Bio-resins tackle durable applications.Bioplastics were initially created for single-use applications like packaging and hotel key and gift cards. Their key benefit was that they wouldn't stick around long in the environment because of their degradability de·grad·a·ble adj. That can be chemically degraded: degradable plastic wastes. de·grad and compostability. But now, compounders of bio-resins are beefing up their properties for durable applications. New grades target automotive, electronic, and construction parts. To overcome most biopolymers' inherent brittleness, low heat resistance, and processability limitations, they are being alloyed with conventional resins and fortified fortified (fôrt  ´fīd),adj containing additives more potent than the principal ingredient. with impact modifiers, reinforcing fillers, and nano-additives (see Learn More box). [ILLUSTRATION OMITTED] In 2007, the European Bioplastics Association in Berlin, predicted that durable applications would grow from 12% of global bioplastics usage that year to 40% by 2011, despite there being almost no durable biopolymers on the market a year ago. The attraction of durable biopolymers is "renewable carbon" in place of "fossil carbon" and possibly reduced energy consumption and CO2 greenhouse-gas emission in their production (though that is hard to measure). Another big motivation (and the reason many of the new engineered biopolymers are coming from Asia) is to meet a Japanese government directive that 20% of all plastics used in Japan must be bio-derived by 2020. This directive opened the way for partly bio-based resins--alloys or blends of bio- and petrochemical materials, which both reduce the overall "carbon footprint A carbon footprint is the total amount of carbon dioxide (CO2) and other greenhouse gases emitted over the full life cycle of a product or service. " and improve the biomaterial's properties. The new durable biomaterials discussed here include ones based on polylactic acid polylactic acid /poly·lac·tic ac·id/ (-lak´tik) a hydrophobic hydroxy acid polymer that is formed into granules and used as a surgical dressing for dental extraction sites. (PLA (Programmable Logic Array) A type of programmable logic chip (PLD) that contained arrays of programmable AND and OR gates. PLAs are no longer used. See PLD. (language, music) Pla - A high-level music programming language, written in SAIL. ), polyhydroxy alkanoates (PHAs) such as PHBV, and industrial starch. Some of the first engineered materials made with these biopolymers are now commercially available, and adventurous processors are trying them out. There are, of course, also established engineering resins that have recently adopted the "bio" label, such as nylon 610 and 11, which are based on castor oil castor oil, yellowish oil obtained from the seed of the castor bean. The oil content of the seeds varies from about 20% to 50%. After the hulls are removed the seeds are cold-pressed. . And a growing number of existing resins for durable goods--PEBA and copolyester TPEs, TPUs, and even PMMA PMMA polymethyl methacrylate. (acrylic)--are being made with some renewable content (see Learn More). But already established materials are not the focus of this article. ALLOYING, MODIFYING Most durable bio-resins marketed today are based on PLA, of which supplies are currently tight, so amounts of the new alloys are still limited. PLA is being blended with petrochemical-based PC, PP, ABS, HIPS, PET, and PMMA--plus fillers, fibers, and additives to inhibit degradability, increase HDT HDT Heat Deflection Temperature (plastics) HDT High Dose Therapy HDT Heatpipe Direct Touch (Xigmatek) HDT Heat Distortion Temperature (plastics) HDT Henry David Thoreau , reduce brittleness, and speed crystallization Crystallization The formation of a solid from a solution, melt, vapor, or a different solid phase. Crystallization from solution is an important industrial operation because of the large number of materials marketed as crystalline particles. . Blending with ABS, for example, reduces brittleness. ABS mixes easily with PLA, making a two-phase blend that is opaque. Blending PLA with polyethylene or copolyesters also reduces brittleness. Mixtures with polyolefins are opaque, but blends with PMMA are clear. PLA is also blended with other bioresins like PHBV (polyhydroxybutyrate valerate) or other PHAs, which have properties similar to low-end ABS and can reduce brittleness. PHBV also improves PLA's heat resistance, but the mix loses clarity and is reportedly harder to process. PHBV is available in pilot quantities from Tianan Biologic Material Co. in China. A commercial plant (22 million lb/yr) will open in early 2010. Another PHA PHA abbr. phytohemagglutinin PHA phytohemagglutinin, a plant lectin. , tradenamed Mirel, is available in developmental quantities from Telles in Lowell, Mass., a joint venture of Archer Daniels Midland The Archer Daniels Midland Company (NYSE: ADM), is a conglomeration based in Decatur, Illinois. ADMoperates more than 270 plants worldwide, where cereal grains and oilseeds are processed into numerous products used in food, beverage, nutraceutical, industrial and animal feed and Metabolix. The first commercial plant for Mirel (110 million lb/yr) is expected to start production in the second quarter. Additives also play a role in beefing up bio-resins for durable uses. Talc talc, mineral ranging in color from white through various shades of gray and green to the red and brown of impure specimens, translucent to opaque, and having a greasy, soapy feel. as a nucleating agent speeds PLA's crystallization and reduces molding time somewhat. Calcium sulfate Noun 1. calcium sulfate - a white salt (CaSO4) calcium sulphate gypsum - a common white or colorless mineral (hydrated calcium sulphate) used to make cements and plasters (especially plaster of Paris) (dehydrated de·hy·drate v. de·hy·drat·ed, de·hy·drat·ing, de·hy·drates v.tr. 1. To remove water from; make anhydrous. 2. To preserve by removing water from (vegetables, for example). gypsum gypsum (jĭp`səm), mineral composed of calcium sulfate (calcium, sulfur, and oxygen) with two molecules of water, CaSO4·2H2O. It is the most common sulfate mineral, occurring in many places in a variety of forms. ) improves heat resistance. Very fine-particle (0.05-micron) silica increases toughness while maintaining clarity. Reinforcing PLA with a network of polymer-crosslinked carbon fibers adds thermal conductivity for use in electronic applications. A special high-aspect-ratio precipitated calcium carbonate calcium carbonate, CaCO3, white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. from Specialty Minerals, called EMforce Bio, is also said to reduce PLA's brittleness. A 30% loading of EMforce Bio in PLA reportedly achieves dart impact strength of 35 ft-lb, vs. 3 ft-lb for unmodified Adj. 1. unmodified - not changed in form or character unqualified - not limited or restricted; "an unqualified denial" modified - changed in form or character; "their modified stand made the issue more acceptable"; "the performance of the modified aircraft PLA, and shows ductile ductile /duc·tile/ (duk´til) susceptible of being drawn out without breaking. duc·tile adj. Easily molded or shaped. ductile susceptible of being drawn out without breaking. failure. Not everyone thinks PLA should be made durable. Biopolymer bi·o·pol·y·mer n. A macromolecule, such as a protein or nucleic acid, that is formed in a living organism. biopolymer any protein or nucleic acid produced by a living organism. compounder Cereplast uses PLA only for degradable de·grad·a·ble adj. That can be chemically degraded: degradable plastic wastes. de·grad compounds and prefers industrial starch for its durable bio-compounds. "PLA with its beautiful clarity and degradability shouldn't be used for opaque durable applications, but for compostables," says Cereplast president Frederic Scheer. "And the market for durables is in the billions of pounds. There simply isn't going to be enough PLA to meet durable demands for decades ahead." Commercial supplies of PLA are growing to meet at least near-term needs. NatureWorks, the sole large-scale supplier, has debottlenecked its plant in Blair, Neb., from 150 million lb/yr to 300 million lb capacity this year. Hisun in China makes 11 million lb/yr, and a couple of new semi-works PLA plants have been announced in Europe, but construction has not yet begun. [ILLUSTRATION OMITTED] MAKING PLA TO LAST Durable PLA-based resins appeared as long ago as 2003, when Toray Industries Toray Industries, Inc. (東レ株式会社 Tōre Kabushiki-gaisha in Japan commercialized its Eco-Plastic PLA compounds with chemically coupled kenaf Noun 1. kenaf - fiber from an East Indian plant Hibiscus cannabinus deccan hemp bimli, bimli hemp, Bombay hemp, Hibiscus cannabinus, kanaf, kenaf, Indian hemp, deccan hemp - valuable fiber plant of East Indies now widespread in cultivation fiber for a spare-tire cover on the Toyota Raum The Toyota Raum is a small, five-seat minivan that first appeared in May 1997. The second generation was released in May 2003. It is sold only in Japan.
Toray has since commercialized a laptop computer cover for Fujitsu, using a 50/50 PLA/PC blend and flame-retardant additives. The 50/50 blend reportedly has the processability, heat resistance, and flame resistance required for larger IT devices, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. a NatureWorks white paper. But with less than 50% PC, blend properties are little better than plain PLA; and with more than 50% PC, the processing temperature is so high it degrades the PLA. Toray is also blending PLA with PP and has a patent application (JP 2005035134) on blends of PLA with up to 25% cellulose from recycled paper to add stiffness. Unitika Ltd. in Japan reinforces PLA with kenaf fiber to improve strength and HDT for use in cell-phone covers, developed with NEC (NEC Corporation, Tokyo, www.nec.com, www.necus.com) An electronics conglomerate known in the U.S. for its monitors. In Japan, it had the lion's share of the PC market until the late 1990s (see PC 98). NEC was founded in Tokyo in 1899 as Nippon Electric Company, Ltd. Corp. in 2006. NEC has applied for a patent on using long kenaf fibers (up to 20 mm) in PLA. Some of Unitika's Terramac PLA-based resins combine nano-additives, plant fibers, and mineral fillers to achieve 70% faster crystallization and shorter molding times than conventional PLA, the company says. Unitika makes patented PLA/PMMA blends in which the PMMA raises the glass-transition temperature (Tg) while retaining clarity. Unitika is also developing PLA alloys with PP and PC. High-temperature grades will be used for dishes and housewares house·wares pl.n. Cooking utensils, dishes, and other small articles used in a household, especially in the kitchen. . Polymaterial Technology Co. in Thailand (a compounding unit of CPPC CPPC Cost Plus Percentage-of-Cost (contract) CPPC Core Project Planning Committee CPPC Centro di Psicologia e Psicoterapia Costruttivista CPPC Career Program Policy Committee (US Army) Public Co.) introduced heat-resistant PLA/PHA and PLA/PHBV compounds for durable applications last year. These have Tg of up to 80 C for injection molded dishes and housewares. Four commercial EcoHybrid grades are alloys of bio- and petro-based plastics: PLA/PHA/PP, PLA/PHA/TPU, PLA/PHA/PETG, and PLA/PHA/ABS. Polymaterial has also developed PLA/ nylon 6 compounds for durable applications. Also, a hybrid of 30% PLA, 60% PC, and 10% compatibilizer can withstand exposure to more than 120 C, which is suitable for electronics applications, Polymaterial says. Mitsubishi Plastics Mitsubishi Plastics, Inc. (三菱樹脂株式会社 in Japan has applied for a patent (WO 200422650) on a combination of PLA with titanate-treated metal hydroxides, talc, a char-forming flame retardant Flame retardants are materials that inhibit or resist the spread of fire. Naturally occurring substances such as asbestos as well as synthetic materials, usually halocarbons such as polybrominated diphenyl ether (PBDEs), polychlorinated biphenyls (PCBs) and chlorendic acid , and other fillers for toughness and flame retardance. Mitsubishi is reportedly developing a PLA-based compound for household appliances. Samsung Cheil Industries in Korea alloys PLA with PC or ABS for durable applications like cell phones, three models of which were commercialized last year. Cheil's biomaterials are now being tested by General Motors and Ford. [ILLUSTRATION OMITTED] Stream Source Technologies in Shanghai, China, injection molds heat-resistant PLA consumer products that look and feel like melamine melamine (mĕl`əmēn'), common name for 2,4,6-triamino-1,3,5-triazine. Melamine is a trimer (see polymer) of cyanamide, H2NC≡N, and is synthesized from calcium carbide. . Instead of alloying PLA with other polymers, Stream Source uses nucleating agents to increase heat resistance and mechanical properties. Stream Source also makes mineral-reinforced PLA hangers hangers used for hanging x-ray films to dry. There is a clip type, with a clip at each corner, and a channel type in which the film sits in channels in the sides of the frame. for Rubbermaid. The compostable hangers are sold through Wal-Mart. Stream Source technical director Jason Whelan notes that PEA doesn't have a brittleness problem if it's properly dried to less than 250 ppm of moisture before processing. HIGH-HEAT COPOLYMERS PLA copolymers are being developed to combine the standard "right-handed" L-lactide monomer monomer (mŏn`əmər): see polymer. monomer Molecule of any of a class of mostly organic compounds that can react with other molecules of the same or other compounds to form very large molecules (polymers). and the rarer "left-handed" D-lactide monomer. The result is stereocomplex PLLA/PDLA copolymers that have higher strength, crystallinity, and heat resistance. HDT is 320 F for a 50/50 copolymer copolymer: see polymer. , vs. 140 F for conventional amorphous PLA. Teijin Ltd. in Japan will introduce this year high-heat stereocomplex PLA called Biofront for fibers and automotive. It has a melting point melting point, temperature at which a substance changes its state from solid to liquid. Under standard atmospheric pressure different pure crystalline solids will each melt at a different specific temperature; thus melting point is a characteristic of a substance and of 410 F, vs. 338 F for standard PLA. Tate & Lyle in the U.K. acquired a patented process to copolymerize co·pol·y·mer·ize v. co·pol·y·mer·ized, co·pol·y·mer·iz·ing, co·pol·y·mer·iz·es v.tr. To polymerize (different monomers) together. v.intr. To react to form a copolymer. stereo-complex PLA two years ago, but the project is on hold for now. STARCHED & READY TO GO Industrial starch from corn, tapioca, rice, and even potatoes is plentiful and cheap. Starch can be chemically processed to turn it into a thermoplastic A polymer material that turns to liquid when heated and becomes solid when cooled. There are more than 40 types of thermoplastics, including acrylic, polypropylene, polycarbonate and polyethylene. . Cereplast compounds starch with PP into four grades of BioPP for durable applications. These 50/50 blends are reactively compounded at Cereplast's 50-million-lb/yr semi-works plant into three injection grades and one grade for thermoformable sheet or injection molding injection molding n. A manufacturing process for forming objects, as of plastic or metal, by heating the molding material to a fluid state and injecting it into a mold. . BioPP reportedly has interesting properties of printability, soft touch, static dissipation, and heat resistance similar to conventional PP. Cereplast will toll compound BioPP for a half-dozen PP producers to make custom biopolymers for them at its new plant in Seymour. Ind., which starts up early this year. The first of these will appear commercially early this year. Scrap BioPP can be reprocessed with virgin BioPP or with PP copolymers. BioPP scrap could also go into polyolefin decking. Later this year, Cereplast will introduce Bio-PS and Bio-PE, which will combine 50/50 starch and HIPS or HDPE HDPE abbr. high-density polyethylene . Starch bonds readily to PP. but not to PS and PE. so the latter two will require compatibilizing. Cereplast is also developing a thermoplastic composite of wood fiber, starch. and other organic ingredients to make sheet and profiles for interior woodwork and cabinetry. Cerestech Inc., a technology licensing company spun off from the Ecole Polytechnique of Montreal. last month licensed its starch-based alloy technology exclusively to Teknor Apex Co. Teknor plans to use the technology to produce blends of thermoplastic starch with biopolymers like PLA or PHA and with polyolefins. Some compounds will be aimed at durable applications. The first should be commercial this year. Teknor will also license the technology to large-volume processors for in-house compounding. Cerestech's patented process (U.S. Pat. 6605657 and 6844380) plasticates starch in one extruder and then combines it with a synthetic polymer Synthetic polymers are often referred to as "plastics", such as the well-known polyethylene and nylon. However, most of them can be classified in at least three main categories: thermoplastics, thermosets and elastomers. coming from a second extruder. The process (U.S. Pat. Applic. 20080287592) reportedly makes a continuous matrix of the synthetic polymer containing discontinuous discontinuous /dis·con·tin·u·ous/ (dis?kon-tin´u-us) 1. interrupted; intermittent; marked by breaks. 2. discrete; separate. 3. lacking logical order or coherence. thermoplastic starch domains (0.2 to 1.5 microns). The blend is said to retain or even improve the matrix polymer's properties. LEARN MORE ONLINE Visit www.ptonline.com/articles/200901fa2.html for links to these related articles: PLA Biopolymers: New Copolymers, Expandable Beads, Engineering Alloys & More, Now '08 Enhancing Biopolymers: Additives Are Needed for Toughness, Heat Resistance & Processability, July '08 What's Ahead for Green Plastics, Feb '08 'Green' Is an Added Attraction in Bumper Crop In agriculture, a bumper crop refers to a particularly good harvest yielded for a particular crop. Example: "With all the rain we've had over the last few months, we are expecting a bumper crop this year. of New Plastics, Feb. '08 New Biopolymer Database Want more data on biopolymer material properties? Visit the biopolymers section of PLASTICS TECHNOLOGY's new PLASPEC Global materials database A materials database is a database used to store experimental, standards or design data for materials in such a way that they can be retrieved efficiently by humans or computer programs. at www.ptonline.com/plaspec. It is available through our partnership with M-Base Engineering + Software of Aachen, Germany, which prepared the database for the University of Applied Sciences in Hannover, Germany, with support from the German government. The biopolymer database contains over 300 materials from 60 suppliers, including some that are biodegradable but not bio-derived and others that are only partly bio-derived, as well as some additives for biopolymers and some film and sheet bioplastic materials. The biopolymer database will be continually updated with new materials, and the University and M-Base are now testing these materials according to CAMPUS international standard protocols. The latter will provide the first truly comparable properties for biomaterials from different suppliers. CONTACT SUPPLIERS For more information on these companies and their products, visit www.PTonline.com/suppliers. Cereplast, Hawthorne, CA (310) 676-5000 * www.cereplast.com Cerestech Inc., Montreal, QC (514) 893-2089 * www.cerestech.ca Gehr Plastics Inc., Boothwyn, PA (610) 497-8941 * www.gehrplastics.com Mitsubishi Plastics Inc., Tokyo, Japan +81 (3) 3279-3800 * www.mpi.co.jp NatureWorks LLC NatureWorks LLC is a stand-alone company, wholly owned by Cargill that produces a family of polymers derived entirely from annually renewable resources designed to compete with petroleum-based packaging materials and fibers. , Minnetonka, MN (952) 420-0400 * www.natureworksllc.com Polymaterial Technology Co., Bangkok, Thailand +66 (2) 625-7145 * www.biopmtc.com Samsung Chemical (USA) Inc., Schaumburg, IL (847) 407-2849 * www.samsungchemicalusa.com Specialty Minerals Inc., Bethlehem, PA (610) 861-3428 * www.specialtyminerals.com Tale & Lyle Ingredients, Decatur, IL (217) 423-4411 * www.tateandlyle.com Teijin Kasei America Inc., Norcross, GA (770) 346-8949 * www.teijinkasei.com Teknor Apex Co. Pawtucket, RI (401) 725-8000 * www.teknorapex.com Telles, Lowell, MA (478) 513-1800 * www.mirelplastics.com Tianan Biologic Materials Co., Wayzata, MN (952) 476-2987 * www.tianan-enmat.com Toray Industries (Americas) Inc., NYC NYC abbr. New York City NYC New York City (212) 697-8150 * www.torayusa.com Unitika America Ltd., Erlanger, KY (859) 372-6633 * www.unitika.co.jp
TABLE 1--Experimental PLA Alloys
BLEND PLA/PC PLA/ABS PLA/ABS
ENGINEERED CALIBER (b) MAGNUM (b) MAGNUM (b)
RESIN 200-22 555 555
ENG. RESIN % 20 20 80
TENS. YIELD, PSI 9130 9730 10,625
ELONG., % 3.0 4.0 5.1
TENS. MOD., KPSI 411 454 447
HDT, F @66 PSI 138 136 163
NOTCHED IZOD,
FT-LB/IN. 0.35 0.33 0.29
CLEAR NO YES YES
BLEND PLA/PMMA PLA/PMMA PLA (a)
ENGINEERED PARALOID (c) PARALOID (c) --
RESIN CA-86 CA-86 --
ENG. RESIN % 20 80 0
TENS. YIELD, PSI 7950 6660 9150
ELONG., % 2.9 4.9 3.5
TENS. MOD., KPSI 414 343 430
HDT, F @66 PSI 136 192 138
NOTCHED IZOD,
FT-LB/IN. 0.48 0.59 0.35
CLEAR NO NO YES
(a) Nature Works Ingeo Biopolymer 2002D. (b) Dow Chemical.
(c) Rohm & Haas
(Source: Nature Works white paper by
D. Henton & R.C. Bopp, 2/7/2007)
TABLE 2--Unitika Terramac Modified PLA
TYPE HEAT- HEAT- HEAT
RESISTANT RESISTANT RESISTANT
GRADE TE-7000 TE-7307 TE-7300
DENSITY, G/CC 1.27 1.42 1.47
MELT TEMP, F 338 338 338
ELONG. @ BREAK, % 2 2 1
TENS. STR. @ BREAK,
PSI 10,150 >7830 7830
FLEX. MOD., KPSI 667 1087 1377
HDT, F @66 PSI 230 248 284
NOTCHED CHARPY
IMP., KJ/[M.sup.2] 2.0 2.5 2.4
HEAT HEAT
RESISTANT RESISTANT
TYPE HIGH HIGH
DURABILITY DURABILITY
GRADE TE-8210 TE-8300
DENSITY, G/CC 1.42 1.47
MELT TEMP, F 338 338
ELONG. @ BREAK, % 2 1
TENS. STR. @ BREAK,
PSI 7250 8120
FLEX. MOD., KPSI 986 1348
HDT, F @66 PSI 248 284
NOTCHED CHARPY
IMP., KJ/[M.sup.2] 4.0 2.8
TABLE 3--Polymaterial Technology
Compatibilized PLA/PC
GRADE ECOHYBRID
C510
DENSITY, G/CC 1.10-1.25
MR, G/10 MIN @ 482 F 25-35
TENS. STRENGTH, PSI 7250-9425
ELONGATION @ BREAK, 1/0 10-20
FLEX. STRENGTH, PSI 10,150-12,325
FLEX. MOD., KPSI 377-392
IZOD IMPACT STR., J/M 625-650
HDT, F @ 66 PSI 212
TABLE 4--Samsung Cheil PC-PLA
Alloys vs. PC/ABS
GRADE GL-1355S GL-1455S RP-1001N
POLYMER PC/PLA PC/PLA PC/ABS
BIO % 35 45 0
DENSITY,
G/CC 1.18 1.18 1.15
TENS. STR.,
PSI 7100 7700 7800
FLEX. STR.,
PSI 10,700 11,400 11,100
FLEX. MOD.,
KPSI 291 335 298
NOTCHED IZOD,
FT-1-13/IN. 12.8 12.8 8.3
HDT, F @ 264
PSI 230 167 232
MR, G/10 MIN 45 3 40
TABLE 5--Samsung Chiel ABS/PLA Alloys vs. ABS
GRADE GL-3405H OL-3405S SR-10325
POLYMER ABS/PLA ABS/PLA ABS
TYPE HIGH-IMPACT STANDARD HIGH-TEMP.
BIO % 40 40 0
DENSITY, G/CC 1.11 1.12 1.06
TENS. STR., PSI 6400 6500 7000
FLEX. MOD., KPSI 285 317 312
NOTCHED IZOD, FT-LB/IN. 5.50 1.10 2.80
HDT, F @ 66 PSI 216 230 266
MR. G/10 MIN 8 20 8
TABLE 6--Cereplast 50/50 Thermoplastic Starch/PP Alloys
SHADE BIOPP-50E BIOPP-265-001
TYPE INJECTION THERMOFORMING
610% 50 50
DENSITY, G/CC 1.04 1.03
ELONGATION @ BREAK, % 2-6 18
TENS. STR.@ YIELD, PSI -- 2520
FLEX. STR., PSI -- 3140
FLEX. MOD., KPSI 250-280 100
NOTCHED IZOD, FT-LB/IN. 0.5-0.7 1.03
HDT, F @ 66 PSI 270-277 --
MFR, G/10 MIN 12-18 8
BIOPP-
SHADE 265-002-2 BIOPP-265-003
TYPE INJECTION INJECTION
610% 50 50
DENSITY, G/CC 1.00 1.00
ELONGATION @ BREAK, % 5.6 6.2
TENS. STR.@ YIELD, PSI 2360 2100
FLEX. STR., PSI 2780 2900
FLEX. MOD., KPSI 90 95.5
NOTCHED IZOD, FT-LB/IN. 0.61 0.56
HDT, F @ 66 PSI -- --
MFR, G/10 MIN 45 28
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