芳纶纤维kevlar.docx

芳纶纤维kevlar.docx

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芳纶纤维kevlar

芳纶纤维（kevlar）

Aramidfiber

Aramidfiberiscalled"p-polyphenyltwobenzoyltwoofbenzeneamine,EnglishAramidfiber（DuPontCobrandnameKevlarKevlar）,isanewtypeofhigh-techsyntheticfiber,hasexcellentpropertiesofultrahighstrength,highmodulusandhightemperatureresistance,acidresistanceandalkaliresistance,lightweight,thestrengthofsteelwire5~6timesthemodulusofsteelwireorglassfiberis2~3times,2timesthetoughnessofsteelwire,steelwireandtheweightisonlyabout1/5,doesnotdecomposeatatemperatureof560degrees,anddoesnotmelt.Ithasgoodinsulationandanti-agingproperties,andhasalonglifecycle.Thediscoveryofaramidfiberisconsideredasaveryimportanthistoricalprocessinthefieldofmaterials.

1.introduction

Aramidfiberisanimportantmaterialfornationaldefense,inordertomeettheneedsofmodernwar,atpresent,thedevelopedcountriessuchastheUSandBritain'sbulletproofvestsaremadeofKevlararamidfiber,lightweightbodyarmor,helmets,effectivelyimprovethearmy'srapidresponsecapabilityandlethality.IntheGulfWar,AmericanandFrenchaircraftmadeextensiveuseofKevlarcomposites.Inadditiontomilitaryapplications,ithasbeenwidelyusedinmanyfields,suchasaerospace,aviation,mechanicalandelectrical,construction,automobile,sportinggoodsandotheraspectsofthenationaleconomy.Inaviation,aerospace,aramidduetolightweightandhighstrength,savingfuelamount,accordingtoforeigninformation,duringthelaunchofspacecraft,eachtoreducetheweightof1kg,asameansofreducingthecostof$1million.Inaddition,therapiddevelopmentofscienceandtechnologyisopeningupmorenewcivilianspaceforaramid.Asreportgoes，

Atpresent,aramidproductsareusedinbulletproofvests,helmetsandotheraccountsfor7~8%,aerospacematerials,sportsmaterialsaccountedforabout40%;tyrematerial,conveyorbeltmaterialetc.about20%,thereareabout13%highstrengthropeetc..

2.classification

Aramidfiberismainlydividedintotwotypes,paraaramidfiber（PPTA）andmetaaramidfiber（PMIA）,since1960sbyDuPont（DuPont）companyhassuccessfullydevelopedthearamidfiberandthefirstindustry,inthepast30years,aramidfiberhasahistorybymilitarystrategysuppliestotheciviliangoodstransfer,pricesalsofellbynearlyhalf.Now,foreignaramidfiber,whetheritisR&Dlevelorlarge-scaleproduction,ismaturing.Aramidfiberdevelopsfastestinthefieldofaramidfiberproduction,mainlyinJapanandtheUnitedStatesandeurope.SuchasDuPontKevlarfiber,HollandAKZONOBEL（AkzoNobel）（thecompanyhaswiththemergerofTwaronfiber,Teijin）JapanTeijincompanyTechnoraandRussia'sTerlonfiberfiber.ThevarietiesofaramidfiberareNomex,Conex,Fenelonfiberandsoon.TheUnitedStatesDuPontpioneerofaramidfiberdevelopment,theybothintheresearchanddevelopmentofnewproducts,productionscale,orinthemarketshareistheworldfirst-classlevel,onlytheirproductionofKevlarfiber,thereareKevlar49,Kevlar29andmorethan10grades,eachgradeandseveraltenspecificationstheproduct.DuPontCoannouncedlastyearthatitwillexpandproductioncapacityofKevlarfiber,whichisexpectedtobecompletedbytheendofthisyear.

Hearst,Teijinaramidproductionenterprisesalsohaveexpansionornotresignedtoplayingsecondfiddle,combined,andactivelyexplorethemarket,hopingtobecomeaforceinthesunriseindustry.

TheGermanAcordiscompanyrecentlydevelopedahigh-performanceultra-fineparaaramid（Twaron）products,itisnotburning,notmelting,andhighstrengthandgreatHangzhoucuttingability,mainlycanbeusedforavarietyoftextileandgarmentproductionequipmentcoatingandnoncoatingfabric,knittedfabricandneedlefeltbothhightemperatureandanticuttingthe.Twaronsuperfinefilamentfinenessonlyforoccupationsafetyclothing60%commonlyusedaramidfiber,withitsweavingglovesandtheanticuttingabilityofl0%,productionofwovenfabricsandknittedproductswithit,feelsofter,morecomfortabletouse.Twaronanticuttingglovesmainlyusedinautomobilemanufacturingindustry,glassindustryandmetalpartsproductionfactory,productionactivitiesbutalsofortheforestindustrysupport,toprovideantisabotageequipmentsuchaspublictransportindustry.TheuseofflameretardancyandheatresistanceofTwaron,canprovideprotectivesuitsandcarpetandotherequipmentforthefirebrigade,aswellascasting,hightemperaturefurnaces,glassfactoryoperationsdepartmenttoprovideheatfireservice,aswellastheproductionofaircraftseatfireretardantcoatingmaterial.Withthishigh-performancefiber,butalsotocreateautomotivetires,coolinghoses,Vbeltandotherparts,opticalfibercablesandbulletproofvestsandotherprotectiveequipment,butalsoinplaceofasbestosfrictionmaterialsandsealingmaterials.

Accordingtostatisticsofrelevantdepartments,theworldtotaldemandofaramidfiberwas360thousandtons/yearin2001,anditwillreach500thousandtons/yearin2005.Demandforaramidfiberisontheincrease,

Aramidfiber,asanewhigh-performancefiber,hasenteredaperiodofrapiddevelopment.

Comparedwiththeboomingofoverseasaramidfiberindustry,thelocalizationofaramidfiberhasjuststarted.ThearamidfiberinChinastartedlateinthedevelopmentofforeigncompanies,blockadeofthecoretechnologymonopolyandotherreasons,thearamidfiberinChina'stechnicallevel,productqualityandproductioncapacitywiththedevelopedcountriesthereisacertaingap.Itisreportedthatinrecentyears,therapiddevelopmentofChina'selectronics,constructionandtireindustry,makingChina'saramidfiberconsumptionincreasedrapidly.China'saramidfibermadesodifficultfortworeasons:

first,theproductionoftechnicalbottlenecksdifficulttobreak;andtheotheristhatmostoftherawmaterialsneedtoimport,especiallydomesticsolventscannotpass.ButpreciselybecauseitisanewthinginChina,themarketisfarfromsaturated,anditisworthourattentionanddevelopment.Atpresent,thedevelopmentofaramidfiberproductioninChinahasbeenmentionedintheschedule,aramidfiberwasincludedintheStateencouragesthedevelopmentofhightechproducts,thegovernmentwillalso"aramidfiberinengineeringtire,synchronousbeltinthedevelopmentofapplicationtechnology"asChina's"fifteen"rubberindustrymajorresearchandindustrializationproject.Especiallyinthedevelopmentandproductionofaromaticamidesintheproductionline,Chinahasmadeacertainprogress.

Two.Fireretardantaramidfiber1313

Aramid1313wasfirstproposedbytheAmericanDuPontCosuccessfullydeveloped,andin1967achievedindustrialproduction,theproductisregisteredasaNomex®（Nomex）.Thisisasoft,fluffy,shinywhiteslenderfibers,aswiththegeneralappearanceofchemicalfiber,

Buttheyaremorethanone,withextraordinaryfeatures":

1.lastingthermalstability.

ThecharacteristicsofAramid1313isthemostoutstandinghightemperatureresistantperformanceisgood,canbeusedinthehightemperatureof220DEGCwithoutaginglong-term,theeffectivenessoftheelectricandmechanicalperformancecanbemaintainedfor10years,andexcellentdimensionalstability,thermalshrinkageat250degreesaroundtherateofonly1%,ashorttimeexposureto300DEGChightemperaturewillnotshrink,embrittlement,softeningormelting,onlythestrongXiacaitemperatureover370DEGto400DEGCtodecomposecarbide,suchahighthermalstabilityinthepresentistheuniquetemperatureresistantorganicfiber.

2.,excellentflameretardancy

Weknowthatthepercentageofoxygenrequiredforcombustionofmaterialsintheairiscalledthelimitingoxygenindex,andthegreaterthelimitingoxygenindex,thebettertheflameretardancy.Generally,theoxygencontentinairis21%,whilethelimitoxygenindexofaramidfiber1313isgreaterthan28%.Itbelongstononflammablefiber,soitdoesnotburninair,nordoesitsupportcombustionandhasselfextinguishing.TheinherentpropertyofthemolecularstructuremakesAramid1313permanentflameretardant,soithasthenameof"fireretardantfiber".

3.excellentelectricalinsulation.

Aramid1313lowdielectricconstant,dielectricstrengthinherenttomaintainexcellentelectricalinsulationareinhightemperature,lowtemperatureandhighhumidityconditions,thepreparationofthepaperinsulationbreakdownvoltagecanreach100thousandvolts/L,isthebestinsulatingmaterialsgloballyrecognized.

4.outstandingchemicalstability

Aramid1313isalinearmacromoleculecomposedofaromaticgroupsconnectedbyamidebonds,

Hydrogenbondsintwoplanesarearrangedinathree-dimensionalstructure,thestronghydrogenbondingmakesitschemicalstructureexceptionallystable,resistanttomosthighconcentratedinorganicacidandotherchemicalcorrosion,antihydrolysisandsteamcorrosion.

5.excellentmechanicalcharacteristics

Aramid1313flexiblepolymermaterials,lowstiffnessandhighelongationcharacteristicsthathavethesamewithordinaryfiberspinnability,canbeprocessedintoavarietyofconventionaltextilefabricsornon-wovenfabrics,andwearandtearresistance,thescopeisveryextensive.Superradiationresistance.

Aramidfiber1313isresistanttoalpha,beta,squareandultravioletrayradiation.With50Kvraysof100hoursradiation,thefiberstrengthremainedtheoriginal73%,whilethepolyesterornylonbecamepowder.Theperformanceofspecialchemicalstructureandstablewitharamidfiber1313excellent,throughthecomprehensiveutilizationofthese