高分子化学常见名词

高分子化学常见名词（中英文）SidegroupsAllthecarbonbasedpolymersyouwillfindmentionedonthissitehavethestructure-C-C-C-C-C-C-etc.Anythinghangingoffthatcentrechainthatisnotahydrogenatomisasidegroup.侧基：任何悬挂在高分子主链上的非氢原子均称为侧基。FunctionalGroupAnatomorgroupofatomsthathassimilarchemicalbehavior,nomatterwhattherestofthemoleculelookslike.Forexample,thehydroxy(OH)groupinallalcoholshassimilarreactivity,asdoesthethio(SH)groupinallthiols.官能团：分子中存在的一部分原子、原子团或特征结构，容易发生体现分子主要性质的某些特征反应，因此称它们为官能团。HydrogenbondThestrongestattractionbetweentwodipolesiswhenoneorbothoftheminvolvesabondbetweenhydrogenandastronglyelectronegativeatom,likeoxygen,fluorine,ornitrogen.Becausehydrogenonlyhasoneelectron,ifitformsabondwithanelementthatisverykeentograbanelectron,itbecomesmuchmorepositivethananelementthathasplentyofotherelectronslefttohangaroundthepositivelychargednucleus.Dipole-dipoleinteractionsbetweenthesesortofmolecules(likewater{H2O},ammonia{NH3},hydrofluoricacid{HF})aresomuchstrongerthanordinarydipole-dipolebondsthatwegivethemthespecialnameof'hydrogenbonds'.氢键：氢键是极性很强的X－H键上的氢原子与另外一个键上电负性很大的原子上的孤对电子相互吸引而形成的一种键。氢键作用力比一般的偶极间相互作用力大。氢键具有饱和性和方向性。MonomerAnysmallmoleculethatcanundergoareactioninwhichitisincorporatedintoalargemoleculecontainingmanysimilarunits.Commonmonomersarevinylacetate,styrene,butadieneandvinylchloride.(Yes,itisappropriatetoconsiderhydrocarbonsaspolymersofmethylene!)单体:能够发生反应生成大分子的小分子物质，最常用的单体如：醋酸乙烯，苯乙烯，丁二烯，氯化乙烯等。（习惯上称亚甲基聚合物为碳氢化合物）PolymerAlargemolecule(molecularweight~10000orgreater)composedofmanysmallermolecules(monomer)covalentlybondedtogether.Someofusthinktheyaremuchbetterthananyofthoselittlemolecules,buttheotherchemistsarealwaystellingussizedoesn'tmatter.聚合物：由许多小分子（单体）通过共价键连接而成的大分子物质（分子量大于1万）。PolymerisationTheprocessinwhichmanysmallmolecules(molecularweight~100)arejoinedtogethertoformafew,muchlargermolecules(molecularweight10000-10000000).Thetwowaysinwhichthishappensarechain-growthandstep-growthpolymerisation.聚合：许多小分子物质（分子量约为100）连接在一起生成高分子（分子量为104－107）的过程。主要有连锁聚合和逐步聚合两大类。FreeRadicalAmemberofthesocialistpartynotcaughtbyMcCarthy'sinquisition.Alsoamoleculewhichhasanoddnumberofelectrons.Theunpairedelectronfeelslonelyandwantstofindafriend.Ifitfindssomethingthatmightbewillingtogiveitanelectronitreactsveryquicklywithit.Moleculessuchasotherradicalsandalkenesturnouttobegoodthingsforradicalstoattack.Thereactionofradicalswiththedoublebondsinalkenesishowsomeofusearnourliving.自由基：化合物中共价键发生均裂时，共价键上两个电子分属于两个基团，这种带独电子的基团呈中性。RadicalChainPolymrizationChainpolymerizationisinitiatedbyareactivespeciesR*producedfromsomecompoundItermedaninitiator.Thereactivespecies,whichmaybeafree-radical,addstoamonomermoleculebyopeningthe-bondtoformanewradical.Theprocessisrepeatedasmanymoremonomermoleculesaresuccessivelyaddedtocontinuouslypropagatethereactivecenter.Polymergrowthisterminatedatsomepointbydestructionofthereactivecenterbyanappropriatereactiondependingonthetypeofreactivecenterandtheparticularreactionconditions.自由基聚合：由一种称为引发剂的化合物产生的反应种所引发的链式聚合。这个带有自由基的反应种通过打开双键加入到单体分子上，从而形成新的自由基。这个过程不断重复，更多的单体连续地加入到反应中心上，形成大的自由基反应中心。当一种破坏反应中心的反应发生时，聚合物增长被终止，这将依赖于反应中心的类型和特定的反应条件。AdditionPolymerisationAlsoknownaschain-growthpolymerisation.Themechanisminwhichlargenumbersofusuallyidenticalsmallmoleculesarejoinedtogethertorapidlyformasinglelargemolecule.Thisinvolvestheadditionofreactivecentre(anion,cation,orunpairedelectron)toamultiplebondtoformanewbondandanewreactivecentre-whichreactswithanothermultiplebond,etcetera...Thefinishedchainthenhangsaroundwithoutreactingwhilemoreofthestartingmaterialreactstoformnewpolymerchains.加成聚合：又称为连锁聚合。聚合机理是，大量的小分子快速地连接在一起形成一个大分子。反应中心（阴离子、阴离子和不成对电子）加成到单体的双键中生成新的键和新的反应中心，之后再与另一个单体反应，以此持续反应下去。当不再反应时，链的增长停止，同时新的反应开始，生成新的聚合物链。InitiatorAcompoundrequiredtostartachainreaction,suchasfree-radicalpolymerisation.Unlikeacatalyst,itisconsumedinthereaction,butonlyasmallquantityisnormallyrequiredsinceonemoleculeofinitiatorcaninitiatethereactionofmanyothermolecules.引发剂：能够引起连锁反应（如自由基聚合）的化合物。与催化剂不同，引发剂在反应中能被消耗掉，但是一般只需要少量的引发剂，因为一个引发剂分子能够引发许多单体分子的反应。BenzoylPeroxideAcommoninitiatorusedtostartchaingrowthpolymerisation.Itundergoesadecompositionreactionattheperoxide(O-O)bond.Hereisapicture:过氧化二苯甲酰（BPO）：用于引发链增长聚合的常用过氧类引发剂，引发时过氧键(O－O)断裂分解。其结构式如下图所示:InitiatorEffciencyTheinitiatorefficiencyfisdefinedasthefractionoftheradicalsformedintheprimarystepofinitiatordecomposition,whicharesuccessfulininitiatingpolymerization.Theinitiatorefficiencyisconsideredexclusiveofanyinitiatorwastagebyinduceddecomposition.引发剂效率：引发剂效率定义为引发剂最初分解形成自由基，并成功引发聚合反应的分数。引发剂效率不包括因诱导分解所浪费的引发剂。ChainTransferAgrowingpolymeristerminatedbythetransferredofahydrogenorotheratomorspeciestoitfromsomecompoundpresentinthesystem-themonomer,initiator,orsolvent,asthecasemaybe.Theseradicaldisplacementreactionsarechain-transferreactions.链转移：氢、其它原子或反应种转移到反应体系的化合物中（单体、引发剂或溶剂），从而导致聚合物增长终止，这种情况称为链转移。这种自由基转移的反应称为链转移反应。KineticChainLengthThekineticchainlengthofaradicalchainpolymerizationisdefinedastheaveragenumberofmonomermoleculesconsumed(polymerized)pereachradical,whichinitiatesapolymerchain.Thisquantitywillobviouslybegivenbytheratio