熱分析技術(shù)分析課件

1、熱分析技術(shù) 簡介(DSC, TGA & DMA)PerkinElmer Thermal Specialist 康瑜容 Tiffany KangTiffany.KangDifferential Scanning Calorimetry (DSC) Thermogravimetric Analysis (TGA) Thermomechanical Analysis (TMA)Dynamic Mechanical Analysis (DMA)常用的熱分析方法P.2 常用的熱分析方法 DSC Heat flow vs. Temp Tm, Tc, Tg DH, curing time, curing d

2、egree Reaction rate, kineticsTGAWeight Loss vs. Temp - Decomposition temperature %Wt percentage Oxidative timeTMADimensional Change vs. Temp CTE (a1, a2) Tg Softening point DMAViscoelastic property vs. Temp Storage/Loss/Complex Modulus (E, E”, E*) tan d Viscosity and master curveP.3 高分子材料結(jié)構(gòu)Type of P

3、olymer Chain StructureType Structure ExampleLinearBranched short chainLong chain branchingLadderPoly(vinyl chloride), PolystyrenePolypropylenePolypropylenePoly(imidazol pyrrolones)P.4 高分子材料結(jié)構(gòu)Type of Polymer Chain Structure (Continued)Type Structure ExampleStarNetworkInterpenetrating network (IPN)Phe

4、nol-formaldehyde resinsTwo crosslinked polymers not bonded to each otherCrosslinked epoxy with vinyl polymerP.5 高分子材料的分類PolystryenePolycarbonatePolyurethanesPolysulfoneAmorphousLOW/MEDIUMNylonPETAcetalHIGHPPSPPHDPECrystallineThermoplastics(No chemical change on heating)EpoxiesPolyimidesPolyestersPhe

5、nolicsUncuredRubberSiliconesNeopreneEpoxyCuredThermosets(Chemical change on heating)PolymersP.6 Amorphous vs. Crystalline?Amorphous ThermoplasticCrystalline PolymerP.7 Semi-Crystalline PolymerSemi-Crystalline PolymerSemi-crystalline polymers contain both amorphous AND crystalline phasesProperties do

6、minated by both Tg and TmSemi-crystalline polymers can exhibit additional crystallization during heatingP.8 Thermosetting PolymerP.9 Schematic Results in Thermal AnalysisQuality of sample process DSC(Ex) TGA TMA DMA CrystallineSemi-crystalline-Amorphous-Semi-crystalline-General-Liquid-Unspecific-Sol

7、id MeltingRecrystallizationSublimationSolid-solid transitionGlass transitionSoftening without TgPost-crosslinkingDecompositionLigand releaseEvaporationChemical reactionsDetermination of %P.10 DSC TechniqueDifferential Scanning CalorimetryQuestion?PE分成HDPE, LLDPE及LDPE - 結(jié)構(gòu)有何不同? - 性質(zhì)有何差異? - 結(jié)構(gòu)和性質(zhì)有何關(guān)聯(lián)性

8、?結(jié)晶的過程為何?加工條件對結(jié)晶有何影響?結(jié)晶度對透明度的影響?添加劑的影響?DSC可解決哪些問題?P.12 What is DSC ?示差掃瞄熱卡量計( Differential Scanning Calorimeter ) : 將樣品置於特定氣氛之下改變其溫度環(huán)境或維持在一固定溫度之中去觀察樣品其能量變化，當樣品發(fā)生熔融、蒸發(fā)、結(jié)晶、相轉(zhuǎn)變等物理現(xiàn)象，或化學變化時，圖譜中將會出現(xiàn)吸熱或放熱帶，進而可推測樣品之性質(zhì)。P.13 Thermal Analysis applications - DSCPrinciple: Heat flow change vs. temperatureMeasur

9、es: Phase transition (Tg, Tm, Tc) and heat Curing reaction and other chemical reactionsDiamond DSCP.14 Polymer TransitionsHeatFlowTemperatureTgStressReliefOrderingProcessCold CrystallizationCuringTmDHDegradationStart upTransientP.15 DSC Thermal Curve of PET吸 熱放 熱P.16 DSC for curing studiesDetection

10、of TgOnset of cureMaximum rate of cure (peak maximum)End of cureHeat of cureP.17 DSC熱示差掃描分析儀之應(yīng)用相變化點Phase Transition熔融熱H玻璃轉(zhuǎn)移溫度Tg反應(yīng)熱H熔點Melting point活化能Ea冷結(jié)晶溫度Crystal Temperature氧化導引時間O.I.T.降溫結(jié)晶溫度Cold Crystal Temperature反應(yīng)動力學Dynamic結(jié)晶度Crystallinity交連Curing結(jié)晶熱Crystal Energy純度Purity結(jié)晶半週期Crystal Period比熱C

11、pP.18 DSC的設(shè)計方式熱流式 Heat Flux DSC熱補償式 Power Compensation DSC量測DT 由DH = kDT計算DH 爐體較大直接量測DH 不需複雜數(shù)學運算 爐體較小P.19 TGA TechniqueThermogravimetric AnalyzerThermal Analysis applications - TGAPyris 1 TGAPrinciple: Weight change vs. temperatureMeasures: Compositions and wt% Thermal stability and decomposition te

12、mp.P.21 TGA Design Concept懸吊式水平式上置式P.22 TGA Thermal CurvesP.23 主要元件 Temperature control device - Furnace, Thermocouple Weight measurement device -Null BalanceDetectorTare WeightSampleTorque MotorTGA 的設(shè)計原理P.24 TGA熱重分析儀水份含量溶劑含量塑化劑含量高分子添加物含量裂解溫度灰份含量無機添加物含量氧化導引時間測量TGA-FTIR/TGA-MS熱穩(wěn)定測量不穩(wěn)定材質(zhì)測試異味材質(zhì)測試添加物種類測

13、試TGA-GC/MS未知物種類判斷混合溶劑判斷P.25 TGA for compositional analysisMolding compound contains epoxy and fillerEpoxy can be burned off and residue is inert reinforced fillerTGA provides accurate and reproducible compositional data on molding compoundP.26 Pyris 1 TGA Features:Most sensitive balance in the world

14、 with 10-7 g sensitivityIsothermal and isolated balance chamber for better stabilityIsolation convection of balance and sample purge gas to have best sensitivity and stabilityIon discharge component for keeping from electrostatic disturbanceVariety of sample pans for sample decomposition analysisP.2

15、7 TMA/DMA TechniqueMechanical AnalyzerThermal Analysis applications DMA/TMADMA 8000Principle: Viscoelastic properties vs. temperature (DMA) Dimensional change vs. temperature (TMA)Measures: Glass transition point Storage, Loss modulus and tan delta Coefficient of thermal expansion (CTE)P.29 What is

16、DMA ? DMA (Dynamic Mechanical Analyzer) 動態(tài)黏彈機械分析儀 將樣品置於特定環(huán)境下，偵測樣品在溫度、力量、或頻率改變下，其機械性質(zhì)變化的情形，進而判定材料的特性。P.30 材料的黏彈性質(zhì)E Storage Modulus 儲存模數(shù) 彈性性質(zhì)E” Loss Modulus 損失模數(shù) 黏性性質(zhì)tan d = E” / EE”EP.31 黏彈機械性質(zhì) ex. 模數(shù)(Modulus), 黏度(Viscosity), 阻尼相(tan d) 微小的相變化 ex. b,g- transition, Tg以DSC/TMA測量不易者 活化能(Activation Energ

17、y)計算預測材料使用壽命 ex. Creep Recovery, Time-temp. superposition 模擬製程中材料及環(huán)境變化 ex. Curing process, controlled humidity, Solvent Immersion 什麼時候您需要 DMA P.32 黏性彈性otimeotimeotime = 0 = 90oootimeo kDMA即為利用Sine Wave震盪方式, 測量回應(yīng)的分析儀材料的黏彈性質(zhì)P.33 Idealized DMA ScanE/PaTemperature /KTm - melting (1)Rubbery Plateau (2)Ta

18、 or TgTb (6)(5)(4)(3)(2)(1) localbendsidegraduallargechainmotionsandgroupsmainscaleslippagestretchchainchainTg (6)Rubbery plateau is related to Me between crosslinks or entanglements.For thermosets, no Tm occurs.Beta transitions are oftenrelated to the toughness.Tg is related to Molecular massup to

19、a limiting value.For purely crystalline materials, no Tg occurs.In semicrystalline polymers,a crystal-crystal slip, Ta* occurs.Tll in some amorphouspolymers(5)(4)(3)P.34 Frequency effects things tooTransitions shiftBehavior changesFrequencyEMorefluidMoreelasticP.35 So frequency can act like temperat

20、ureFrequencyETemperatureEP.36 DMA 連結(jié).材料結(jié)構(gòu)特性製程加工特性成品特性Molecular weightMW DistributionChain BranchingCross linkingEntanglementsPhasesCrystallinityFree VolumeLocalized motionRelaxation MechanismsStressStrainTemperatureHeat HistoryFrequencyPressureHeat setMaterialBehaviorDimensional StabilityImpact prop

21、ertiesLong term behaviorEnvironmental resistanceTemperature performanceAdhesionTackPeelP.37 DMA 是如何運作的?Storage ModulusLoss ModulusStatic ForceDynamic ForceFrequencyfAmplitudeKPositionHold SampledPhaseThermocoupleTotal Force LVDTFurnace Options from -190 to 600 CForce motorFixturesP.38 多樣化的夾具選擇Option

22、s:Single CantileverDual Cantilever3 Point BendingTensionCompressionShearQuartz ShearMaterial PocketP.39 Exclusive Material Pockets ApplicationsPowders like drugs, excipients, foods, natural products, etc.Gels Uncured adhesivesCoatingsSamples that cant support their own weightPocket openSample in Poc

23、ketPocket closed & sealedP.40 DMA mode for mechanical properties changeThis plot shows DMA results (E and tan delta) for cured substrateDMA gives the most sensitive measure of TgDMA results show that substrate is incompletely cured as 2 split peak was found in tan delta around TgP.41 DMA most sensit

24、ive indicator of cureThis plot shows DMA results on completely cured and slightly under-cured PCBsUnder-cured PCB exhibits a slight increase in E above Tg making the board unacceptableP.42 TMA mode for dimensional changePlot shows results on TMA expansivity of substrate1st heat shows that the board contains built in stresses as a result of processing Stresses are released at Tg2nd heat shows classic TMA Tg free of stress relief effectsP.43 更多熱分析的應(yīng)用P.44 高分子熱性質(zhì)量測高分子的 Tg 分析 - 加熱歷史的差異P.46 結(jié)晶測試 - 恆溫結(jié)晶P.47 交連測試 - 升溫交連