DifferentialScanningCalorimetry(DSC)Theory&Applications1DifferentialScanningCalorime整體概述THEFIRSTPARTOFTHEOVERALLOVERVIEW,PLEASESUMMARIZETHECONTENT第一部分2整體概述第一部分2差示掃描量熱儀(DSC)DSC測量樣品吸熱和放熱與溫度或時間的關系吸熱熱流入樣品，即樣品吸收外界熱量，為負值。放熱熱流出樣品，即樣品對外界放出熱量，為正值。國際標準ISO11357-1:：

DSC就是測量在程序控制溫度下，輸入到試樣和參比物之間的功率差（dH/dt）與溫度(T)的關系的一種技術。該熱流差能反映樣品隨溫度或時間變化所發生的焓變：樣品吸收能量時，焓變為吸熱；當樣品釋放能量時，焓變為放熱。3差示掃描量熱儀(DSC)DSC測量樣品吸熱和放熱與溫度或時EndothermicHeatFlowHeatflowsintothesampleasaresultofeitherHeatcapacity(heating)GlassTransition(Tg)MeltingEvaporationOtherendothermicprocessesEndothermic4EndothermicHeatFlowHeatflowExothermicHeatFlowHeatflowsoutofthesampleasaresultofeitherHeatcapacity(cooling)CrystallizationCuringOxidationOtherexothermicprocessesExothermic5ExothermicHeatFlowHeatflowsDSC與DTA測定原理的不同DSC是在控制溫度變化情況下，以溫度（或時間）為橫坐標，以樣品與參比物間溫差為零所需供給的熱量為縱坐標所得的掃描曲線。DTA是測量T-T的關系，而DSC是保持T=0，測定H-T的關系。兩者最大的差別是DTA只能定性或半定量，而DSC的結果可用于定量分析。6DSC與DTA測定原理的不同DSC是在控制溫度變化情況下，以DSC:WhatDSCCanTellYouGlassTransitions（玻璃化轉變，Tg）MeltingandBoilingPoints（熔點和沸點）Crystallizationtimeandtemperature（結晶時間和溫度）PercentCrystallinity（結晶度）Polymorphism（多種形態）HeatsofFusionandReactions（熔化和反應熱）SpecificHeat（比熱）Oxidative/ThermalStability（氧化/熱穩定性）RateandDegreeofCure（固化速率和程度）ReactionKinetics（反應動力學）Purity（純度）7DSC:WhatDSCCanTellYouGlasDSC:典型DSC轉變溫度熱流->放熱玻璃化轉變結晶熔化交聯(固化)氧化或分解8DSC:典型DSC轉變溫度熱流->放熱玻璃化轉變結熱流型(HeatFlux)在給予樣品和參比品相同的功率下，測定樣品和參比品兩端的溫差T，然后根據熱流方程，將T（溫差）換算成Q（熱量差）作為信號的輸出。功率補償型(PowerCompensation)在樣品和參比品始終保持相同溫度的條件下，測定為滿足此條件樣品和參比品兩端所需的能量差，并直接作為信號Q（熱量差）輸出。調制熱流型(ModulatedHeatFlux)在傳統熱流型DSC線性變溫基礎上，疊加一個正弦震蕩溫度程序，最后效果是可隨熱容變化同時測量熱流量，利用傅立葉變換將熱流量即時分解成熱容成分動力學成分。1、DSC的基本原理9熱流型(HeatFlux)1、DSC的基本原理9FurnaceThermocouplesSampleReferencePlatinumAlloyPRTSensorPlatinumResistanceHeaterHeatSink熱流型DSC功率補償型DSCSample傳統量熱儀內部示意圖精確的溫度控制和測量更快的響應時間和冷卻速度高分辨率基線穩定高靈敏度10FurnaceThermocouplesSampleRefe

熱流DSC爐子剖面圖DynamicSampleChamberReferencePanSamplePanLidGasPurgeInletChromelDiscHeatingBlockChromelDiscAlumelWireChromelWireThermocoupleJunctionThermoelectricDisc(Constantan)11熱流DSC爐子剖面圖DynamicSampleC熱流式DSC-工作原理RsRrTfsTrsTsTr12熱流式DSC-工作原理RsRrTfsTrsTsTr12熱流式DSC-工作原理假設:

1,傳感器絕對對稱，Tfs=Tfr，Rs=Rr=R 2,樣品和參比端的熱容相等Cpr-Cps 3,樣品和參比的加熱速率永遠相同 4,樣品盤及參比盤的質量（熱容）相等 5,樣品盤、參比盤與傳感器之間沒有熱阻或熱阻相等

13熱流式DSC-工作原理假設: 1,傳感器絕對對稱，THeatFluxDSC:TheoreticalDTMeasurementTrTsDTToTpTr=ReferenceTemperatureTs=SampleTemperatureTo=OnsetofMeltTp=PeakofMeltTheoretically:To=TpTimeTemperature14HeatFluxDSC:TheoreticalDTActualHeatFluxDataSlopeduetothermallagDT15ActualHeatFluxDataSlopedueViolationsofAssumptionsPanandcalorimeterheatcapacitiesareignoredSampleandreferenceheatcapacitiesareassumedtobethesameandtoheatatthesamerate.Ingeneralthesampleandreferencecalorimeterheatcapacitiesdonotmatchcontributingtonon-zeroemptyDSCheatflowratebaseline.DuringtransitionsandMDSC?experimentsthesampleandreferenceheatingratesdifferandthemeasuredheatflowrateisincorrectbecausethesampleandreferencesensorandpanheatcapacitiesstoreorreleaseheatatdifferentrates.16ViolationsofAssumptionsPanaExpandedPrincipleofOperation

Q=Ts-Tr+A+B+C R

ThermalResistanceImbalance

ThermalCapacitanceImbalance

HeatingRateImbalanceTfsTsRsTfrTrRrCsCrNotBeingMeasuredw/ConventionalDSC17ExpandedPrincipleofOperatiQ-SeriesDSCSchematicSample&ReferencePlatformsTzero?Thermocouple18Q-SeriesDSCSchematicSample&Q-SeriesHeatFlowMeasurementTrTsRsCsCrRrToTfQ-SeriesDSCTheTzerothermocoupleprovidesan

objectivereferencepointsothatthose

factorspreviouslyassumedcanbedirectly

measured.19Q-SeriesHeatFlowMeasurementTzero?HeatFlowMeasurementHeatFlowRateEquationsHeatFlowSensorModelThesampleandreferencecalorimeterthermalresistancesandheatcapacitiesobtainedfromTzerocalibrationareusedintheheatflowratemeasurements.DifferentialTemperatures20Tzero?HeatFlowMeasurementHeTzero?HeatFlowTermContributionsPrincipalheatflowprovidesmainheatflowsignalThermalresistanceandheatcapacityimbalancetermsimprovebaselineHeatingratedifferencetermimprovesresolutionandMDSCperformance21Tzero?HeatFlowTermContribuTo技術的四相

熱流方程基本熱流熱阻不平衡熱容不平衡加熱速率不平衡標準DSC的單項熱流方程To技術提供的額外項22To技術的四相熱流方程基本熱流熱阻不平衡熱容不平衡加熱速T0及高級T0技術對DSC測量的改進：T0不需假設（Q200/Q100DSC):

1,傳感器絕對對稱，Tfs=Tfr，Rs=Rr=R 2,樣品和參比端的熱容相等Cpr-Cps 3,樣品和參比的加熱速率永遠相同高級To不需假設(Q2000/Q1000DSC)：

4,樣品盤及參比盤的質量（熱容）性等 5,樣品盤、參比比盤與傳感器之間沒有熱阻或熱阻相等23T0及高級T0技術對DSC測量的改進：T0不需假設（Q200BaselineBowImprovement24BaselineBowImprovement24SuperiorResolutiononaPharmaceuticalSampleAnalysis25SuperiorResolutiononaPharmResolutionImprovement26ResolutionImprovement26AdvancedTzero?Results27AdvancedTzero?Results27MDSC?測量什么?

MDSC將熱流分解成與變化的升溫速率相關和不相關的兩部分MDSC將變化的升溫速率疊加在線性的升溫速率上是為了測量與變化的升溫速率相關的熱流

一般來講,只有熱容與熔融的變化與變化的升溫速率相關.MDSC的可逆和不可逆信號

絕不能

樣品可逆和不可逆性質的測量

28MDSC?測量什么?MDSC將熱流分解成與變化的升溫速MDSC?

原理MDSC?

同時采用兩種升溫速率平均升溫速率提供平均升溫速率，它相當與普通標準DSC@在同樣升溫速率下的信號調制升溫速率目的是為了在得到熱流信號的同時得到熱容的信號29MDSC?原理MDSC?同時采用兩種升溫速率29StandardDSCMeasurestheSumofHeatFlowdH/dt=Cp(dT/dt)+?(T,t)30StandardDSCMeasurestheSumStandardDSCMeasurestheSumofHeatFlowWhichArisesfromMultipleSourcesdH/dt=Cp(dT/dt)+?(T,t)31StandardDSCMeasurestheSumIdealSeparationofHeatFlowdH/dt=?(T,t)dH/dt=Cp(dT/dt)32IdealSeparationofHeatFlowd平均&調制溫度信號調制溫度平均溫度Modulate+/-0.42°Cevery40secondsRamp4.00°C/minto290.00°C525456586062ModulatedTemperature(°C)525456586062Temperature(°C)13.013.514.014.515.0Time(min)33平均&調制溫度信號調制溫度平均溫度Modulate+/平均&調制升溫速率周期平均升溫速率調制升溫速率0246810Deriv.ModulatedTemperature(°C/min)0246810Deriv.Temperature(°C/min)13.013.514.014.515.0Time(min)34平均&調制升溫速率周期平均升溫速率調制升溫速率02468MDSCRawDataSignals…ModulatedHeatFlow

andModulatedTemperature(HeatingRate)Signalshavean“Average”andan“Amplitude”35MDSCRawDataSignals…Modulate調制DSC總熱流：調制熱流的傅立葉轉換36調制DSC總熱流：調制熱流的傅立葉轉換36CalculationofReversingCpModulatedHeatingRateModulatedHeatFlowReversingCp37CalculationofReversingCpMod調制DSC?

不同成分的概念MDSC?DataSignals可逆熱流ReversingTransitions熱容HeatCapacity玻璃化轉變GlassTransition大部分的熔融MostMelting總熱流=可逆熱流+不可逆熱流38調制DSC?不同成分的概念MDSC?DataSignaMDSC?DataSignals總熱流=可逆熱流+

不可逆熱流不可逆轉變熱焓松弛EnthalpicRecovery揮發Evaporation結晶Crystallization熱固化ThermosetCure蛋白質變性ProteinDenaturation淀粉糊化StarchGelatinization分解Decomposition部分熔融SomeMelting調制DSC?不同成分的概念39MDSC?DataSignals總熱流=MDSC?無定形PETNonreversingReversingTotal-0.4-0.20.0NonrevHeatFlow(W/g)-0.4-0.20.00.20.4RevHeatFlow(W/g)-0.4-0.20.00.2HeatFlow(W/g)050100150200250300Temperature(°C)ExoUp40MDSC?無定形PETNonreversingRever何時&為什么運行MDSC?？我需要比熱信息嗎？轉變是一個比熱相關的現象嗎?有被其他效應掩蓋的現象嗎？存在對于標準DSC來講很微弱或很寬的轉變嗎？是否需要更高的靈敏度或分辨率嗎？比熱會在恒溫條件下隨著時間而變化嗎（比如恒溫固化）？41何時&為什么運行MDSC?？我需要比熱信息嗎？41何時&為什么運行MDSC?？對于熔融和結晶–如果熔融過程看起來正常(單個吸熱峰)并且在加熱時無明顯的結晶

，就不必采用MDSC然而,如果熔融過程很復雜,或很難確定樣品是否在加熱時

存在結晶,采用MDSC如果想得到比熱(Cp)–運行MDSC通過常規DSC得到比熱(Q1000由于直接比熱的測量是個例外)采用較高的升溫速率,>10°C/min需要三個實驗基線參考樣(藍寶石)樣品42何時&為什么運行MDSC?？對于熔融和結晶–如果想得普通DSC的局限性不可能在單個DSC的實驗中同時提高靈敏度和分辨率升溫速率快，靈敏度提高，分辨率下降升溫速率慢，分辨率提高，靈敏度下降MDSC?可以解決該問題是因為他有兩個升溫速率基線彎曲度和漂移限制了DSC檢測弱轉變的靈敏度MDSC?消除了基線彎曲度和漂移是在于熱容信號的取得是采用如下等式:

K

x調制升溫速率振幅調制熱流振幅Cp=平均升溫速率

xCp可逆熱流=43普通DSC的局限性不可能在單個DSC的實驗中同時提高靈敏度圖譜很難解釋因為DSC測量的是總熱流MDSC?不僅僅提供總熱流，而且包括熱容的信號和動力學組分4.

很難通過普通DSC準確測量聚合物的結晶度.

準確測量結晶度，需要:確定真正的熱容基線定量測量在加熱過程中有多少結晶在繼續發展44圖譜很難解釋4.很難通過普通DSC準確測量聚合物的結晶度.Application

HeatCapacity

GlassTransitionMeltingandCrystallizationThermoplasticsThermosets

AdditionalApplicationsExamples45Application45如果我們要用DSC測量比熱怎么辦？當f(x)=0時（沒有動力學相關現象時）。樣品熱流可簡寫為：Q=Cp··m

。通過兩次不同加熱速率對樣品進行測試即可得到：K為儀器校正系數1、Cp的測量46如果我們要用DSC測量比熱怎么辦？K為儀器校正系數1、Cp的傳統DSC測量樣品比熱Cp首先需要確定K值。可以通過已知比熱的標準材料（如藍寶石）來確定。

基線的重現性對Cp測量影響必須考慮。為了得到更好的Cp數據首先要測試空白基線，然后對每次樣品測試結果進行基線扣除。

不要忘記我們在進行熱流計算時的假設條件。這是測量誤差的來源之一。K為儀器校正系數47傳統DSC測量樣品比熱Cp首先需要確定K值。K為儀器校正系數傳統

DSC測量比熱的方法

:48傳統DSC測量比熱的方法:48DirectCpMeasurementonQ2000/Q1000UnlikeanyotherDSC,theheatflowsignaloftheQ2000/Q1000isanabsolutesignal:BaselineisflatAbsolutezeroheatflowvalueestablishedaspartofmethodByknowingabsolutevaluesoftheheatflowandtheheatingrate,heatcapacityiscalculatedinrealtimeandstoredindatafileAccuracyandprecisionisgenerally±1-2%withjustsinglerunmeasurements49DirectCpMeasurementonQ2000HeatFlowandHeatCapacityfromtheSameExperimentPolypropylene50HeatFlowandHeatCapacityfrItIsOftenDifficulttoIdentifytheTrueBaseline

UsingOnlyHeatFlow51ItIsOftenDifficulttoIdentHeatCapacitySignalsAreNormalizedforHeatingRateandPermitComparisonofExperimentsatDifferentHeatingRatesRemember,DSCandMDSCCpsignalsarereallyApparentCpsignals;

crystallizationandmeltingarelatentheats,notCp52HeatCapacitySignalsAreNormEffectofSideChainsonCpPolymerSideChainCp(J/g/°C)PE-H2.763PP-CH2.752PS-Ph2.139Asthestericbulkofthesidechainincreases,molecularmobilitydecreasesresultinginlowerspecificheat.B.Wunderlich,ATHASCpDataBank,1985.53EffectofSideChainsonCpPolEffectofPolymerBackboneonCp#ofMethylenesCp(J/g/°C)10.622620.691830.708840.759780.7736OCH2n)O([]Asthenumberofmethylenesincrease,mobilityisincreasedinthepolymer,resultinginhigherheatcapacity.B.Wunderlich,ATHASCpDataBank,1985.Polyoxyalkenes@-153°C54EffectofPolymerBackboneonEffectofCopolymerCompositiononCpCompositionCopolymerCp(%PP)(Type)(J/°C/mol)6.0block15.127.5random16.3915.5random18.54AsPPconcentrationisincreased,thenumberofmethylenesincreases,resultinginariseinspecificheatcapacity.Also,withrandomnesscomesentropy（熵）,increaseinmobility,andincreaseinspecificheatcapacity.B.Wunderlich,ATHASCpDataBank,1985.PE/PPCopolymer@-93°C55EffectofCopolymerCompositio2GlassTransitiondQ/dtdQ/dt溫度溫度TgTg1/2從DSC曲線上確定Tg的方法562GlassTransitiondQ/dtdQ/dtPMMA1stHeatPMMA-Aged1stHeat@10°C/min6.87mgEnthalpicRecoveryPeak122.42°C(H)-0.6-0.4-0.20.0HeatFlow(W/g)406080100120140160Temperature(°C)

ExoUpUniversalV4.2DTAInstruments57PMMA1stHeatPMMA-Aged1stHePMMA2ndHeatPMMA-Aged2ndHeat@10°C/min6.87mg121.52°C(H)-0.6-0.4-0.20.0HeatFlow(W/g)406080100120140160Temperature(°C)

ExoUp58PMMA2ndHeatPMMA-Aged2ndHeComparisonPMMA1stHeat&2ndHeatPMMA-Aged1stHeat@10°C/min6.87mgEnthalpicRecoveryPeakPMMA-Aged2ndHeat@10°C/min6.87mg-0.6-0.4-0.20.0HeatFlow(W/g)406080100120140160Temperature(°C)ExoUpUniversalV4.2DTAInstruments59ComparisonPMMA1stHeat&2ndEnthalpyRelaxation/RecoveryatTgEnthalpyrelaxation,oraging,istheprocessofamorphousmaterialapproachingequilibrium(neverreached).EnergyisreleasedasafunctionoftimeandtemperatureEnthalpyrecoveryistheendothermictransitionseenattheendofaglasstransitioninDSCexperiments.ItistherecoveryofenergythatwasdissipatedduringagingIntraditionalDSC,enthalpyrecoverycanappearasameltandmakemeasurementofTgdifficultSinceenthalpyrecoveryisakineticevent,itcanbeseparatedfromthechangeinheatcapacitybyMDSC60EnthalpyRelaxation/Recoverya6161PracticalSignificanceofEnthalpyRecoveryIsenthalpyrecoveryattheglasstransitionimportant?Sometimes!Iftwosamplesoffinishedproducthavesignificantlydifferentsizeenthalpyrecoverypeaks(differby0.5J/gormore),theycanbeexpectedtoshowdifferencesinsomephysicalproperties(size,hardness,impactresistance,etc.)DifferencesinthesizeoftheenthalpyrecoverypeakforrawmaterialsthatwillbeprocessedattemperaturesaboveTgarenotimportantThethermalhistoryofrawmaterialsisusuallynotcontrolledThesesamplesshouldbecomparedaftertheyareheatedtoatemperatureaboveTgwhichremovesthepreviousthermalhistory62PracticalSignificanceofEnthMDSCSeparationofEnthalpyRecoveryPeakTotalHeatFlowincludesTgandenthalpyrecoverypeakReversingHeatFlowcontainsonlyTgNonreversingHeatFlowcontainsenthalpyrecoverypeak63MDSCSeparationofEnthalpyReTg在哪里?藥片,44%RH3.08mgMDSC?1/60/5Tg在哪里?64Tg在哪里?藥片,44%RH3.08mgTg在這里!Tg在這里!65Tg在這里!Tg在這里!65復雜樣品QuenchedXenoy14.79mg10°C/min復雜樣品66復雜樣品QuenchedXenoy14.79mg1MDSC?

有助于圖譜解釋MDSC?

有助于圖譜解釋67MDSC?有助于圖譜解釋MDSC?有助于圖譜解釋67無定形態PET/PC的DSC，PC的Tg在哪里?68無定形態PET/PC的DSC，PC的Tg在哪里?68MDSC在聚合物共混物中顯示兩個Tg

MDSC?.318/40/369MDSC在聚合物共混物中顯示兩個TgMDSC?.31DSC@5°C/minforDrugMicrospheresPolymer70%CrystallineDrug15%AmorphousDrug15%Approx.Composition70DSC@5°C/minforDrugMicrospMDSC?@2°C/minforDrugMicrospheres71MDSC?@2°C/minforDrugMicro聚合物合金的普通DSC淬冷PET/PC/HDPE72聚合物合金的普通DSC淬冷PET/PC/HDPE72聚合物合金的MDSC?

MeltingofPETMeltingofHDPEZoominonthisarea73聚合物合金的MDSC?MeltingofPETMelt聚合物的MDSC?TgofPETTgofPCCrystallizationofPETMeltingofHDPE74聚合物的MDSC?TgofPETTgofPCCry小甜品在冷卻過程中的玻璃化轉變

75小甜品在冷卻過程中的玻璃化轉變75InterpretingChangeinStructure

forDrugMonohydrateCpofFirstHeatCpofSecondHeatLossofcrystallinityondehydrationRecrystallizationGlassTransitionSampleanalyzedinpinholepan76InterpretingChangeinStructu3、ThermosetMaterialsA“thermoset”isacross-linkedpolymerformedbyanirreversibleexothermicchemicalreactionAcommonexampleisa2partepoxyadhesiveWithaDSCwecanlookatthecuringofthesematerials,andtheTgoffullorpartiallycuredsamples773、ThermosetMaterialsA“thermoThermosettingPolymersThermosettingpolymersreact(cross-link)irreversibly.A+Bwillgiveoutheat(exothermic)whentheycross-link(cure).Aftercoolingandreheating,

CwillhaveonlyaglasstransitionTg.A+BCGLUEThermosetMaterials78ThermosettingPolymersThermoseCuringofaThermosettingMaterialbyDSC116.07°C76.30°C195.0J/g20MinEpoxyCuredinDSC15.15mg@10°C/min-6-4-202468HeatFlow(mW)050100150200Temperature(°C)DSCExoUpUniversalV4.3ATAInstruments79CuringofaThermosettingMateEffectofHeatingRateonThermosetCuring80EffectofHeatingRateonTher殘余固化隱藏玻璃化轉變10.85mgEpoxyheating@3°/min,afterisothermalcureat100°C81殘余固化隱藏玻璃化轉變10.85mgEpoxyheatAdvantageofMDSCforPostCureScanSample:EpoxySize:10.85mgHeatingExperimentat3C/minAfter160minIsothermalCureat100CNoteOnsetofDecompositionBeforeCompleteCureNoteInabilitytoMeasureTg82AdvantageofMDSCforPostCur1、掃描速度的影響靈敏度隨掃描速度提高而增加分辨率隨掃描速度提高而降低技巧：增加樣品量得到所要求的靈敏度低掃描速度得到所要求的分辨率DSC測試過程中的影響因素831、掃描速度的影響DSC測試過程中的影響因素83掃描速度的影響84掃描速度的影響84大適用于測試低程度的轉變、非均勻試樣峰寬、溫度準確度、分辨率低。要求dT/dt小。小峰尖，分辨率好，對零級反應的轉變溫度要求平衡值，允許有大的dT/dt，

2、樣品尺寸3、氣氛—不能與試樣反應，動態優于靜態。高傳熱系數氣體（如H2、He）分辨率高；

低傳熱系數氣體（如真空）靈敏度高。樣品皿的封壓：底面平整、樣品不外露合適的樣品量：靈敏度與分辨率的折中85大適用于測試低程度的轉樣品的粒度與形狀對曲線的影響AgNO3的DSC曲線

a.原塊狀樣品b.稍研磨樣品c.先熔化冷卻后再測160165.5210bc吸熱放熱aT拉伸過PET的DSC曲線未拉伸PET的DSC曲線86樣品的粒度與形狀對曲線的影響AgNO3的DSC曲線16014、選擇合適的樣品盤SamplePan:Crimpedvs.HermeticallySealedCrimpedpansarelighter(?23mg)andprovidebettersensitivityandresolutionHermeticaluminumpansareheavier(?55mg)butcanbesealedtopreventlossofvolatilesHermeticstainlesssteelpans(?250mg)permituseoflargesamples(100mg)andhighertemperatures/pressures(2000psig=1.4MPa)Careshouldbetakentokeepthebottomofallpansflattoimproveheattransfer/resolution874、選擇合適的樣品盤SamplePan:CrimpedSamplePans Typeofpandependson:SampleformVolatilizationTemperaturerangeUselightest,flattestpanpossibleAlwaysusereferencepanofthesametypeassamplepan88SamplePans TypeofpandependHermeticPans(Sealed)HermeticPansareavailablein:Aluminum:<600°C;<3atm(300kPagage)AlodinedAluminum:<600°C;<3atm(300kPagage)(Foraqueoussamples)Gold:<725°C;<6atm(600kPagage)SpecializedSealedPansHighVolume:100μL;<250°C;600psig(4.1MPa)HighPressure:35μL;<300°C;1450psig(10MPa)Note:3atmisapproximately44psig89HermeticPans(Sealed)HermeticFactorsAffectingSensitivity/ResolutionThermocoupleOutputMagnitudeofDTSignal/NoiseBaselineQualityTimeConstantofTransducerPanContactResistanceSensitivityResolutionTheflatnessofthebottomoftheDSCpanincriticaltooptimizingresolution90FactorsAffectingSensitivity/ItDoesMatterWhatPanYouUseMonohydratePharmaceuticalsample91ItDoesMatterWhatPanYouUsHowdowekeepDSCcellsclean?DONOTDECOMPOSESAMPLESINTHEDSCCELL!!!RunTGAtodeterminethedecompositiontemperatureStaybelowthattemperature!MakesurebottomofpansstaycleanUselidsUsehermeticpansifnecessary92HowdowekeepDSCcellsclean提問與解答環節Questionsandanswers93提問與解答環節93結束語

感謝參與本課程，也感激大家對我們工作的支持與積極的參與。課程后會發放課程滿意度評估表，如果對我們課程或者工作有什么建議和意見，也請寫在上邊94結束語

94謝謝聆聽THANKYOUFORLISTENING演講者：XX時間：202X.XX.XX95謝謝聆聽95DifferentialScanningCalorimetry(DSC)Theory&Applications96DifferentialScanningCalorime整體概述THEFIRSTPARTOFTHEOVERALLOVERVIEW,PLEASESUMMARIZETHECONTENT第一部分97整體概述第一部分2差示掃描量熱儀(DSC)DSC測量樣品吸熱和放熱與溫度或時間的關系吸熱熱流入樣品，即樣品吸收外界熱量，為負值。放熱熱流出樣品，即樣品對外界放出熱量，為正值。國際標準ISO11357-1:：

DSC就是測量在程序控制溫度下，輸入到試樣和參比物之間的功率差（dH/dt）與溫度(T)的關系的一種技術。該熱流差能反映樣品隨溫度或時間變化所發生的焓變：樣品吸收能量時，焓變為吸熱；當樣品釋放能量時，焓變為放熱。98差示掃描量熱儀(DSC)DSC測量樣品吸熱和放熱與溫度或時EndothermicHeatFlowHeatflowsintothesampleasaresultofeitherHeatcapacity(heating)GlassTransition(Tg)MeltingEvaporationOtherendothermicprocessesEndothermic99EndothermicHeatFlowHeatflowExothermicHeatFlowHeatflowsoutofthesampleasaresultofeitherHeatcapacity(cooling)CrystallizationCuringOxidationOtherexothermicprocessesExothermic100ExothermicHeatFlowHeatflowsDSC與DTA測定原理的不同DSC是在控制溫度變化情況下，以溫度（或時間）為橫坐標，以樣品與參比物間溫差為零所需供給的熱量為縱坐標所得的掃描曲線。DTA是測量T-T的關系，而DSC是保持T=0，測定H-T的關系。兩者最大的差別是DTA只能定性或半定量，而DSC的結果可用于定量分析。101DSC與DTA測定原理的不同DSC是在控制溫度變化情況下，以DSC:WhatDSCCanTellYouGlassTransitions（玻璃化轉變，Tg）MeltingandBoilingPoints（熔點和沸點）Crystallizationtimeandtemperature（結晶時間和溫度）PercentCrystallinity（結晶度）Polymorphism（多種形態）HeatsofFusionandReactions（熔化和反應熱）SpecificHeat（比熱）Oxidative/ThermalStability（氧化/熱穩定性）RateandDegreeofCure（固化速率和程度）ReactionKinetics（反應動力學）Purity（純度）102DSC:WhatDSCCanTellYouGlasDSC:典型DSC轉變溫度熱流->放熱玻璃化轉變結晶熔化交聯(固化)氧化或分解103DSC:典型DSC轉變溫度熱流->放熱玻璃化轉變結熱流型(HeatFlux)在給予樣品和參比品相同的功率下，測定樣品和參比品兩端的溫差T，然后根據熱流方程，將T（溫差）換算成Q（熱量差）作為信號的輸出。功率補償型(PowerCompensation)在樣品和參比品始終保持相同溫度的條件下，測定為滿足此條件樣品和參比品兩端所需的能量差，并直接作為信號Q（熱量差）輸出。調制熱流型(ModulatedHeatFlux)在傳統熱流型DSC線性變溫基礎上，疊加一個正弦震蕩溫度程序，最后效果是可隨熱容變化同時測量熱流量，利用傅立葉變換將熱流量即時分解成熱容成分動力學成分。1、DSC的基本原理104熱流型(HeatFlux)1、DSC的基本原理9FurnaceThermocouplesSampleReferencePlatinumAlloyPRTSensorPlatinumResistanceHeaterHeatSink熱流型DSC功率補償型DSCSample傳統量熱儀內部示意圖精確的溫度控制和測量更快的響應時間和冷卻速度高分辨率基線穩定高靈敏度105FurnaceThermocouplesSampleRefe

熱流DSC爐子剖面圖DynamicSampleChamberReferencePanSamplePanLidGasPurgeInletChromelDiscHeatingBlockChromelDiscAlumelWireChromelWireThermocoupleJunctionThermoelectricDisc(Constantan)106熱流DSC爐子剖面圖DynamicSampleC熱流式DSC-工作原理RsRrTfsTrsTsTr107熱流式DSC-工作原理RsRrTfsTrsTsTr12熱流式DSC-工作原理假設:

1,傳感器絕對對稱，Tfs=Tfr，Rs=Rr=R 2,樣品和參比端的熱容相等Cpr-Cps 3,樣品和參比的加熱速率永遠相同 4,樣品盤及參比盤的質量（熱容）相等 5,樣品盤、參比盤與傳感器之間沒有熱阻或熱阻相等

108熱流式DSC-工作原理假設: 1,傳感器絕對對稱，THeatFluxDSC:TheoreticalDTMeasurementTrTsDTToTpTr=ReferenceTemperatureTs=SampleTemperatureTo=OnsetofMeltTp=PeakofMeltTheoretically:To=TpTimeTemperature109HeatFluxDSC:TheoreticalDTActualHeatFluxDataSlopeduetothermallagDT110ActualHeatFluxDataSlopedueViolationsofAssumptionsPanandcalorimeterheatcapacitiesareignoredSampleandreferenceheatcapacitiesareassumedtobethesameandtoheatatthesamerate.Ingeneralthesampleandreferencecalorimeterheatcapacitiesdonotmatchcontributingtonon-zeroemptyDSCheatflowratebaseline.DuringtransitionsandMDSC?experimentsthesampleandreferenceheatingratesdifferandthemeasuredheatflowrateisincorrectbecausethesampleandreferencesensorandpanheatcapacitiesstoreorreleaseheatatdifferentrates.111ViolationsofAssumptionsPanaExpandedPrincipleofOperation

Q=Ts-Tr+A+B+C R

ThermalResistanceImbalance

ThermalCapacitanceImbalance

HeatingRateImbalanceTfsTsRsTfrTrRrCsCrNotBeingMeasuredw/ConventionalDSC112ExpandedPrincipleofOperatiQ-SeriesDSCSchematicSample&ReferencePlatformsTzero?Thermocouple113Q-SeriesDSCSchematicSample&Q-SeriesHeatFlowMeasurementTrTsRsCsCrRrToTfQ-SeriesDSCTheTzerothermocoupleprovidesan

objectivereferencepointsothatthose

factorspreviouslyassumedcanbedirectly

measured.114Q-SeriesHeatFlowMeasurementTzero?HeatFlowMeasurementHeatFlowRateEquationsHeatFlowSensorModelThesampleandreferencecalorimeterthermalresistancesandheatcapacitiesobtainedfromTzerocalibrationareusedintheheatflowratemeasurements.DifferentialTemperatures115Tzero?HeatFlowMeasurementHeTzero?HeatFlowTermContributionsPrincipalheatflowprovidesmainheatflowsignalThermalresistanceandheatcapacityimbalancetermsimprovebaselineHeatingratedifferencetermimprovesresolutionandMDSCperformance116Tzero?HeatFlowTermContribuTo技術的四相

熱流方程基本熱流熱阻不平衡熱容不平衡加熱速率不平衡標準DSC的單項熱流方程To技術提供的額外項117To技術的四相熱流方程基本熱流熱阻不平衡熱容不平衡加熱速T0及高級T0技術對DSC測量的改進：T0不需假設（Q200/Q100DSC):

1,傳感器絕對對稱，Tfs=Tfr，Rs=Rr=R 2,樣品和參比端的熱容相等Cpr-Cps 3,樣品和參比的加熱速率永遠相同高級To不需假設(Q2000/Q1000DSC)：

4,樣品盤及參比盤的質量（熱容）性等 5,樣品盤、參比比盤與傳感器之間沒有熱阻或熱阻相等118T0及高級T0技術對DSC測量的改進：T0不需假設（Q200BaselineBowImprovement119BaselineBowImprovement24SuperiorResolutiononaPharmaceuticalSampleAnalysis120SuperiorResolutiononaPharmResolutionImprovement121ResolutionImprovement26AdvancedTzero?Results122AdvancedTzero?Results27MDSC?測量什么?

MDSC將熱流分解成與變化的升溫速率相關和不相關的兩部分MDSC將變化的升溫速率疊加在線性的升溫速率上是為了測量與變化的升溫速率相關的熱流

一般來講,只有熱容與熔融的變化與變化的升溫速率相關.MDSC的可逆和不可逆信號

絕不能

樣品可逆和不可逆性質的測量

123MDSC?測量什么?MDSC將熱流分解成與變化的升溫速MDSC?

原理MDSC?

同時采用兩種升溫速率平均升溫速率提供平均升溫速率，它相當與普通標準DSC@在同樣升溫速率下的信號調制升溫速率目的是為了在得到熱流信號的同時得到熱容的信號124MDSC?原理MDSC?同時采用兩種升溫速率29StandardDSCMeasurestheSumofHeatFlowdH/dt=Cp(dT/dt)+?(T,t)125StandardDSCMeasurestheSumStandardDSCMeasurestheSumofHeatFlowWhichArisesfromMultipleSourcesdH/dt=Cp(dT/dt)+?(T,t)126StandardDSCMeasurestheSumIdealSeparationofHeatFlowdH/dt=?(T,t)dH/dt=Cp(dT/dt)127IdealSeparationofHeatFlowd平均&調制溫度信號調制溫度平均溫度Modulate+/-0.42°Cevery40secondsRamp4.00°C/minto290.00°C525456586062ModulatedTemperature(°C)525456586062Temperature(°C)13.013.514.014.515.0Time(min)128平均&調制溫度信號調制溫度平均溫度Modulate+/平均&調制升溫速率周期平均升溫速率調制升溫速率0246810Deriv.ModulatedTemperature(°C/min)0246810Deriv.Temperature(°C/min)13.013.514.014.515.0Time(min)129平均&調制升溫速率周期平均升溫速率調制升溫速率02468MDSCRawDataSignals…ModulatedHeatFlow

andModulatedTemperature(HeatingRate)Signalshavean“Average”andan“Amplitude”130MDSCRawDataSignals…Modulate調制DSC總熱流：調制熱流的傅立葉轉換131調制DSC總熱流：調制熱流的傅立葉轉換36CalculationofReversingCpModulatedHeatingRateModulatedHeatFlowReversingCp132CalculationofReversingCpMod調制DSC?

不同成分的概念MDSC?DataSignals可逆熱流ReversingTransitions熱容HeatCapacity玻璃化轉變GlassTransition大部分的熔融MostMelting總熱流=可逆熱流+不可逆熱流133調制DSC?不同成分的概念MDSC?DataSignaMDSC?DataSignals總熱流=可逆熱流+

不可逆熱流不可逆轉變熱焓松弛EnthalpicRecovery揮發Evaporation結晶Crystallization熱固化ThermosetCure蛋白質變性ProteinDenaturation淀粉糊化StarchGelatinization分解Decomposition部分熔融SomeMelting調制DSC?不同成分的概念134MDSC?DataSignals總熱流=MDSC?無定形PETNonreversingReversingTotal-0.4-0.20.0NonrevHeatFlow(W/g)-0.4-0.20.00.20.4RevHeatFlow(W/g)-0.4-0.20.00.2HeatFlow(W/g)050100150200250300Temperature(°C)ExoUp135MDSC?無定形PETNonreversingRever何時&為什么運行MDSC?？我需要比熱信息嗎？轉變是一個比熱相關的現象嗎?有被其他效應掩蓋的現象嗎？存在對于標準DSC來講很微弱或很寬的轉變嗎？是否需要更高的靈敏度或分辨率嗎？比熱會在恒溫條件下隨著時間而變化嗎（比如恒溫固化）？136何時&為什么運行MDSC?？我需要比熱信息嗎？41何時&為什么運行MDSC?？對于熔融和結晶–如果熔融過程看起來正常(單個吸熱峰)并且在加熱時無明顯的結晶

，就不必采用MDSC然而,如果熔融過程很復雜,或很難確定樣品是否在加熱時

存在結晶,采用MDSC如果想得到比熱(Cp)–運行MDSC通過常規DSC得到比熱(Q1000由于直接比熱的測量是個例外)采用較高的升溫速率,>10°C/min需要三個實驗基線參考樣(藍寶石)樣品137何時&為什么運行MDSC?？對于熔融和結晶–如果想得普通DSC的局限性不可能在單個DSC的實驗中同時提高靈敏度和分辨率升溫速率快，靈敏度提高，分辨率下降升溫速率慢，分辨率提高，靈敏度下降MDSC?可以解決該問題是因為他有兩個升溫速率基線彎曲度和漂移限制了DSC檢測弱轉變的靈敏度MDSC?消除了基線彎曲度和漂移是在于熱容信號的取得是采用如下等式:

K

x調制升溫速率振幅調制熱流振幅Cp=平均升溫速率

xCp可逆熱流=138普通DSC的局限性不可能在單個DSC的實驗中同時提高靈敏度圖譜很難解釋因為DSC測量的是總熱流MDSC?不僅僅提供總熱流，而且包括熱容的信號和動力學組分4.

很難通過普通DSC準確測量聚合物的結晶度.

準確測量結晶度，需要:確定真正的熱容基線定量測量在加熱過程中有多少結晶在繼續發展139圖譜很難解釋4.很難通過普通DSC準確測量聚合物的結晶度.Application

HeatCapacity