason this was not picked up by industry is that back in the 1970's when we did the work, we couldn't grant an exclusive license to a company, so no one in industry wanted to get involved," says Thibodeaux.

"We built one of these machines, and we showed that it will work for a wide range of commercial yam sizes," he adds. "But for now, it looks like the textile industry is satisfied with the equipment it already has."

Drugs From Nature

You don't have to go all the way to the South American rain forest to find cancer-fighting dmgs. The weedy field across the way may serve just as well, if it's loaded with certain members of the sesbania family.

Sesbania drummondii, S. punicea, and S. vesicaria all contain a substance called sesbanimide that has demonstrated anti-tumor activity in mice with leukemia, according to ARS chemist Richard G. Powell, who is in NCAUR's Bioactive Constituents Research Unit.

Livestock producers have long been wary of these weeds, commonly known by such names as rattlebrush, rattlebox, coffeebean, bagpod, and bladderpod, because grazing animals as well as chickens and hogs can succumb to the powerful toxins in the seeds.

But when extracts from S. vesicaria were sent to the National Cancer Institute in the 1960's for testing as part of a random sampling of various plants, scientists began looking at sesbanias in a whole new light.

In NCI tests, mice that received only 0.01 milligrams of sesbanimide per kilogram of body weight survived leukemia 1.71 times longer than mice that received none of the toxin.

But sesbanimide isn't without problems. For starters, it's hard to come by: 1,000 pounds of sesbania yields only about 2.5 grams of sesbanimide.

Also, "The line between the effective dose and the toxic dose is very fine," he adds. "With drug treatments for cancer, that's always a problem, because the treatments are often toxic to all cells, not just the cancerous ones."

Furthermore, Powell emphasizes, lengthy and expensive clinical tests would be required before these results could be applied to humans.

At least one major pharmaceutical firm has studied sesbanimide and has been stymied by its obstacles. To date, sesbanimide remains a tantalizing puzzle.

"The hope is to find cancer drugs that are specific for certain tumor cells, not just generally toxic," Powell concludes. "Sesbanimide is generally toxic, although it has shown some specificity for leukemic cells in mice."

Horace G. Cutler is another ARS scientist who sees solutions to people's problems in nature. Leader of the Microbial Products Research Unit at Athens, Georgia, Cutler focuses on microorganisms as weapons.

"One of our first compounds was isolated in 1977-78 from old unbleached flour," he recalls. "It was called hydroxyterphenyllin and it turned out to have rather interesting plant growth regulatory effects."

In other studies, Cutler has found a compound from a mold growing on pine logs that's effective against Aspergillus flavus, the fungus that produces aflatoxin in peanuts and grain. Also, he's recovered a compound from rotten pecans that fights late blight of potato, the crop disease that prompted the great migrations from Ireland in the 1800' s.

"Nature is highly ingenious," he says. "You have to consider all the possibilities. We've discovered a lot of natural compounds with which to safely protect our food supply."--By Sandy Miller Hays, ARS.

For information about these ARS inventions, contact M. Ann Whitehead, Patent Coordinalor, USDA, ARS, OCI, Room. 403, Bldg. 005, BARC-West, Beltsville, MD 20705. Phone (301) 5046786, fax number (301) 504-5060.
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Author:Hays, Sandy Miller
Publication:Agricultural Research
Date:Sep 1, 1992
Words:2579
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