As Kansas farmer Eric Niemann standsunder a summer sun surveying his fields of soybeans, a warm breezeblows, rippling the sea of green.Scanning the horizon, Niemann sees hismore than 900 acres stretch to meet thesky, and knows he’s not only helpingfeed the world; he’s partnering withresearchers to enhance the future byturning crops into marketable, cost-effective plastics—bioplastics.

“We want to see what we can dowith soybeans in industrial uses,” saidNiemann, United Soybean Board (USB)new uses chairman. “We look aroundand everything is made of plastic.”

Derived from natural resources, bio-plastics hold the hope of eventuallyreplacing petroleum-based counter-parts in the big business of plastics pro-duction. Nearly all of the 90 billionpounds of plastics synthesized eachyear in the United States are made frompetroleum-based polymers (polyethyl-ene, polypropylene, polyvinyl chloride,

p o l y u r e t h a n e ,u n s a t u r a t e dpolyesters, andepoxies).

“The currentinterest in bio-polymers is fueledmainly by envi-ronmental concernsas well as interestin finding newuses for renewableagricultural prod-ucts,” said EugeneStevens, a pro-fessor in theDepartment ofChemistry at StateUniversity of New

York at Binghamton. Stevens has con-ducted biopolymer research for morethan 30 years. “Virtually all plastics aremade from fossil fuels, which are notrenewable, and also there is concern overthe accumulation of waste and pollu-tion,” he said.

The manufacturing of petrochemicalplastics currently uses nearly 300 mil-lion tons of oil and natural gas annu-ally from the world’s supply. Accordingto Stevens, world petroleum suppliesare estimated at around 200 billiontons and are expected to last perhapsonly another 50 years at the presentrate of consumption; natural gas couldrun out about the same time; coal inabout 300 years. But before raw mate-rials run out, production costs will riseto reflect depleting supplies.

Then there’s the problem ofbiodegradability. The qualities thatmake petroleum-based plastics soattractive also make them a burden tothe planetary ecosystem. More than 60billion pounds of plastics find their wayinto the waste stream each year in theUnited States and 35 billion pounds inWestern Europe.

U . S . L E A D S R E S E A R C H E F F O R T S

Although most researchers agree thatEuropean countries are ahead of theUnited States in terms of recycling andenvironmental awareness, the newesttechnology in bioplastics is largelybeing generated by U.S. efforts, saidRichard Wool, professor of chemicalengineering at the University ofDelaware and director of theAffordable Composites from Renew-able Sources (ACRES) program.

“In Europe rapeseed has been lookedat as a lubricant. It could be used tomake composite resins, but no one iscurrently doing that,” Wool said. “Theautomotive industry is probably themost aggressive in terms of coming upwith bio-based components. They’relooking primarily at natural fibers andusing petroleum-based resins.”

In the search to create high-quality,cost-effective bioplastics, researchers haveturned to different raw materials, fromcornstarch, canola, and castor seed oil torapeseed and soy protein. But a plentifulsupply of soybean oil has made it a likelychoice as a renewable plastics feedstock

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Industrial Oils

Bioplastics:A burgeoningindustry

By Lynn Crandall

Spray foam insulation, made fromthe soy-based polyol SoyOyl, pro-vides high performance at a costcomparable to traditional fiberglassbatting. Photo courtesy of UnitedSoybean Board.

for many projects, saidNiemann.

The United Statesproduces about 20billion pounds of soy-bean oil annually,accounting for 80%of seed oils producedin this country.Another 20 billionpounds of soybean oilis produced in SouthAmerica. Through theSoybean Checkoffprogram, which col-lects 0.5% of soybeansales for research andpromotions, the USBhas funded numeroussoy-based research projects and addednew uses for a soy-based polyol.

“The polyol market in the UnitedStates is nearly four billion pounds.Worldwide, we use about nine billionpounds of polyols,” Niemann said.“We started out doing research workwith universities. In the past four tofive years we’ve changed our focus a lit-tle bit to working with industry part-ners to get the products out into themarketplace.”

Carpet with a soy oil-based backingwas recently installed in an office andconference room at a U.S. Departmentof Agriculture (USDA) building as partof a government effort to utilize bio-based products. The carpet backing, athin layer between the fibers and foamcushion that keeps the carpet fibersbound together, was made fromSoyOyl, a soy oil-based polyol manu-factured by Urethane Soy SystemsCompany, Princeton, Illinois, as apetroleum polyol alternative. TomKurth, president of the company, saidthe carpet backing is just one of thenew uses for soybean oil.

“We have an industrial plant that hasthe capacity to produce 325 millionpounds of polyol,” Kurth said. “Withabout 20 billion pounds of polyure-

thane used each year for a variety ofproducts from steering wheels to mat-tresses to shoe cushions to seat or head-rest cushions, our goal is to get 20% ofthe world market in five years. Thattranslates into a new market for 140million bushels of soybeans. And thething is we’re looking at a cost thatruns 10 to 15% less than petroleum-based polyurethane. And it’s renew-able. That’s the really exciting part.”

The market for soy-based polyol sig-nificantly expanded in June when TheDow Chemical Company and Dalton,Georgia-based Universal TextileTechnologies, a major carpet backingsupplier, announced that Biobalancepolymers containing USS’s SoyOyl willbe used in commercial carpet backing.

Wool’s research with ACRES at theUniversity of Delaware is a collaborativeeffort with Kansas State University andnumerous industry partners. The pro-gram has developed a broad range ofchemical routes to utilize natural triglyc-eride oils as the basis for polymers andcomposite materials, incorporating nat-ural fibers, such as flax, chicken feath-ers, and hemp. Although the work hasincluded corn oil, flax oil, and linseedoil, Wool said soybean oil is idealbecause it is a high-quality oil but is

basically a low-cost, sur-plus by-product of thefood industry where thesoy protein usually hasthe higher value. Throughthe ACRES program,Wool has developedapplications in pressure-sensitive adhesives, sheetmolding compounds,wood substitutes, andagricultural and automo-tive equipment, includingside and back panels for a2002 model of a JohnDeere combine in collab-oration with industrialpartners. Wool said thehighest-volume applica-

tion for the plastics has been in the prod-uct used for the John Deere combines,comprised of soy and corn oil resins, butit’s only the tip of the iceberg.

“The agricultural equipment businessis large and that’s where it started, butthe automotive business is larger andthe housing industry is several magni-tudes greater,” he said. “So we’re in theprocess of setting up infrastructure totackle these other high-volume areas.”

A P P L I A N C E A P P L I C A T I O N S

Researchers in the chemistry depart-ment at Iowa State University havebeen developing a soybean oil-basedplastic that could be used as a lining todampen sound and reduce vibration inappliances such as washing machines.The material, created by professorRichard Larock and postdoctoral fel-low Fengkui Li through funding fromthe Iowa Soybean Promotion Board(ISPB), offers a competitive productwith advantages over petro plastics.

“The plastics we get have someunique features that most petroleum-based plastics don’t. . . . And these mate-rials also have shape-memory proper-ties. They will return to their originalshape after being heated, reshaped,cooled, and reheated,” said Larock.

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SoyOyl, a soy-based polyol, is being used in the manufacture of aspray-on truck bed liner sold by Midwest Line-X of Sioux Falls,South Dakota. Photo courtesy of United Soybean Board.

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In April, Minneapolis, Minnesota-based Cargill Dow LLC opened aplant in Blair, Nebraska, that isexpected to use up to 40,000 bushelsof corn per day in production ofNatureWorks PLA (polyactide), aplastic resin derived from cornstarch,and NatureWorks fibers. TheNebraska plant, a joint endeavorbetween Cargill and The DowChemical Co., Midland, Michigan, iscapable of producing 300 millionpounds of NatureWorks PLA annual-ly. Cargill Dow spokesperson MichaelO’Brien said the effort started 12 yearsago with a small research and develop-ment company at Cargill, and repre-sents investments of nearly $750 mil-lion to develop the technology.

“At the time, Cargill was heavilyinvolved in corn wet-milling, or starchprocessing. Based on this business andtheir market research, the group decid-ed to pursue production of PLA,”O’Brien wrote in an e-mail. “Becausewe use corn instead of petroleum, PLArequires 20–50% fewer fossilresources than traditional plastics.”

Production of the product emits 60%fewer green house gases than thoseemitted in production of traditionalplastics, and PLA completely biode-grades in compost facilities, O’Brienwrote. Plans include shipping the prod-uct around the world for use in anarray of consumer applications, includ-ing clothing, food packaging, and bed-ding. The Coca-Cola Co. served drinksin a NatureWorks PLA compostablecup at the 2002 Olympic Winter Gamesin Salt Lake City, Utah. IPER, a leadingsupermarket chain headquartered innorthern Italy, has made commitmentsto convert their fresh food packaging toNatureWorks PLA.

Randy Howard, president and CEOof Cargill Dow, said the appeal of

NatureWorks PLA is based on its over-all performance.

“People buy products based onvalue and performance,” Howardsaid. “What we have done is expandedthe definition of both.”

Howard said the result of the newplant coming on-line will spell a dra-matic increase in the commercial avail-ability of NatureWorks PLA andfibers, as well as pave the way for anumber of consumer products sched-uled for introduction throughout 2002and 2003.

Researchers at the Center for CropsUtilization Research (CCUR) at IowaState University have developed tech-nology for converting soy protein intoa bioplastic compatible with numerousindustrial techniques including extru-sion, compression molding, and injec-tion molding.

“We add biodegradable polymersto the soy material. We add plasticiz-ers to help in the processibility, andcompatibilizers to help mix the twocomponents,” said Jay-Lin Jane a pro-fessor in the department of FoodScience and Human Nutrition whodeveloped the new compound withresearch scientist Perminus Mungara.“Basically we mix all the ingredientstogether and then it would be extrud-ed and chopped into pellets. The mate-rial is then used for making differentproducts.”

Soy Works Corp., a development-stage company based in Woodridge,Illinois, acquired worldwide exclusivecommercial rights for the researchers’patented technology in 1998. RoyTaylor, president and CEO ofSoyWorks, said the company has for-mal and informal agreements withcompanies interested in the materialsand expects to introduce an array ofproducts by 2003.

“We’re working on building mate-rials, meat trays, burger clam shellsand take-out food containers, cutlery,golf tees, packaging and packagingcomponents, stretch wraps andmulching films. There’s a long list ofthings we feel really good about,” hesaid. “Products can be manufacturedusing equipment standard to the plas-tics industry and at very competitivecosts.”

Jane said her biodegradable materi-als offer 50% biodegradability within10 to 14 days in soil or water environ-ments. Additionally, studies haveshown growth enhancement whenarticles formed from the material areground up and applied to crops.

Procter & Gamble Co., Cincinnati,Ohio, has taken steps to commercializeits family of bio-based, biodegradablealiphatic polyesters (polyhydroxyalka-noates: PHA), called Nodax™. To pro-duce the materials, a variety ofmicroorganisms will be used, saidNorma McDonald, associate directorof External Business Development andGlobal Licensing, and the company’sresearchers are still exploring both ani-mal- and vegetable-based substrates ascarbon sources. Nodax™ polymers areadaptable to a wide range of applica-tions, including fibers/nonwovens,foams, synthetic papers, films, extru-sion coatings, adhesives, latex, andinjection- and blow- molded articles.

According to McDonald, the familystarts with short-chain materialswhere the first co-monomer is C4(polyhydroxybutyrate). The sidechains provide varying degrees ofbranching and vary in length from C6(polyhydroxyhexanoate) to C24.

Kaneka Co., Osaka, Japan, is thefirst licensed producer of C4C6 and isexpected to gain large-scale commer-cialization within two to three years.

Technology for bioplastics production isn’t confined to oil- and fat-based resources

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The soy bioplastics are prepared bythe cationic polymerization andcopolymerization of regular, LoSat, andconjugated soybean oils (30–65 weightpercent) with commercial co-monomers, including styrene anddivinylbenzene. The plastics possesspetro plastic characteristics with roomtemperature moduli ranging from 6 χ 106 to 2 χ 109 Pa and glass-transi-tion temperatures ranging from 0 to105ºC. The maximum tensile strengthof the materials reaches as high as 21MPa. The thermal stabilities range

from 340 to 400ºC for 15% weight lossvalues in air.

Although the material offers a com-petitive price advantage, the researchersare continuing to explore other possiblecross-linking agents that would becheaper and more environmentallyfriendly, Larock said. They’re alsoexpanding the work to include compos-ites with agricultural fibers and arelooking for industrial partners to helpdevelop their patented plastic.Currently, the Center for AdvancedTechnology Development and Iowa-based Sheaffer Pen, Souvenir/Norwood, Jebro Inc., HeartlandResource Technologies, CreativeComposites, and Municipal Pipe Toolare working to explore commercialpossibilities.

Larock said that although soybeanoil’s abundance and cost-effectivenessstrengthen its advantage as a bioplasticfeedstock, his work has included abasic survey of corn, fish, tung, peanut,sunflower, walnut, and other naturaloils with results consistent with soy-bean oil.

U S D A R E G I O N A L R E S E A R C H

C E N T E R S ’ R E S E A R C H

Soy oil-based bioplasticresearch at the NationalCenter for AgriculturalUtilization Research(NCAUR) in Peoria,Illinois, is finding a vari-ety of applications.

Randal Shogren, researchchemist in the plant poly-mer division at the cen-ter, is field-testing agri-cultural film at theUniversity of Florida,Cornell University, andMead Westvaco, a papercompany that growstrees. The film, kraftpaper coated with poly-merized soybean oil, hasdemonstrated advantages

over polyethylene mulch in ease of useand biodegradability.

“There’s a lot of polyethylene filmused in agriculture to keep weeds out,heat up the soil, and retain moisture.On the order of 300 million pounds ayear are used in the United States and 1billion pounds worldwide,” Shogrensaid. “The problem is in the disposal.It’s difficult to remove from the field andexpensive. Then, once it’s removed, youeither have to landfill it, which manylandfills won’t accept, or burn it, whichis illegal in many places. The biodegrad-able mulch can be simply tilled into thesoil at the end of the season.”

Although the up-front cost of thebio-based mulch currently is higherthan its petroleum counterpart,Shogren said it is comparably pricedwhen the cost for removal and disposalof polyethylene is factored in.

Beyond its biodegradability and easeof use, Shogren’s product has demon-strated numerous benefits pleasing tofarmers. The kraft paper/soy oil mulchresists penetration by certain weedscapable of penetrating plastic mulch,thus reducing the need for applicationof methyl bromide (a chemical currentlyraising concerns over its contribution

Volume 13 • August 2002 • inform

Joseph Jen, USDA undersecretary forresearch, education, and economics,shows off carpet backed with a soy-based material that was recentlyinstalled in some of the USDA’soffices in Washington, DC. Photocourtesy of United Soybean Board.

Scientist Randal Shogren installs agricultural filmin a field to prepare for a test of the product hedeveloped. Photo courtesy of NCAUR.

to ozone depletion). The paper mulchcan be made water-permeable, anadvantage to farmers who do not irri-gate with drip lines under plastic mulch.Shogren’s mulch also enhances thepotential for a cleaner crop for tree andcotton farmers, who often find theirharvest contaminated with black plasticflecks from the polyethylene mulch.

Sevim Erhan, research leader in theFood and Industrial Oil Research divi-sion at the center, and postdoctoralresearch associate Zengshe (Kevin) Liuhave applied for a patent for their bio-plastic application of solid free-formfabrication (SSF), a system that usesepoxidized soybean oil-based polymerslurries for use in fabricating objectswithout the need of a mold.

The system utilizes a motorizedsyringe mounted on an x–y drive. Acomputer program instructs the syringeto “write” a thin stream of slurry, madeof soybean oil, fiber, and gelling agent,much like a three-dimensional pen plot-ter. Moving over a support surface, thesyringe traces out the first layer of theobject, then moves up successive steps,writing additional layers to form asolid object. The object is then heat-cured.

The researchers have found the tech-nique cost-effective and easily adaptablefor different end-use applications. Thebioplastic product exhibits durabilityequal to petroleum-based plastics andcan be altered by using different carbon,glass, mineral, or natural fibers.Although the material is capable ofworking with current mold technology,the ability to create any object without amold affords greater flexibility, Liu said.

“We can make any shape by tellingthe computer to do it, and there is noproblem with releasing the object fromthe mold or with having seams,” he said.

Erhan said the process would be par-ticularly useful for making parts that aredetailed or one-of-a-kind. The techniqueis attracting a lot of attention from com-panies with a variety of interests.

A research team led by DanielSolaiman, a lead scientist in the Fats,Oils, and Animal Coproducts ResearchUnit of the Eastern Regional ResearchCenter, Agricultural Research Service,USDA in Wyndmoor, Pennsylvania, isdeveloping a fermentation-basedbiotechnology process to convert ani-mal fats, plant oils, and their co-prod-ucts, as well as waste streams into,among other things, poly(hydroxyalkan-oates) (PHA). [PHA were discussed byVanessa Bongcam and Yves Poirer ofthe University of Lausanne,Switzerland, in the August 1999 issueof inform (10:768–774).] A biodegrad-able polyester, PHA is synthesized andsequestered in intracellular granules bymicroorganisms and extracted with sol-vent. The biopolymers created in thisprocess can have properties rangingfrom those of thermoplastics and elas-tomers to adhesives, depending on themakeup of the polymers.

“In nature, there are many bacteriathat will produce plastics. But not all ofthem can use fats and oils directly. Sowhat we do is select strains that canproduce plastics, use genetic modifica-tion to make them able to use fats andoils, and vice versa,” Solaiman said.“Furthermore, by selectively feedingthe bacteria with, for example, soybeanoil, we can produce one kind of plastic.If we feed them another oil, we get

other types of characteristics. So byselective feeding we can manipulate ortailor the characteristics of the biopoly-mers.”

Solaiman said an advantage of histeam’s process over other methods isthat it can utilize not only renewableagricultural oil but also by-productsand waste streams of oil and fat pro-cessing and recycled materials. By usingrenewable and recycled materials asfeedstocks, the process is ecologicallyadvantageous and helps contain thecost of the bioplastic.

Although PHA are not currentlywidely used in commercial applica-tions, Solaiman said there is animmense potential for the product in ahost of applications, such as adhesives,coatings, fibers, films, and tissue engi-neering. He and his group continue tomanipulate the PHA-forming processwhile also investigating the fermenta-tion of the same feedstocks to surfac-tants using yeasts.

T H E F U T U R E

While many consider the technology ofbioplastics an emerging field, it is actu-ally a resurgence, Stevens said. He notedthat many natural polymers were com-mercialized in the 19th century in prod-ucts such as animal horn snuffboxes, bil-liard balls, hairpins, and buttons. Themost widely used commercialized prod-uct was celluloid, used in motion picturefilms, combs, and other decorative items.And in 1941, Henry Ford made proto-type automobile parts out of soy meal.But the technology was primitive andwas set aside when World War II divert-ed industrial interest to defense efforts.

While petroleum-based plastics con-tinue to dominate the market,prospects of bioplastics taking a sub-stantial share will ultimately depend onconsumer acceptance and governmentencouragement, Stevens said.

Lynn Crandall is a freelance writerbased in Ludlow, Illinois.

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A research team led by DanielSolaiman is developing a fermentation-based biotechnology process to makePHA. Photo courtesy of ERRC.