高分子材料與應(yīng)用(英文版)-Chapter-7-Coatings-and-Adhesives課件

高分子材料與應(yīng)用（英文版）Chapter7CoatingsandAdhesives高分子材料與應(yīng)用（英文版）Chapter7Coatin1IntroductionWhatarecoatings?Anysubstancesusedtocoverasurfaceandformedanlayeronto.Morespecifically,coatingsmeanspolymerbasedmaterialsusedtocoverasurface.Fourbasicingredients:

film-formingvehicles,pigments,solvents,andadditives.IntroductionWhatarecoatings?2IntroductionWhyCoatings?

Fordecoration:

Color,Gloss,etc.

Forsomefunctions:

erosionresistance,abrasionresistance,slipcontrol,fungalresistance,etc.ApplicationfieldArchitectureandfurniture(paint,漆);

Originalequipmentsmanufacture(OEM,usedinfactory);

SpecialCoatings(usedoutoffactory,forship,equipmentrepair,roadsignsetc.)IntroductionWhyCoatings?3IntroductionClassification

Basedonresintype:

alkyd,polyurethane,polyester,epoxy,…..Basedonenvironmentimpact:

Traditionalsolventcoatings:VOC→pollution

Environment-friendly:Waterborne,HighSolid,Powder,UV-curing…Basedonfinish(漆；末道漆)system:One-coat,Multicoatprimers,Intermediatecoats,andTopcoatsIntroductionClassification4Introduction

CoatingFormingProcess

1.Surfacecleaningandpretreatment2.Coatingsareapplied

dipping,spraying,electroplating…3.Theyformfilmsandcure

solventevaporation,bakingorairdrying,free-radicalpolymerizationIntroductionCoatin52.CoatingResins

AlkydsSynthesis:

fattyAcid+Polyacid+PolyolAdvantages:

lowcost;interiorexposuresgenerallygood.Disadvantages:

exteriordurabilityonlyfairApplication

finishingmetalandwoodproducts.PolyesterSynthesis:

Polyacid+Polyol+(Styrene)Advantages:

goodinterior&exteriordurabilityDisadvantages:

costishigherApplication:

furniture,appliances,automobiles,magnetwire2components:glass-reinforcedplasticbathtubs,lavatories,boats,cars2.CoatingResinsAlkydsPo6CoatingResinsEpoxiesmedium-tohigh-priced,goodadhesion(primersforautomotive),heatresistance(electricalinsulation),excellenterosionandchemicalresistance.poorultraviolet-lightresistance:usedoutdoors,tendtochalkanddiscolor.Acrylicsoutstandingweatherresistance(architecturalcoatings);lacquersandenamels(thetopcoatsfortheautomotive);excellentexteriordurabilityCoatingResinsEpoxies7CoatingResinsPolyurethanesprice>alkydsbut<epoxies.availableasoil-modified,moisturecuring,blocked,two-component,andlacquers.

abrasion-resistant,flexible,resilient,tough,chemical-resistant,andweather-resistant.

veryimportantfinishesinthetransportationindustry,includesaircraft,automobiles,railroads,trucks,andships;militarylandvehicles,ships,andaircraft(chemical&radiologicalresistance)CoatingResinsPolyurethanes8CoatingResinsChlorinatedrubber

usedasswimmingpoolpaintsandtrafficpaints.Fluorocarbonsnonstickproperties(forcookware).Polyamidestough,wear-resistant,arelativelylowcoefficientoffriction(forofficefurniture)Polyolefinsmoistureproof(forchemical-processingandfood-handlingequipment)CoatingResinsChlorinatedrubb93.PigmentsDefinitioninsolubleparticlesdispersedintheliquidportionofthepaint.Functiongivedesiredcolorandgloss,plusprovide"hidingability"(proportionedtorefractiveIndex)andprotection.ClassificationOrganic,inorganic,metallic;White&Color.3.PigmentsDefinition10

PigmentsPigmentDispersionThreeStepsWetting;separatinglargemass;StabilizingthesmallparticlesStabilizingMechanismsForsolventcoating:Polymeradsorption(entropyexclusion):layer>4.5nmForwater-borncoating:needdispersants;ionicinteraction,hydrophobicandhydrophilicbalance.PigmentsPigmentDispersion11

PigmentsPigmentVolumeConcentration(PVC)CriticalPVC

WithPVC↑(upto>CPVC),thepolymerscannotfillthespacesbetweenpigmentparticles→Holesappears,strength↓,adhesion↓.FactorsthatcontrolCPVCparticlesize↓,CPVC↑;sizedistribution↑,CPVC↑PigmentsPigmentVolumeConcen124.AdditivesFunctionaffectvariousareassuchascolor,waterresistance,slipcontrol,foamcontrol,andgloss.Antioxidant

easilycleavage,formfreeradical;e.g.,Phenoliccompounds,naphthol,primaryandsecondaryamines4.AdditivesFunction13Additives

AssociativethickenersFunction:thickenwater-based(mainlylatex)paintsthroughtheirhydrophobicinteractionwithotherpaintcomponentsThreeproducts:hydrophobicallymodifiedethoxylatedurethanes,HEUR,associativeacrylicthickeners,associativecelluloseetherAdditivesAssociati14AdditivesThickeningMechanism聚氨酯類(lèi)增稠劑的增稠機(jī)理之一在于其分子可以水合溶脹而使水相增稠，其二是具有表面活性劑分子的性質(zhì)，其分子是線(xiàn)性親水鏈兩端接有親油基的高分子化合物，即在結(jié)構(gòu)中具有親水和疏水基團(tuán)。這樣，在它的水溶液濃度超過(guò)一定值時(shí)就形成膠束。膠束能夠與乳液的聚合物粒子、已吸附有分散劑的顏料顆粒相互締合形成空間網(wǎng)狀結(jié)構(gòu)，互相連結(jié)纏繞而使體系粘度增加。因而，聚氨酯類(lèi)增稠劑也稱(chēng)為締合型增稠劑。AdditivesThickeningMechanism聚15AdditivesOtheradditivesAcceleratorCuringagentsLightstabilizersDefoamerDispersingagent(dispersant)WettingagentsSurfactantAdditivesOtheradditives165.Film-formingProcessSolventEvaporationwithsolventvolatilization,viscosity↑,Pigmentmovement↓,sotoplayerwithoutpigments→glossycoatingvolatilizetoofast→toplayerformfilmfirst→coatinglayershrinkageLatexcombinationDifficultytoformglossysurfaceFilmformingTtoolow→molecularmovement↓,latexparticlescannotcombine.Tg↑,Minimumfilmformationtemperature↑.5.Film-formingProcessSolvent17CoatingFilmDefectsLeveling(流平)drivenforce:surfacetension(σ).peakarea:coatinglayer↑→solventvolatilization↓→σ>valleyarea→flowfrompeaktovalley.controlfactors:viscosity,layerthickness.Sagging(流掛)controlfactors:viscosity,layerthicknessSurfaceshrinkage(表面起皺)Surfacevolatilization(cure)>bulk→surfaceformfilmfirst→Surfaceshrinkage

Controlfactors:layerthickness,

volatilization(cure)speed.CoatingFilmDefectsLeveling(186.EnvironmentfriendlycoatingsUV-curablecoatingsLowVOC,minimumthicknesschange6.Environmentfriendlycoatin19BasiccomponentsofUVcurablecoatings

BasiccomponentsofUVcurable20UV-curableCoatingsAdvantagesLowVOC,lowenergycost,lowequipmentinvestment.DisadvantagesThicknesslimit:pigment;polymerizationshrinkagePhotoinitiatorleftover:poorexteriordurability.Applications

printingsinks;papercoatings;photo-resistsforprintedcircuitsandmicroeletronicsUV-curableCoatingsAdvantages21WaterbornecoatingsWater-reduciblecoatingsWater+Solventasfilm-formingvehiclesCanusehighMwResinLownonvolatileweightWater-solublecoatingsWaterassolventLowwaterresistantLatexcoatings(乳膠漆)LowVOC,HighMw.DifficultytoformhighglossycoatingAdditivecomplication:dispersants,thickeners,etc.Usedinarchitecture.WaterbornecoatingsWater-reduc22ElectrocoatingOrganiccoatingsaredepositedonproductsfromanelectrolyticbathResinsmustcontainingchargesAdvantagesanddisadvantagesUniformfilmthicknesses,lowVOC,lesslabor-intensive;highcapitalequipmentcosts,highermaterialcosts,andmorethoroughpretreatment.Application:BottomcoatingforCars;metalproducts.ElectrocoatingOrganiccoatings23PowderCoatingsResintypeThermoplastic&ThermosettingFilmformationonpreheatedproductsCoatingMethodsFluidized-bedpowdercoating.Electrostaticfluidized-bedpowdercoatingElectrostatic-spraypowdercoatingAdvantages&disadvantagesLowVOC;thicknessupto500μm;lowenergycost.ExplosionRisk;cannotbeusedinthermosensitiveproducts.PowderCoatingsResintype24SummaryTraditionalcoatingshavefourbasicingredients.Environment-friendlycoatingshavebrightfuture.Coatingindustriesarereallytechnology-intensive.SummaryTraditionalcoatingsha25ADHESIVESADHESIVES26粘接是用粘合劑將被粘物表面連接在一起的過(guò)程。2surfacescanonlybejoinedwiththeestablishmentofbondsbetweenthem.Theexactnatureofthebonddependsontheadhesiveandthesurfacetobebonded.Itisimportantwhenjoiningmaterialswithtrue

adhesivesthatthesurfacestobecompletely

clean.Evenathincoatingofgreaseorsimilarmaterial

mayreduceconsiderablytheeffectivesurface

tensionofthesurface,impairingthebond.INTRODUCTION粘接是用粘合劑將被粘物表面連接在一起的過(guò)程。2surfa27TYPESOFADHESIVECanbedividedinto3types:a)Naturaladhesives

-canbemadefromanimal,vegetableormineralsources

b)Syntheticresinbasedadhesives

i)Thermosettingadhesives

ii)Thermoplasticsyntheticadhesivesc)inorganicadhesivesTYPESOFADHESIVECanbedivide28COMPONENTSOFADHESIVE(1)粘合物質(zhì)(2)溶劑(3)增粘劑(4)消泡劑(5)增塑劑(6)填料(7)防腐劑(8)稀釋劑COMPONENTSOFADHESIVE(1)粘合物質(zhì)29NaturalAdhesivesANIMALGLUEShavebeenusedforcenturiesincarpentryandjoineryObtainedfromtheskin/bonesofcattleandsheepAnimalgluesusuallysoldinpowderandmeltedin

warmwatertogiveasolutionofsuitableviscosity.Coolingoftheliquidafterapplicationresultsinrapidgelling,producingsomestrengthanddryingfinallyproducesatoughandrigidproduct.Removalofthewaterfromglueduringcuringis

essential;thewoodassistinthisprocess,dueto

absorption.NaturalAdhesivesANIMALGLUES30

Gluedjointsinwoodshouldbeasstrongas

thewood.Dampconditionwillreducestrengthofglue.Animalglueisnotsuitableforexternaluse

unlessadequatelyprotectedfrommoisture.Thegluewillhardengraduallyinthepotbut

canbesoftenedbyreheatingwithwater.Ifafailureoccursinsuchitemsitiseasyto

carryoutrepairsbysofteningthegluewith

water.Gluedjointsinwoodshouldb31AnimalGluesAnimalGlues32CASEINGLUESItisderivedasaprecipitatefromskimmed

milkbytheactionofacids.Gluesareobtainedinpowderformthatalso

containalkalinesolvent,necessarytodissolve

theglueonadditionofwater.Mixingiscarriedoutincoldandsettingis

partlybyevaporationorabsorptionofwater

andpartlybyanaturalgelationprocess.ItsadhesiontoporousmaterialisgoodItsmoistureresistanceissuperiorthananimal

glueCASEINGLUES33CaseinGlue–ADryGlueDerivedFromMilkCaseinGlue–ADryGlueDeriv34VEGETABLEGLUEMadefromstarches(淀粉)ordextrin(糊精)lowcostlimitedstrengthandlimitedmoisture

resistanceGumArabicisawatersolublevegetable

adhesiveoftenusedonstampsandgummed

paperenvelopes.VEGETABLEGLUE35CellulosePowderATypeofVegetableAdhesiveCellulosePowderATypeofVeg36WheatPasteATypeofVegetableAdhesiveWheatPasteATypeofVegetabl37THERMOSETTINGADHESIVESUREAFORMALDEHYDEOneofthecommonestadhesivesinjoineryforgeneralpurposes,producingastrongrigidjointiftheglue-lineisthin.Itprovidesastrongadhesioninapermanentlydryenvironment,curesfast,andisrelativelycheap.THERMOSETTINGADHESIVESUREAFO38Tomaketheadhesive,formaldehydeandurea

inaqueoussolutionareallowedtoreacttogethertoacertainstageandthereactionisthenstoppedwhiletheresinisstillliquid.Theyarebestsuitedforjoiningporousmaterialsuchaswood.Itisusedforfabricationofflushcolours,laminatedtimberanddecorativelaminates.Ithasagoodwaterresistancebutifveryhot

waterorprolongedwettingitcouldbreaksthe

resindown.Tomaketheadhesive,formalde39MELAMINEFORMALDEHYDERESINADHESIVES

Suppliedinpowderform&mixedwithwater

togiveacolourlessresin.Setonheatingto100°CGivegoodweatherresistance&expensive

thanureaformaldehydeadhesiveMELAMINEFORMALDEHYDERESIN40PHENOLFORMALDEHYDEavailableasliquidsthatpolymeriseonheating

totemperatureover100°C.UsedforassemblyofplywoodsheetsTheresinisapplied,thesheetsformedandthe

laminatesisthensubjectedtoahotpressthat

causeshardeninginaperiodofabout5min.Cold-curingphenolicadhesivesarealso

available.CanbeappliedforPlywood,blockboards,

flushdoorsPHENOLFORMALDEHYDE41EPOXYRESINSItformagoodbondwithalmostanymaterial.Itiswidelyusedforstructuraljointsbetween

manytypesofmaterialincludingglass,metal,

thermosettingplasticsandconcrete.HaveexcellentmechanicalstrengthHaveexcellentcreepresistanceResistanttoweather,acids,alkalisandmost

hydrocarbon.EPOXYRESINS42EpoxyResinEpoxyResin43EpoxyResinEpoxyResin44AlkylCyanoacrylateAdhesivesHaveadvantageofpolymerisingveryrapidly

whenspreadinthinfilms.Thereactionbeingcatalysedbywaterintheverysmallquantitiesrequiredwhichispresent

onmostsurfaces.Expensivesousesareconfinedtobondingof

smallobjectshavingsurfacesthatclosely

conformtooneanother.TheyformthebasisofSuperglues.Mustbehandledwithcaretoavoidbondingof

skintissues.AlkylCyanoacrylateAdhesives45THERMOPLASTICADHESIVES

Settingactionofthesemayduetocooling,

solventevaporationoremulsioncoalescence.Thisadhesiveismoreflexiblebutweakerand

morepronetocreepthanthermosetting

adhesives.So,theyarenormallynotusedforstructural

purposes.THERMOPLASTICADHESIVESSettin46POLYVINYLACETATEMostimportantthermoplasticadhesivein

building.Chiefapplicationbeingasawoodadhesivefor

internaluseandasabondingagentforconcrete.MostcommonlyusedinemulsionformThispolymerisobtainedfromacetylene&aceticacid.Theadhesivesetswhenthesolidparticles,on

evaporationorabsorptionofthemoisture,

coheretoformatough,clearfilmwhichisno

longerwatersoluble.POLYVINYLACETATE47PolyvinylAcetateUsedForBookBindingPolyvinylAcetateUsedForBoo48BITUMINOUS(瀝青)ADHESIVES

FormgoodbondswithanumberofmaterialsMoistureresistantFlexibleNaturalorSyntheticrubber&solventsmaybe

includedtogivethedesiredcombinationof

elasticityandstrength.Canbeobtainedin3formthatis

a)WaterBasedEmulsion

b)SolventTypesc)Hot-AppliedVarietiesBITUMINOUS(瀝青)ADHESIVES49WaterBasedEmulsions

-Formaneffectivebondbetweenporous

materialsinsituationswherelongtermtensile

stressesarenotpresent.

-Alsousedforlayingwood-blockflooringand

PVCorthermoplastictilesHot-AppliedVarieties

-Usedforwood-blockflooringandin

built-upfeltroofing.

-Applicationtemperatureintheregionof

150°C–200°CWaterBasedEmulsions

-Form50SolventTypes

-UsedinlayinglinoleumandforPVCandthermoplastictilesthoughtestshouldbecarriedouttoensurethatstainingdoesn’toccur. -Bothsolventandemulsiontypesrelyonsomedegreeofabsorbencyinthesubstratetoallowabsorption/evaporationofthewaterorsolvent.SolventTypes

-Usedinlayin51RUBBERBASEDADHESIVESThemostimportantrubberbasedadhesivesintheconstructionindustryarecontactadhesivesTheadhesiveisappliedtobothsurfacesandaftersolventevaporation,thesurfacesarecarefullybroughttogether,givingimmediateauto-adhesion.Latexessuchasstyrenebutadienerubber(SBR)arewidelyusedforfloorcoverings.Latex-modifiedcementsareusedforbondingceramictilestoavarietyofbackgrounds,includingmetal.RUBBERBASEDADHESIVES52ThankYouThankYou53高分子材料與應(yīng)用（英文版）Chapter7CoatingsandAdhesives高分子材料與應(yīng)用（英文版）Chapter7Coatin54IntroductionWhatarecoatings?Anysubstancesusedtocoverasurfaceandformedanlayeronto.Morespecifically,coatingsmeanspolymerbasedmaterialsusedtocoverasurface.Fourbasicingredients:

film-formingvehicles,pigments,solvents,andadditives.IntroductionWhatarecoatings?55IntroductionWhyCoatings?

Fordecoration:

Color,Gloss,etc.

Forsomefunctions:

erosionresistance,abrasionresistance,slipcontrol,fungalresistance,etc.ApplicationfieldArchitectureandfurniture(paint,漆);

Originalequipmentsmanufacture(OEM,usedinfactory);

SpecialCoatings(usedoutoffactory,forship,equipmentrepair,roadsignsetc.)IntroductionWhyCoatings?56IntroductionClassification

Basedonresintype:

alkyd,polyurethane,polyester,epoxy,…..Basedonenvironmentimpact:

Traditionalsolventcoatings:VOC→pollution

Environment-friendly:Waterborne,HighSolid,Powder,UV-curing…Basedonfinish(漆；末道漆)system:One-coat,Multicoatprimers,Intermediatecoats,andTopcoatsIntroductionClassification57Introduction

CoatingFormingProcess

1.Surfacecleaningandpretreatment2.Coatingsareapplied

dipping,spraying,electroplating…3.Theyformfilmsandcure

solventevaporation,bakingorairdrying,free-radicalpolymerizationIntroductionCoatin582.CoatingResins

AlkydsSynthesis:

fattyAcid+Polyacid+PolyolAdvantages:

lowcost;interiorexposuresgenerallygood.Disadvantages:

exteriordurabilityonlyfairApplication

finishingmetalandwoodproducts.PolyesterSynthesis:

Polyacid+Polyol+(Styrene)Advantages:

goodinterior&exteriordurabilityDisadvantages:

costishigherApplication:

furniture,appliances,automobiles,magnetwire2components:glass-reinforcedplasticbathtubs,lavatories,boats,cars2.CoatingResinsAlkydsPo59CoatingResinsEpoxiesmedium-tohigh-priced,goodadhesion(primersforautomotive),heatresistance(electricalinsulation),excellenterosionandchemicalresistance.poorultraviolet-lightresistance:usedoutdoors,tendtochalkanddiscolor.Acrylicsoutstandingweatherresistance(architecturalcoatings);lacquersandenamels(thetopcoatsfortheautomotive);excellentexteriordurabilityCoatingResinsEpoxies60CoatingResinsPolyurethanesprice>alkydsbut<epoxies.availableasoil-modified,moisturecuring,blocked,two-component,andlacquers.

abrasion-resistant,flexible,resilient,tough,chemical-resistant,andweather-resistant.

veryimportantfinishesinthetransportationindustry,includesaircraft,automobiles,railroads,trucks,andships;militarylandvehicles,ships,andaircraft(chemical&radiologicalresistance)CoatingResinsPolyurethanes61CoatingResinsChlorinatedrubber

usedasswimmingpoolpaintsandtrafficpaints.Fluorocarbonsnonstickproperties(forcookware).Polyamidestough,wear-resistant,arelativelylowcoefficientoffriction(forofficefurniture)Polyolefinsmoistureproof(forchemical-processingandfood-handlingequipment)CoatingResinsChlorinatedrubb623.PigmentsDefinitioninsolubleparticlesdispersedintheliquidportionofthepaint.Functiongivedesiredcolorandgloss,plusprovide"hidingability"(proportionedtorefractiveIndex)andprotection.ClassificationOrganic,inorganic,metallic;White&Color.3.PigmentsDefinition63

PigmentsPigmentDispersionThreeStepsWetting;separatinglargemass;StabilizingthesmallparticlesStabilizingMechanismsForsolventcoating:Polymeradsorption(entropyexclusion):layer>4.5nmForwater-borncoating:needdispersants;ionicinteraction,hydrophobicandhydrophilicbalance.PigmentsPigmentDispersion64

PigmentsPigmentVolumeConcentration(PVC)CriticalPVC

WithPVC↑(upto>CPVC),thepolymerscannotfillthespacesbetweenpigmentparticles→Holesappears,strength↓,adhesion↓.FactorsthatcontrolCPVCparticlesize↓,CPVC↑;sizedistribution↑,CPVC↑PigmentsPigmentVolumeConcen654.AdditivesFunctionaffectvariousareassuchascolor,waterresistance,slipcontrol,foamcontrol,andgloss.Antioxidant

easilycleavage,formfreeradical;e.g.,Phenoliccompounds,naphthol,primaryandsecondaryamines4.AdditivesFunction66Additives

AssociativethickenersFunction:thickenwater-based(mainlylatex)paintsthroughtheirhydrophobicinteractionwithotherpaintcomponentsThreeproducts:hydrophobicallymodifiedethoxylatedurethanes,HEUR,associativeacrylicthickeners,associativecelluloseetherAdditivesAssociati67AdditivesThickeningMechanism聚氨酯類(lèi)增稠劑的增稠機(jī)理之一在于其分子可以水合溶脹而使水相增稠，其二是具有表面活性劑分子的性質(zhì)，其分子是線(xiàn)性親水鏈兩端接有親油基的高分子化合物，即在結(jié)構(gòu)中具有親水和疏水基團(tuán)。這樣，在它的水溶液濃度超過(guò)一定值時(shí)就形成膠束。膠束能夠與乳液的聚合物粒子、已吸附有分散劑的顏料顆粒相互締合形成空間網(wǎng)狀結(jié)構(gòu)，互相連結(jié)纏繞而使體系粘度增加。因而，聚氨酯類(lèi)增稠劑也稱(chēng)為締合型增稠劑。AdditivesThickeningMechanism聚68AdditivesOtheradditivesAcceleratorCuringagentsLightstabilizersDefoamerDispersingagent(dispersant)WettingagentsSurfactantAdditivesOtheradditives695.Film-formingProcessSolventEvaporationwithsolventvolatilization,viscosity↑,Pigmentmovement↓,sotoplayerwithoutpigments→glossycoatingvolatilizetoofast→toplayerformfilmfirst→coatinglayershrinkageLatexcombinationDifficultytoformglossysurfaceFilmformingTtoolow→molecularmovement↓,latexparticlescannotcombine.Tg↑,Minimumfilmformationtemperature↑.5.Film-formingProcessSolvent70CoatingFilmDefectsLeveling(流平)drivenforce:surfacetension(σ).peakarea:coatinglayer↑→solventvolatilization↓→σ>valleyarea→flowfrompeaktovalley.controlfactors:viscosity,layerthickness.Sagging(流掛)controlfactors:viscosity,layerthicknessSurfaceshrinkage(表面起皺)Surfacevolatilization(cure)>bulk→surfaceformfilmfirst→Surfaceshrinkage

Controlfactors:layerthickness,

volatilization(cure)speed.CoatingFilmDefectsLeveling(716.EnvironmentfriendlycoatingsUV-curablecoatingsLowVOC,minimumthicknesschange6.Environmentfriendlycoatin72BasiccomponentsofUVcurablecoatings

BasiccomponentsofUVcurable73UV-curableCoatingsAdvantagesLowVOC,lowenergycost,lowequipmentinvestment.DisadvantagesThicknesslimit:pigment;polymerizationshrinkagePhotoinitiatorleftover:poorexteriordurability.Applications

printingsinks;papercoatings;photo-resistsforprintedcircuitsandmicroeletronicsUV-curableCoatingsAdvantages74WaterbornecoatingsWater-reduciblecoatingsWater+Solventasfilm-formingvehiclesCanusehighMwResinLownonvolatileweightWater-solublecoatingsWaterassolventLowwaterresistantLatexcoatings(乳膠漆)LowVOC,HighMw.DifficultytoformhighglossycoatingAdditivecomplication:dispersants,thickeners,etc.Usedinarchitecture.WaterbornecoatingsWater-reduc75ElectrocoatingOrganiccoatingsaredepositedonproductsfromanelectrolyticbathResinsmustcontainingchargesAdvantagesanddisadvantagesUniformfilmthicknesses,lowVOC,lesslabor-intensive;highcapitalequipmentcosts,highermaterialcosts,andmorethoroughpretreatment.Application:BottomcoatingforCars;metalproducts.ElectrocoatingOrganiccoatings76PowderCoatingsResintypeThermoplastic&ThermosettingFilmformationonpreheatedproductsCoatingMethodsFluidized-bedpowdercoating.Electrostaticfluidized-bedpowdercoatingElectrostatic-spraypowdercoatingAdvantages&disadvantagesLowVOC;thicknessupto500μm;lowenergycost.ExplosionRisk;cannotbeusedinthermosensitiveproducts.PowderCoatingsResintype77SummaryTraditionalcoatingshavefourbasicingredients.Environment-friendlycoatingshavebrightfuture.Coatingindustriesarereallytechnology-intensive.SummaryTraditionalcoatingsha78ADHESIVESADHESIVES79粘接是用粘合劑將被粘物表面連接在一起的過(guò)程。2surfacescanonlybejoinedwiththeestablishmentofbondsbetweenthem.Theexactnatureofthebonddependsontheadhesiveandthesurfacetobebonded.Itisimportantwhenjoiningmaterialswithtrue

adhesivesthatthesurfacestobecompletely

clean.Evenathincoatingofgreaseorsimilarmaterial

mayreduceconsiderablytheeffectivesurface

tensionofthesurface,impairingthebond.INTRODUCTION粘接是用粘合劑將被粘物表面連接在一起的過(guò)程。2surfa80TYPESOFADHESIVECanbedividedinto3types:a)Naturaladhesives

-canbemadefromanimal,vegetableormineralsources

b)Syntheticresinbasedadhesives

i)Thermosettingadhesives

ii)Thermoplasticsyntheticadhesivesc)inorganicadhesivesTYPESOFADHESIVECanbedivide81COMPONENTSOFADHESIVE(1)粘合物質(zhì)(2)溶劑(3)增粘劑(4)消泡劑(5)增塑劑(6)填料(7)防腐劑(8)稀釋劑COMPONENTSOFADHESIVE(1)粘合物質(zhì)82NaturalAdhesivesANIMALGLUEShavebeenusedforcenturiesincarpentryandjoineryObtainedfromtheskin/bonesofcattleandsheepAnimalgluesusuallysoldinpowderandmeltedin

warmwatertogiveasolutionofsuitableviscosity.Coolingoftheliquidafterapplicationresultsinrapidgelling,producingsomestrengthanddryingfinallyproducesatoughandrigidproduct.Removalofthewaterfromglueduringcuringis

essential;thewoodassistinthisprocess,dueto

absorption.NaturalAdhesivesANIMALGLUES83

Gluedjointsinwoodshouldbeasstrongas

thewood.Dampconditionwillreducestrengthofglue.Animalglueisnotsuitableforexternaluse

unlessadequatelyprotectedfrommoisture.Thegluewillhardengraduallyinthepotbut

canbesoftenedbyreheatingwithwater.Ifafailureoccursinsuchitemsitiseasyto

carryoutrepairsbysofteningthegluewith

water.Gluedjointsinwoodshouldb84AnimalGluesAnimalGlues85CASEINGLUESItisderivedasaprecipitatefromskimmed

milkbytheactionofacids.Gluesareobtainedinpowderformthatalso

containalkalinesolvent,necessarytodissolve

theglueonadditionofwater.Mixingiscarriedoutincoldandsettingis

partlybyevaporationorabsorptionofwater

andpartlybyanaturalgelationprocess.ItsadhesiontoporousmaterialisgoodItsmoistureresistanceissuperiorthananimal

glueCASEINGLUES86CaseinGlue–ADryGlueDerivedFromMilkCaseinGlue–ADryGlueDeriv87VEGETABLEGLUEMadefromstarches(淀粉)ordextrin(糊精)lowcostlimitedstrengthandlimitedmoisture

resistanceGumArabicisawatersolublevegetable

adhesiveoftenusedonstampsandgummed

paperenvelopes.VEGETABLEGLUE88CellulosePowderATypeofVegetableAdhesiveCellulosePowderATypeofVeg89WheatPasteATypeofVegetableAdhesiveWheatPasteATypeofVegetabl90THERMOSETTINGADHESIVESUREAFORMALDEHYDEOneofthecommonestadhesivesinjoineryforgeneralpurpos