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Rubber presentation (1)

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Rubber presentation (1)

  1. 1. Rubber: History,Rubber: History, Properties and StructureProperties and Structure Katrina CzenkuschKatrina Czenkusch Physical Chemistry of MacromoleculesPhysical Chemistry of Macromolecules April 9, 2009April 9, 2009
  2. 2. Definition of Rubber/Definition of Rubber/ElastomerElastomer ““A material that can be stretched to atA material that can be stretched to at least twice its original length and willleast twice its original length and will retract rapidly and forcibly to substantiallyretract rapidly and forcibly to substantially its original dimensions upon release of theits original dimensions upon release of the force.force.”” Rosen; p389Rosen; p389
  3. 3. Natural Rubber: Where?Natural Rubber: Where? Hevea brasiliensisHevea brasiliensis –– Most common sourceMost common source –– Responds to wounding by producingResponds to wounding by producing more latexmore latex –– Produces cisProduces cis--1,41,4--polyisoprenepolyisoprene –– Native to Amazon RainforestNative to Amazon Rainforest GuttaGutta--PerchaPercha –– Produces transProduces trans--1,41,4--polyisoprenepolyisoprene –– Native to MalaysiaNative to Malaysia Rubber Plantations in MalaysiaRubber Plantations in Malaysia Pictures: http://en.wikipedia.org/wiki/Natural_rubber
  4. 4. Rubber in PrehistoryRubber in Prehistory 60 million BC60 million BC –– EuropeEurope -- rubberrubber--producing plantsproducing plants First millennium BCFirst millennium BC –– MexicoMexico –– First evidence of theFirst evidence of the Mesoamerican ballgameMesoamerican ballgame 66thth centurycentury –– Mexico and CentralMexico and Central AmericaAmerica –– Aztecs/MayansAztecs/Mayans –– BallsBalls –– Dipped Feet to make shoesDipped Feet to make shoes –– Coated FabricsCoated Fabrics Pictures: http://en.wikipedia.org/wiki/Mesoamerican_ballgame
  5. 5. Rubber and EuropeRubber and Europe First European exposureFirst European exposure –– Columbus supposedly watched aColumbus supposedly watched a Mesoamerican ballgameMesoamerican ballgame –– Early explorers learned nativeEarly explorers learned native waterproofing techniqueswaterproofing techniques Charles Marie de la CondamineCharles Marie de la Condamine and Francois Fresneauand Francois Fresneau –– Popularized rubber in FrancePopularized rubber in France starting mid 1730starting mid 1730’’ss –– Discovered first solventsDiscovered first solvents –– Wrote about propertiesWrote about properties Picture: http://en.wikipedia.org/wiki/Charles_Marie_de_La_Condamine
  6. 6. VulcanizationVulcanization 18391839 –– Goodyear and HancockGoodyear and Hancock –– Mixed natural rubber, sulfur and white lead on a hotMixed natural rubber, sulfur and white lead on a hot stovestove –– Rubber wasRubber was ‘‘curedcured’’ of all its defectsof all its defects 18461846 –– AlexanderAlexander ParkesParkes invented a coldinvented a cold--cure process usingcure process using sulfur chloride gas in solutionsulfur chloride gas in solution [ ]n [CH3 R'R + S8 S CH3 R 2 R 3 S S CH3 R R 1 2-8 Sulfurs ] ][
  7. 7. Natural Rubber the Real StoryNatural Rubber the Real Story 18601860 -- Williams (UK)Williams (UK) –– Decomposed naturalDecomposed natural rubber to isoprenerubber to isoprene 18791879 -- BouchardatBouchardat (France)(France) –– Repolymerized isoprene toRepolymerized isoprene to make rubbermake rubber 19101910 –– PicklesPickles –– Rubber is made of longRubber is made of long chains of isoprenechains of isoprene CH2 CH2 CH3 CH3 R'R [ ]n Isoprene cis-Polyisoprene
  8. 8. Origins of Rubber ElasticityOrigins of Rubber Elasticity Energy elasticityEnergy elasticity –– elongation resultingelongation resulting from rotation around single bonds and thefrom rotation around single bonds and the straining of bond angles and lengthsstraining of bond angles and lengths
  9. 9. Statistics of Ideal Rubber ElasticityStatistics of Ideal Rubber Elasticity Ideal rubberIdeal rubber Slope of the stressSlope of the stress--strain curve or Youngstrain curve or Young’’s Moduluss Modulus –– ρρ = density= density –– R = Gas ConstantR = Gas Constant –– T = temperatureT = temperature –– Mc = number average molecular weight of the networkMc = number average molecular weight of the network chainschains –– αα = extension ratio, l/l= extension ratio, l/l00 –– l/ll/l00 = current length/unstretched length= current length/unstretched length E= ρRT Mc (2α+ α-2)
  10. 10. Deviations from IdealityDeviations from Ideality Under predicts modulus forUnder predicts modulus for αα > 1.5> 1.5 Chain endsChain ends Stress induced crystallizationStress induced crystallization
  11. 11. Butadiene RubberButadiene Rubber PolybutadienePolybutadiene –– First synthesized in 1910 by S. LebedevFirst synthesized in 1910 by S. Lebedev –– Very durable but cis/trans issuesVery durable but cis/trans issues –– Side walls of truck tires and golf ballsSide walls of truck tires and golf balls –– Modern day use is as copolymerModern day use is as copolymer CH2 CH2 cis-1,4-PBD 1,2-PBD trans-1,4-PBD R R 2 CH2
  12. 12. And its copolymersAnd its copolymers Buna N/ Buna NNBuna N/ Buna NN –– Butadiene andButadiene and acrylonitrileacrylonitrile –– Increased acrylonitrileIncreased acrylonitrile increases stiffness andincreases stiffness and oil resistanceoil resistance Buna SBuna S –– Butadiene and styreneButadiene and styrene –– Increased styreneIncreased styrene leads to stiffer rubberleads to stiffer rubber R R N [ ] R R[ ]
  13. 13. The War YearsThe War Years Japan captured Pacific Rubber plantationsJapan captured Pacific Rubber plantations US synthetic rubberUS synthetic rubber –– 19391939 –– 2000 tons/yr2000 tons/yr –– 19451945 –– 830,000 tons/yr830,000 tons/yr –– Butyl rubberButyl rubber German synthetic rubberGerman synthetic rubber –– BeforeBefore –– 22,000 tons/yr22,000 tons/yr –– MiddleMiddle –– 100,000 tons/yr100,000 tons/yr
  14. 14. Butyl RubberButyl Rubber Copolymer of 98% isobuteneCopolymer of 98% isobutene –– 2% isoprene or butadiene2% isoprene or butadiene –– Cationic polymerizationCationic polymerization –– Air impermeableAir impermeable –– Inner tubes for tiresInner tubes for tires CH2 CH3 CH3 R R 1 CH3 CH3R + n
  15. 15. Thermoplastic ElastomersThermoplastic Elastomers Rubbers which canRubbers which can be melt processedbe melt processed afterafter ““crosslinkingcrosslinking”” Immiscible blockImmiscible block copolymerscopolymers –– Form matrix ofForm matrix of rubbery polymer withrubbery polymer with spheres of hardspheres of hard segmentssegments –– Most common:Most common: StyreneStyrene--ButadieneButadiene-- Styrene (SBS)Styrene (SBS) Pictures: http://en.wikipedia.org/wiki/Copolymer
  16. 16. Requirements to make a RubberRequirements to make a Rubber High Molecular WeightHigh Molecular Weight –– Rubber elasticity is due to the coiling/uncoiling of chainsRubber elasticity is due to the coiling/uncoiling of chains Use temperature must be above TgUse temperature must be above Tg –– To allow for molecular motionTo allow for molecular motion Amorphous in its unstretched stateAmorphous in its unstretched state –– Crystals would hinder coiling/uncoilingCrystals would hinder coiling/uncoiling Chains tied together to prevent flowChains tied together to prevent flow –– Traditionally through crosslinkingTraditionally through crosslinking –– Hard/Soft DomainsHard/Soft Domains –– EntanglementsEntanglements All polymers above Tg act as rubbers due to entanglementsAll polymers above Tg act as rubbers due to entanglements However, when the entanglements break, the polymer will begin toHowever, when the entanglements break, the polymer will begin to flowflow
  17. 17. Rubber: History,Rubber: History, Properties and StructureProperties and Structure Katrina CzenkuschKatrina Czenkusch Physical Chemistry of MacromoleculesPhysical Chemistry of Macromolecules April 9, 2009April 9, 2009
  18. 18. ReferencesReferences GoritzGoritz, D., Muller, F. H.,, D., Muller, F. H., SietzSietz, W.;, W.; ““TemperatureTemperature--induced andinduced and StressStress--induced Crystallization in Oriented Polymersinduced Crystallization in Oriented Polymers””,, Progress inProgress in Colloid and Polymer ScienceColloid and Polymer Science; Springer Berlin/Heidelberg, 1977; Springer Berlin/Heidelberg, 1977 Herbert, Vernon;Herbert, Vernon; AttilioAttilio BisioBisio;; Synthetic RubberSynthetic Rubber, Greenwood Press,, Greenwood Press, 19851985 HiemenzHiemenz, Paul C.; Lodge, Timothy P.;, Paul C.; Lodge, Timothy P.; Polymer Chemistry 2Polymer Chemistry 2ndnd ed.,ed., CRC Press; 2007CRC Press; 2007 James, Hubert M.,James, Hubert M., GuthGuth, Eugene;, Eugene; Theory of the Elastic Properties ofTheory of the Elastic Properties of RubberRubber; J. Chem. Phys.; J. Chem. Phys. 11,11, 455 (1943)455 (1943) LoadmanLoadman, John;, John; Tears of the TreeTears of the Tree, Oxford University Press, 2005, Oxford University Press, 2005 Rosen, Stephen L.;Rosen, Stephen L.; Fundamental Principles of Polymeric MaterialsFundamental Principles of Polymeric Materials 22ndnd ed.ed., Wiley, Wiley--Interscience Publication, 1993Interscience Publication, 1993 Solo, Robert;Solo, Robert; Research and Development in the Synthetic RubberResearch and Development in the Synthetic Rubber IndustryIndustry; The Quarterly Journal of Economics;; The Quarterly Journal of Economics; VolVol 68, No.1 (1954)68, No.1 (1954)
  19. 19. From Curiosity to ProductFrom Curiosity to Product (1820(1820--1840)1840) T. HancockT. Hancock –– Pickling MachinePickling Machine –– produceproduce homogeneous rubberhomogeneous rubber ‘‘doughdough’’ –– SpreaderSpreader –– the standardthe standard coating machine used todaycoating machine used today M. FaradayM. Faraday –– Established empirical formulaEstablished empirical formula of natural rubber (Cof natural rubber (C55HH88))
  20. 20. Natural Rubber ProductionNatural Rubber Production Wild ProductionWild Production –– Amazon River and its tributariesAmazon River and its tributaries –– AfricaAfrica 18761876 -- H. WickhamH. Wickham –– Sent 70,000 Hevea seeds to BritainSent 70,000 Hevea seeds to Britain –– 2397 germinated2397 germinated –– Plants sent to Singapore, India, MalaysiaPlants sent to Singapore, India, Malaysia –– Foundation of the eastern rubber plantations (1895)Foundation of the eastern rubber plantations (1895) 19131913--19141914 -- Plantation rubber exceeds wildPlantation rubber exceeds wild

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