专业英语--材料部分教学提纲.ppt

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1、专业英语专业英语-材料部分材料部分IntroductiontothecourseAboutthecoursePolymerMaterials(郑学晶郑学晶)MetalMaterials(胡俊华胡俊华)InorganicMaterials(范冰冰范冰冰)MaterialEngineering,NanoMaterials,ScientificLiteratureReading&Writing(陈德良陈德良)AboutmeSichuanUniversityBachelor&MasterInstituteofChemistryChineseAcademyofSciencesPhDTechnologyU

2、niversityofEindhovenTheNetherlandsPostdocZhengzhouUniversityAssociateProfessorinPolymerScience&EngineeringAboutMaterialsLife in the 21st century is ever dependent on anunlimited variety of advanced materials.In ourconsumptiveworld,itiseasytotakeforgrantedthemacro-,micro-,andnanoscopicbuildingblockst

3、hatcompriseanyitemproduced.Wearespoiledbythetechnologythataddsconveniencetoourlives,suchasmicrowaveovens,laptopcomputers,digitalcellphones,and improved modes of transportation.However,werarelytake timetothinkaboutandappreciate the materials that constitute thesemodernengineeringfeats.The term materi

4、al may be broadly defined as anysolid-statecomponentordevicethatmaybeusedto address a current or future societal need.Forinstance,simple building materials such as nails,wood,etc.addressourneedofshelter.Othermoreintangiblematerialssuchasnanodevicesmaynotyetbewidelyprovenforparticularapplications,but

5、will be essential for the further needs of ourcivilization.Althoughtheabovedefinitionincludessolidnanostructuralbuildingblocksthatassembletoformlargermaterials,itexcludescomplexliquidcompoundssuchascrudeoil,whichmaybemoreproperlyconsideredaprecursorformaterials.Materialsscienceisaninterdisciplinaryf

6、ieldapplyingthepropertiesofmattertovariousareasofscienceandengineering.Thisscientificfieldinvestigatestherelationshipbetweenthestructureofmaterialsatatomic or molecular scales and their macroscopicproperties.It incorporates elements of appliedphysicsandchemistry.Materialssciencealsodealswithfundamen

7、tal propertiesandcharacteristicsofmaterials.Example sentences:Various:Chemicalproperties,atthenano-scale,describehowthechainsinteractthroughvarious physicalforces.Apolymersarchitectureaffectsmanyofitsphysicalpropertiesincluding,butnotlimitedto,solutionviscosity,meltviscosity,solubilityinvarioussolve

8、nts.Investigate:Title:Anovelspectroscopicapproachtoinvestigatetransportprocessesinpolymers:inthecaseofwater-epoxysystemIncorporate:Halogenslikechlorineandfluorineareveryrareinnaturalpolymers,butmanysyntheticpolymers incorporatetheseelements.Athermo-responsivepolymerisincorporated intoafuelcellinorde

9、rtomaintainoptimumhydrationofthepolymerelectrolytemembraneExample sentences:ClassesofMaterialsMaterialsscienceencompassesvariousclassesofmaterials,eachofwhichmayconstituteaseparatefield.Thereareseveralwaystoclassifymaterials.Forinstancebythetypeofbondingbetweentheatoms.Thetraditionalgroupsareceramic

10、s,metalsandpolymersbasedonatomicstructureandchemicalcomposition.Newmaterialshasresultedinmoreclasses.Onewayofclassifyingmaterialsis:BiomaterialsCarbonCeramicsCompositematerialsGlassMetalsNanomaterialsPolymersRefractorySemiconductorsThinFilmsFunctionallyGradedMaterialsExamplesentences:Result in,resul

11、ting:Theadditionofahigherratioofcrosslinkingagentwillresultinaveryviscouspolymer.Itservesasasolvent,whichisincorporatedintothepolymerstructure,resultinginlowVOCemissions.Theresultingmixturewassubjecttosonicationfor1mininanicebath.1.IntroductiontoPolymersandPolymerizations(PolymerCompositionandStruct

12、ure,PolymerizationMechanism)2.PolymerPhysics(Chainstructure,aggregatestructure,polymermulticomponentsystems,molecularweightandmolecularweightdistribution)3.PolymerChemistry(Additionandcondensationpolymerization,freeradicalpolymerization,polymerizationprocessing)4.PolymerStructuralAnalysis(SEM,TEM,FT

13、IR,DSC,Mechanicaltests)5.PolymerProcessing(Extrusion,Injectionmolding)ContentsofPolymerMaterialsAPolymerisamacromoleculecomposedofrepeatingstructuralunits.Thesmallmoleculesthatcombinewitheachothertoformpolymermoleculesaretermedmonomers,andthereactionsbywhichtheycombinearetermedpolymerizations.polyme

14、ansmanyandmer=parts.Forexample:Polyethyleneismadebyjoiningmanyethylenemoleculestogether.Theprocessofjoiningiscalledpolymerization.In a polymer,the subunits are typically connected bycovalentchemicalbonds.1Whatarepolymers?monomerpolymer13Likemostothertechnologicaldevelopment,polymerswerefirstusedonan

15、imperialbasis,withonlyveryincompleteunderstandingoftherelationshipsbetweenstructureandproperties.The first used polymers used were naturalproducts that date back to antiquity.The first trulysynthetic polymer was a densely cross-linked materialbasedonthereactionofphenolandformaldehydecalledBakelite.B

16、akelitewasathermoset;thatis,itdidnotflowafter the synthesis was complete.The first syntheticthermoplastics,that is,materials that could flow onheating,were poly(vinyl chloride),polystyrene and nylon66.2HistoricalDevelopmentofPolymersthermo-“热热”thermocouplethermodynamicsthermoformingthermogramthermom

17、eter热电偶热电偶热力学热力学热压成形热压成形温谱图，温度记录图温谱图，温度记录图温度计温度计AboutPolymerPhysicsChain structure of polymers leads on to physical andmechanicalbehavior.Polymerchainshavethreebasicproperties:1.Themolecularweightandmolecularweightdistributionofthemolecules.2.Theconformation(构象构象)ofthechainsinspace.3.Theconfiguratio

18、n(构型构型)ofthechain.3ChainStructureofPolymersConfigurationandconformationThetermconfigurationreferstotheorganizationoftheatomsalongthechain.Someauthorsprefertheterm“microstructure”ratherthanconfiguration.Configurational isomerism(异异构构)involvesthedifferentarrangementsoftheatomsand substituents in a cha

19、in,which can beinterconvertedonlybythebreakageandreformationofprimarychemicalbonds,includingits composition,sequence distribution,stericconfiguration,geometricandsubstitutionalisomerism,andsoon.iso-isomer异构体异构体isobutane异丁烷异丁烷isooctane异辛烷异辛烷isochronous同步的，等时的同步的，等时的isoelectric等电位的等电位的Thetermconformat

20、ionreferstothedifferentarrangementsofatomsandsubstituentsofthepolymer chain brought about by rotationsabout single bonds,which has taken on twoseparatemeanings:(a)thelong-rangeshapeoftheentirechain,and(b)theseveralpossibilities of rotating atoms or shortsegments of chain relative to one another.Exam

21、ples of different polymer conformationsincludes the fully extended planar zigzag,helical,foldedchain,andrandomcoils.include:Other important natural polymers includethe proteins,which are polymers of aminoacids,andthenucleicacids.The subjects include polymer products andapplications,polymermanufactur

22、ing,processingandmachinery.Head-to-HeadandHead-to-TailConfigurationThis involves the difference between head-to-headandhead-to-tailplacementofthemonomericunits,or mers,during polymerization.The head-to-tailstructureofpolystyrenemaybewrittenanditshead-to-headstructuremaybewrittenThe thermodynamically

23、 and spatially preferredstructure is usually the head-to-tail configuration,although most addition polymers contain a smallpercentage of head-to-head placements.If thesynthesisisdeliberatelyarrangedtothatthehead-to-headconfigurationisobtained,thepropertiesofthepolymerarefardifferent.Usingpolyisobuty

24、leneasanexample,the melting temperature of the head-to-headconfigurationwas187oC,whereasthehead-to-tail configuration could only be crystallized understress,andthenwithameltingtemperatureof5oC.The head-to-head and head-to-tail configurationscannot be interchanged without breaking primarychemicalbond

25、s.化学名词中常用词头、词尾与中介符号化学名词中常用词头、词尾与中介符号词头词头与与词词尾尾中文与中文与结结构构举举 例例mono-uni-metha-一，甲一，甲单单体体monomer单轴单轴晶体晶体uniaxial crystal甲甲烷烷methanebi-di-etha-二，乙二，乙联联二苯二苯biphenyl二氧化碳二氧化碳carbon dioxide乙乙烷烷ethanestri-ter-propa-三，丙三，丙三乙三乙酰酰胺胺triacetamide三三氯氯化合物化合物terchloride丙丙烷烷propanetetra-quadric-buta-四，丁四，丁四四氯氯化物化物tet

26、rachloride四价四价quadrivalence丁丁烷烷butane(tobecontinued)hepta-septi-七，庚七，庚庚庚烷烷heptane七价的七价的septivalentocta-八，辛八，辛辛辛烷烷octanenona-九，壬九，壬壬壬烷烷nonanedeca-十，癸十，癸癸癸烷烷decanepenta-quique-五，戊五，戊戊戊烷烷pentane五价五价quiquevalencehex-sexi-六，己六，己己己烷烷hexane六价的六价的sexivalentCopolymersManykindsofpolymerscontaintwokindsofmers.

27、Thesecanbecombinedinvariouswaystoobtaininterestingandoftenhighlyusefulmaterials.Some of the basic copolymernomenclature is presented in Table 1,including some of the trinary copolymers.Theconnectivesincopolymernomenclaturewillbedefinedbelow.Table1.Somecopolymerterminology(术语术语)TypeConnectiveExampleS

28、hort sequencesUnspecifiedStatisticalRandomAlternatingPeriodic-co-stat-ran-alt-per-Poly(A-co-B)Poly(A-stat-B)Poly(A-ran-B)Poly(A-alt-B)Poly(A-per-B-per-C)Long sequencesBlockGraftStar-block-graft-star-Poly A-block-poly BPoly A-graft-poly Bstar-poly ANetworks Cross linkedInterpenetrating-cross-inter-cr

29、oss-poly Across-poly A-inter-cross-poly BAggregateStructureofPolymersThebulkstate,sometimescalledthecondensedorsolidstate,includesbothamorphousandcrystallinepolymers.While amorphous polymers do not contain anycrystallineregions,“crystalline”polymersgenerallyare only semicrystalline,containing apprec

30、iableamountsofamorphousmaterial.Whenacrystallinepolymerismelted,themeltisamorphous.semi-“半半”semi-finalsemi-finishedsemi-opaquesemilethal半决赛半决赛半制成的半制成的半透明的半透明的半致死的半致死的Dependingontemperatureandstructure,amorphouspolymersexhibitwidelydifferentphysicalandmechanical behavior patterns.At low temperatures,

31、amorphouspolymerareglassy,hard,andbrittle.Asthetemperatureisraised,theygothroughtheglass-rubbertransition.The glass transition temperature(Tg)isdefined as the temperature at which the polymersoftensbecauseoftheonsetoflong-rangecoordinated(长长 程程 协协 同同)molecular motion.Linear amorphouspolymersflowabov

32、eTg,whilecross-linkedamorphouspolymersexhibitrubberelasticityaboveTg.TheCrystallineStatePolymers crystallized in the bulk state are never totallycrystalline,aconsequenceoftheirlong-chainnatureandsubsequententanglements.The melting temperature of the polymer,Tm,is alwayshigherthantheglasstransitionte

33、mperature,Tg.Thedevelopmentofcrystallinityinpolymersdependsontheregularityofstructureinthepolymer.Thusisotactic(全全同同)andsyndiotactic(间间同同)polymersusuallycrystallize,whereasatactic(无无规规)polymers,withafewexceptions(wherethesidegroupsaresmallorhighlypolar),donot.Regularstructuresalsoappearinthepolyamid

34、es(nylons),polyesters,andsoon,andthesepolymersmakeexcellentfibers.StructureofCrystallinePolymersTheFringedMicelleModel(缨状微束模型缨状微束模型)TheFoldedChainModel(折叠链模型折叠链模型)TheSwitchboardModel(插线板模型插线板模型)ExtendedChainCrystals(伸直链晶伸直链晶)Spherulites(球晶球晶)TheFringedMicelleModelAccording to the fringed micelle mod

35、el,thecrystallites are about 10 nm long.Thedisordered regions separating the crystallitesare amorphous.The chains wander from theamorphous region through a crystallite,andbackoutintotheamorphousregion.Thechainsare long enough to pass through severalcrystallites,bindingthemtogether.TheFoldedChainMode

36、lIdeally,the molecules fold back and forth withhairpin turns.While adjacent reentry has beengenerallyconfirmedbysmall-angleneutronscattering and infrared studies for single crystals,the present understanding of bulk crystallizedpolymersindicatesamuchmorecomplexsituation.TheSwitchboardModelIntheswitc

37、hboardmodel,thechainsdonothaveareentryintothelamellae(晶晶片片)byregularfolding,but rather reenter more or less randomly.Themodel more or less resembles an old-timetelephoneswitchboard.ExtendedChainCrystalsWunderlich pointed out that in thermodynamicequilibrium the crystalline state has an extendedchain

38、 macroconformation.This extended chainconformation can be brought about by annealingfor long periods of time,particularly underpressure.Duringthistime,thefoldperiodofthelamellaegraduallyincreases.SpherulitesWhen polymer samples are crystallized fromthe bulk,the most obvious of the observedstructures

39、 are the spherulites.As the nameimplies,spherulitesaresphere-shapedcrystallinestructuresthatforminthebulk.Oneof the most important problems to beaddressed concerns the form of the lamellaewithinthespherulite.Spherulitesareremarkablyeasytogrowandobservein the laboratory.Simple cooling of a thin secti

40、onbetween crossed polarizers is sufficient,althoughcontrolledexperimentsareobviouslymoredemanding.It is observed that each spheruliteexhibits an extinction cross,sometimes called aMatresecross.Thisextinctioniscenteredattheoriginof the spherulite,and the arms of the cross areoriented parallel to the

41、vibration directions of themicroscopepolarizerandanalyzer.TheAmorphousStateThe amorphous state is defined as a condensed,noncrystallinestateofmatter.Manypolymersareamorphousunderordinaryuseconditions,includingpolystyreneandpoly(methylmethacrylate).Above the glass transition temperature,if thepolymer

42、isamorphousandlinear,itwillflow,albeitthe viscosity may be very high.If the polymer iscrystalline,itisclearlyasolid.Abovethemeltingtemperature,itbecomesamorphous.Ifthepolymeriscross-linked,thenitneverflows,andneverreallybecomes a liquid,but remains a soft amorphoussolid.MorphologyofMulticomponentPol

43、ymersThere are few miscible polymer blends whichexhibit homogeneous structure.Most polymerblends,grafts,blocks,and IPNs exhibit phaseseparation,formingquitecomplexmorphologies.Itmustbeemphasizedthattheirwideapplicationincommerceariseslargelybecauseofthesynergisticproperties,included by such a phase

44、separatedstructure.Applications have included impact-resistantplastics,thermoplastics,elastomers,coating,andadhesives.PolymerblendTheFigurebelowshowsatypicalmorphologyofbinaryimmiscibleblends,wherethemajorcomponentformsthecontinuousphase,ormatrix.Andtheminorcomponentformsdispersedphase,ordomain.Duri

45、ng the processing of polymer blends,several factors are especially important indeterminingthefinalsizeandshapesoftheminor phase:composition,viscosity ratio,interfacial tension,shear rate/shear stress,andprocessingconditions.Thegeneralproblemofthesizeandshapeofpolymermoleculesstandsattheveryheartof p

46、olymer science and engineering.If themolecular weight and molecular weightdistribution are know along with a goodunderstandingofthepolymerchainconformation,manymechanicalandrheologicalpropertiescanbepredicted.4MolecularWeightsandSizesWhilethequestionofmolecularweightspervadestheentireareaofthechemic

47、alarts,polymershaveclassicallypresentedseveralspecialproblems:1.Themolecularweightsareveryhigh,rangingfromabout25,000to1,000,000g/molorhigher.2.Most polymer molecular weight vary greatlydepending on the method of preparation.Inaddition,mostpolymersarepolydisperse;thatis,thesamplecontainsmorethanones

48、pecies.3.The size of the polymer chain is related to itsconformation.4.Polymer chain conformations are functions oftemperature,solvent,structure,crystallization,extension,andthepresenceofotherpolymers.Thestateofpolymerdependsonthetemperatureandonthetimeallottedtotheexperiment.Whilethis is equally tr

49、ue of for semicrystalline oramorphouspolymers,althoughindifferentways.At low enough temperatures,all amorphouspolymers are stiff and glassy.On warming,thepolymers soften in a characteristic temperaturerangeknownastheglass-rubbertransitionregion.5MolecularMotionsandTransitionsofPolymersAboutPolymerCh

50、emistryDuringthedevelopmentofpolymerscience,twotypesofclassificationshavecomeintouse.One classification is based on polymer structure anddivides polymers into condensation and additionpolymers.The other classification is based on polymerizationmechanismanddividespolymerizationsintostepandchainpolyme