DSC教學(xué)講解課件

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(cè)量樣品吸熱和放熱與溫度或時(shí)間的關(guān)系吸熱熱流入樣品，即樣品吸收外界熱量，為負(fù)值。放熱熱流出樣品，即樣品對(duì)外界放出熱量，為正值。國際標(biāo)準(zhǔn)ISO11357-1:：

DSC就是測(cè)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(guān)系的一種技術(shù)。該熱流差能反映樣品隨溫度或時(shí)間變化所發(fā)生的焓變：樣品吸收能量時(shí)，焓變?yōu)槲鼰?；?dāng)樣品釋放能量時(shí)，焓變?yōu)榉艧帷?差示掃描量熱儀(DSC)DSC測(cè)量樣品吸熱和放熱與溫度或時(shí)EndothermicHeatFlowHeatflowsintothesampleasaresultofeitherHeatcapacity(heating)GlassTransition(Tg)MeltingEvaporationOtherendothermicprocessesEndothermic4EndothermicHeatFlowHeatflowExothermicHeatFlowHeatflowsoutofthesampleasaresultofeitherHeatcapacity(cooling)CrystallizationCuringOxidationOtherexothermicprocessesExothermic5ExothermicHeatFlowHeatflowsDSC與DTA測(cè)定原理的不同DSC是在控制溫度變化情況下，以溫度（或時(shí)間）為橫坐標(biāo)，以樣品與參比物間溫差為零所需供給的熱量為縱坐標(biāo)所得的掃描曲線。DTA是測(cè)量T-T的關(guān)系，而DSC是保持T=0，測(cè)定H-T的關(guān)系。兩者最大的差別是DTA只能定性或半定量，而DSC的結(jié)果可用于定量分析。6DSC與DTA測(cè)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(zhuǎn)變，Tg）MeltingandBoilingPoints（熔點(diǎn)和沸點(diǎn)）Crystallizationtimeandtemperature（結(jié)晶時(shí)間和溫度）PercentCrystallinity（結(jié)晶度）Polymorphism（多種形態(tài)）HeatsofFusionandReactions（熔化和反應(yīng)熱）SpecificHeat（比熱）Oxidative/ThermalStability（氧化/熱穩(wěn)定性）RateandDegreeofCure（固化速率和程度）ReactionKinetics（反應(yīng)動(dòng)力學(xué)）Purity（純度）7DSC:WhatDSCCanTellYouGlasDSC:典型DSC轉(zhuǎn)變溫度熱流->放熱玻璃化轉(zhuǎn)變結(jié)晶熔化交聯(lián)(固化)氧化或分解8DSC:典型DSC轉(zhuǎn)變溫度熱流->放熱玻璃化轉(zhuǎn)變結(jié)熱流型(HeatFlux)在給予樣品和參比品相同的功率下，測(cè)定樣品和參比品兩端的溫差T，然后根據(jù)熱流方程，將T（溫差）換算成Q（熱量差）作為信號(hào)的輸出。功率補(bǔ)償型(PowerCompensation)在樣品和參比品始終保持相同溫度的條件下，測(cè)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(hào)Q（熱量差）輸出。調(diào)制熱流型(ModulatedHeatFlux)在傳統(tǒng)熱流型DSC線性變溫基礎(chǔ)上，疊加一個(gè)正弦震蕩溫度程序，最后效果是可隨熱容變化同時(shí)測(cè)量熱流量，利用傅立葉變換將熱流量即時(shí)分解成熱容成分動(dòng)力學(xué)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(bǔ)償型DSCSample傳統(tǒng)量熱儀內(nèi)部示意圖精確的溫度控制和測(cè)量更快的響應(yīng)時(shí)間和冷卻速度高分辨率基線穩(wěn)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(shè):

1,傳感器絕對(duì)對(duì)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(yuǎn)相同 4,樣品盤及參比盤的質(zhì)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(shè): 1,傳感器絕對(duì)對(duì)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(shù)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(biāo)準(zhǔn)DSC的單項(xiàng)熱流方程To技術(shù)提供的額外項(xiàng)22To技術(shù)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(jí)T0技術(shù)對(duì)DSC測(cè)量的改進(jìn)：T0不需假設(shè)（Q200/Q100DSC):

1,傳感器絕對(duì)對(duì)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(yuǎn)相同高級(jí)To不需假設(shè)(Q2000/Q1000DSC)：

4,樣品盤及參比盤的質(zhì)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(jí)T0技術(shù)對(duì)DSC測(cè)量的改進(jìn)：T0不需假設(shè)（Q200BaselineBowImprovement24BaselineBowImprovement24SuperiorResolutiononaPharmaceuticalSampleAnalysis25SuperiorResolutiononaPharmResolutionImprovement26ResolutionImprovement26AdvancedTzero?Results27AdvancedTzero?Results27MDSC?測(cè)量什么?

MDSC將熱流分解成與變化的升溫速率相關(guān)和不相關(guān)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(cè)量與變化的升溫速率相關(guān)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(guān).MDSC的可逆和不可逆信號(hào)

絕不能

樣品可逆和不可逆性質(zhì)的測(cè)量

28MDSC?測(cè)量什么?MDSC將熱流分解成與變化的升溫速M(fèi)DSC?

原理MDSC?

同時(shí)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(dāng)與普通標(biāo)準(zhǔn)DSC@在同樣升溫速率下的信號(hào)調(diào)制升溫速率目的是為了在得到熱流信號(hào)的同時(shí)得到熱容的信號(hào)29MDSC?原理MDSC?同時(shí)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(diào)制溫度信號(hào)調(diào)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(diào)制溫度信號(hào)調(diào)制溫度平均溫度Modulate+/平均&調(diào)制升溫速率周期平均升溫速率調(diào)制升溫速率0246810Deriv.ModulatedTemperature(°C/min)0246810Deriv.Temperature(°C/min)13.013.514.014.515.0Time(min)34平均&調(diào)制升溫速率周期平均升溫速率調(diào)制升溫速率02468MDSCRawDataSignals…ModulatedHeatFlow

andModulatedTemperature(HeatingRate)Signalshavean“Average”andan“Amplitude”35MDSCRawDataSignals…Modulate調(diào)制DSC總熱流：調(diào)制熱流的傅立葉轉(zhuǎn)換36調(diào)制DSC總熱流：調(diào)制熱流的傅立葉轉(zhuǎn)換36CalculationofReversingCpModulatedHeatingRateModulatedHeatFlowReversingCp37CalculationofReversingCpMod調(diào)制DSC?

不同成分的概念MDSC?DataSignals可逆熱流ReversingTransitions熱容HeatCapacity玻璃化轉(zhuǎn)變GlassTransition大部分的熔融MostMelting總熱流=可逆熱流+不可逆熱流38調(diào)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(zhuǎn)變熱焓松弛EnthalpicRecovery揮發(fā)Evaporation結(jié)晶Crystallization熱固化ThermosetCure蛋白質(zhì)變性ProteinDenaturation淀粉糊化StarchGelatinization分解Decomposition部分熔融SomeMelting調(diào)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(shí)&為什么運(yùn)行MDSC?？我需要比熱信息嗎？轉(zhuǎn)變是一個(gè)比熱相關(guān)的現(xiàn)象嗎?有被其他效應(yīng)掩蓋的現(xiàn)象嗎？存在對(duì)于標(biāo)準(zhǔn)DSC來講很微弱或很寬的轉(zhuǎn)變嗎？是否需要更高的靈敏度或分辨率嗎？比熱會(huì)在恒溫條件下隨著時(shí)間而變化嗎（比如恒溫固化）？41何時(shí)&為什么運(yùn)行MDSC?？我需要比熱信息嗎？41何時(shí)&為什么運(yùn)行MDSC?？對(duì)于熔融和結(jié)晶–如果熔融過程看起來正常(單個(gè)吸熱峰)并且在加熱時(shí)無明顯的結(jié)晶

，就不必采用MDSC然而,如果熔融過程很復(fù)雜,或很難確定樣品是否在加熱時(shí)

存在結(jié)晶,采用MDSC如果想得到比熱(Cp)–運(yùn)行MDSC通過常規(guī)DSC得到比熱(Q1000由于直接比熱的測(cè)量是個(gè)例外)采用較高的升溫速率,>10°C/min需要三個(gè)實(shí)驗(yàn)基線參考樣(藍(lán)寶石)樣品42何時(shí)&為什么運(yùn)行MDSC?？對(duì)于熔融和結(jié)晶–如果想得普通DSC的局限性不可能在單個(gè)DSC的實(shí)驗(yàn)中同時(shí)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?yàn)樗袃蓚€(gè)升溫速率基線彎曲度和漂移限制了DSC檢測(cè)弱轉(zhuǎn)變的靈敏度MDSC?消除了基線彎曲度和漂移是在于熱容信號(hào)的取得是采用如下等式:

K

x調(diào)制升溫速率振幅調(diào)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(gè)DSC的實(shí)驗(yàn)中同時(shí)提高靈敏度圖譜很難解釋因?yàn)镈SC測(cè)量的是總熱流MDSC?不僅僅提供總熱流，而且包括熱容的信號(hào)和動(dòng)力學(xué)組分4.

很難通過普通DSC準(zhǔn)確測(cè)量聚合物的結(jié)晶度.

準(zhǔn)確測(cè)量結(jié)晶度，需要:確定真正的熱容基線定量測(cè)量在加熱過程中有多少結(jié)晶在繼續(xù)發(fā)展44圖譜很難解釋4.很難通過普通DSC準(zhǔn)確測(cè)量聚合物的結(jié)晶度.Application

HeatCapacity

GlassTransitionMeltingandCrystallizationThermoplasticsThermosets

AdditionalApplicationsExamples45Application45如果我們要用DSC測(cè)量比熱怎么辦？當(dāng)f(x)=0時(shí)（沒有動(dòng)力學(xué)相關(guān)現(xiàn)象時(shí)）。樣品熱流可簡(jiǎn)寫為：Q=Cp··m

。通過兩次不同加熱速率對(duì)樣品進(jìn)行測(cè)試即可得到：K為儀器校正系數(shù)1、Cp的測(cè)量46如果我們要用DSC測(cè)量比熱怎么辦？K為儀器校正系數(shù)1、Cp的傳統(tǒng)DSC測(cè)量樣品比熱Cp首先需要確定K值?？梢酝ㄟ^已知比熱的標(biāo)準(zhǔn)材料（如藍(lán)寶石）來確定。

基線的重現(xiàn)性對(duì)Cp測(cè)量影響必須考慮。為了得到更好的Cp數(shù)據(jù)首先要測(cè)試空白基線，然后對(duì)每次樣品測(cè)試結(jié)果進(jìn)行基線扣除。

不要忘記我們?cè)谶M(jìn)行熱流計(jì)算時(shí)的假設(shè)條件。這是測(cè)量誤差的來源之一。K為儀器校正系數(shù)47傳統(tǒng)DSC測(cè)量樣品比熱Cp首先需要確定K值。K為儀器校正系數(shù)傳統(tǒng)

DSC測(cè)量比熱的方法

:48傳統(tǒng)DSC測(cè)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(fù)雜樣品QuenchedXenoy14.79mg10°C/min復(fù)雜樣品66復(fù)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(tài)PET/PC的DSC，PC的Tg在哪里?68無定形態(tài)PET/PC的DSC，PC的Tg在哪里?68MDSC在聚合物共混物中顯示兩個(gè)Tg

MDSC?.318/40/369MDSC在聚合物共混物中顯示兩個(gè)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(zhuǎn)變

75小甜品在冷卻過程中的玻璃化轉(zhuǎn)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(zhuǎn)變10.85mgEpoxyheating@3°/min,afterisothermalcureat100°C81殘余固化隱藏玻璃化轉(zhuǎn)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(cè)試過程中的影響因素831、掃描速度的影響DSC測(cè)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(cè)試低程度的轉(zhuǎn)變、非均勻試樣峰寬、溫度準(zhǔn)確度、分辨率低。要求dT/dt小。小峰尖，分辨率好，對(duì)零級(jí)反應(yīng)的轉(zhuǎn)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(yīng)，動(dòng)態(tài)優(yōu)于靜態(tài)。高傳熱系數(shù)氣體（如H2、He）分辨率高；

低傳熱系數(shù)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(cè)試低程度的轉(zhuǎn)樣品的粒度與形狀對(duì)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(cè)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(duì)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(huán)節(jié)Questionsandanswers93提問與解答環(huán)節(jié)93結(jié)束語

感謝參與本課程，也感激大家對(duì)我們工作的支持與積極的參與。課程后會(huì)發(fā)放課程滿意度評(píng)估表，如果對(duì)我們課程或者工作有什么建議和意見，也請(qǐng)寫在上邊94結(jié)束語

94謝謝聆聽THANKYOUFORLISTENING演講者：XX時(shí)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(cè)量樣品吸熱和放熱與溫度或時(shí)間的關(guān)系吸熱熱流入樣品，即樣品吸收外界熱量，為負(fù)值。放熱熱流出樣品，即樣品對(duì)外界放出熱量，為正值。國際標(biāo)準(zhǔn)ISO11357-1:：

DSC就是測(cè)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(guān)系的一種技術(shù)。該熱流差能反映樣品隨溫度或時(shí)間變化所發(fā)生的焓變：樣品吸收能量時(shí)，焓變?yōu)槲鼰幔划?dāng)樣品釋放能量時(shí)，焓變?yōu)榉艧帷?8差示掃描量熱儀(DSC)DSC測(cè)量樣品吸熱和放熱與溫度或時(shí)EndothermicHeatFlowHeatflowsintothesampleasaresultofeitherHeatcapacity(heating)GlassTransition(Tg)MeltingEvaporationOtherendothermicprocessesEndothermic99EndothermicHeatFlowHeatflowExothermicHeatFlowHeatflowsoutofthesampleasaresultofeitherHeatcapacity(cooling)CrystallizationCuringOxidationOtherexothermicprocessesExothermic100ExothermicHeatFlowHeatflowsDSC與DTA測(cè)定原理的不同DSC是在控制溫度變化情況下，以溫度（或時(shí)間）為橫坐標(biāo)，以樣品與參比物間溫差為零所需供給的熱量為縱坐標(biāo)所得的掃描曲線。DTA是測(cè)量T-T的關(guān)系，而DSC是保持T=0，測(cè)定H-T的關(guān)系。兩者最大的差別是DTA只能定性或半定量，而DSC的結(jié)果可用于定量分析。101DSC與DTA測(cè)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(zhuǎn)變，Tg）MeltingandBoilingPoints（熔點(diǎn)和沸點(diǎn)）Crystallizationtimeandtemperature（結(jié)晶時(shí)間和溫度）PercentCrystallinity（結(jié)晶度）Polymorphism（多種形態(tài)）HeatsofFusionandReactions（熔化和反應(yīng)熱）SpecificHeat（比熱）Oxidative/ThermalStability（氧化/熱穩(wěn)定性）RateandDegreeofCure（固化速率和程度）ReactionKinetics（反應(yīng)動(dòng)力學(xué)）Purity（純度）102DSC:WhatDSCCanTellYouGlasDSC:典型DSC轉(zhuǎn)變溫度熱流->放熱玻璃化轉(zhuǎn)變結(jié)晶熔化交聯(lián)(固化)氧化或分解103DSC:典型DSC轉(zhuǎn)變溫度熱流->放熱玻璃化轉(zhuǎn)變結(jié)熱流型(HeatFlux)在給予樣品和參比品相同的功率下，測(cè)定樣品和參比品兩端的溫差T，然后根據(jù)熱流方程，將T（溫差）換算成Q（熱量差）作為信號(hào)的輸出。功率補(bǔ)償型(PowerCompensation)在樣品和參比品始終保持相同溫度的條件下，測(cè)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(hào)Q（熱量差）輸出。調(diào)制熱流型(ModulatedHeatFlux)在傳統(tǒng)熱流型DSC線性變溫基礎(chǔ)上，疊加一個(gè)正弦震蕩溫度程序，最后效果是可隨熱容變化同時(shí)測(cè)量熱流量，利用傅立葉變換將熱流量即時(shí)分解成熱容成分動(dòng)力學(xué)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(bǔ)償型DSCSample傳統(tǒng)量熱儀內(nèi)部示意圖精確的溫度控制和測(cè)量更快的響應(yīng)時(shí)間和冷卻速度高分辨率基線穩(wěn)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(shè):

1,傳感器絕對(duì)對(duì)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(yuǎn)相同 4,樣品盤及參比盤的質(zhì)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(shè): 1,傳感器絕對(duì)對(duì)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(shù)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(biāo)準(zhǔn)DSC的單項(xiàng)熱流方程To技術(shù)提供的額外項(xiàng)117To技術(shù)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(jí)T0技術(shù)對(duì)DSC測(cè)量的改進(jìn)：T0不需假設(shè)（Q200/Q100DSC):

1,傳感器絕對(duì)對(duì)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(yuǎn)相同高級(jí)To不需假設(shè)(Q2000/Q1000DSC)：

4,樣品盤及參比盤的質(zhì)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(jí)T0技術(shù)對(duì)DSC測(cè)量的改進(jìn)：T0不需假設(shè)（Q200BaselineBowImprovement119BaselineBowImprovement24SuperiorResolutiononaPharmaceuticalSampleAnalysis120SuperiorResolutiononaPharmResolutionImprovement121ResolutionImprovement26AdvancedTzero?Results122AdvancedTzero?Results27MDSC?測(cè)量什么?

MDSC將熱流分解成與變化的升溫速率相關(guān)和不相關(guān)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(cè)量與變化的升溫速率相關(guān)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(guān).MDSC的可逆和不可逆信號(hào)

絕不能

樣品可逆和不可逆性質(zhì)的測(cè)量

123MDSC?測(cè)量什么?MDSC將熱流分解成與變化的升溫速M(fèi)DSC?

原理MDSC?

同時(shí)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(dāng)與普通標(biāo)準(zhǔn)DSC@在同樣升溫速率下的信號(hào)調(diào)制升溫速率目的是為了在得到熱流信號(hào)的同時(shí)得到熱容的信號(hào)124MDSC?原理MDSC?同時(shí)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(diào)制溫度信號(hào)調(diào)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(diào)制溫度信號(hào)調(diào)制溫度平均溫度Modulate+/平均&調(diào)制升溫速率周期平均升溫速率調(diào)制升溫速率0246810Deriv.ModulatedTemperature(°C/min)0246810Deriv.Temperature(°C/min)13.013.514.014.515.0Time(min)129平均&調(diào)制升溫速率周期平均升溫速率調(diào)制升溫速率02468MDSCRawDataSignals…ModulatedHeatFlow

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

不同成分的概念MDSC?DataSignals可逆熱流ReversingTransitions熱容HeatCapacity玻璃化轉(zhuǎn)變GlassTransition大部分的熔融MostMelting總熱流=可逆熱流+不可逆熱流133調(diào)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(zhuǎn)變熱焓松弛EnthalpicRecovery揮發(fā)Evaporation結(jié)晶Crystallization熱固化ThermosetCure蛋白質(zhì)變性ProteinDenaturation淀粉糊化StarchGelatinization分解Decomposition部分熔融SomeMelting調(diào)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(shí)&為什么運(yùn)行MDSC?？我需要比熱信息嗎？轉(zhuǎn)變是一個(gè)比熱相關(guān)的現(xiàn)象嗎?有被其他效應(yīng)掩蓋的現(xiàn)象嗎？存在對(duì)于標(biāo)準(zhǔn)DSC來講很微弱或很寬的轉(zhuǎn)變嗎？是否需要更高的靈敏度或分辨率嗎？比熱會(huì)在恒溫條件下隨著時(shí)間而變化嗎（比如恒溫固化）？136何時(shí)&為什么運(yùn)行MDSC?？我需要比熱信息嗎？41何時(shí)&為什么運(yùn)行MDSC?？對(duì)于熔融和結(jié)晶–如果熔融過程看起來正常(單個(gè)吸熱峰)并且在加熱時(shí)無明顯的結(jié)晶

，就不必采用MDSC然而,如果熔融過程很復(fù)雜,或很難確定樣品是否在加熱時(shí)

存在結(jié)晶,采用MDSC如果想得到比熱(Cp)–運(yùn)行MDSC通過常規(guī)DSC得到比熱(Q1000由于直接比熱的測(cè)量是個(gè)例外)采用較高的升溫速率,>10°C/min需要三個(gè)實(shí)驗(yàn)基線參考樣(藍(lán)寶石)樣品137何時(shí)&為什么運(yùn)行MDSC?？對(duì)于熔融和結(jié)晶–如果想得普通DSC的局限性不可能在單個(gè)DSC的實(shí)驗(yàn)中同時(shí)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?yàn)樗袃蓚€(gè)升溫速率基線彎曲度和漂移限制了DSC檢測(cè)弱轉(zhuǎn)變的靈敏度MDSC?消除了基線彎曲度和漂移是在于熱容信號(hào)的取得是采用如下等式:

K

x調(diào)制升溫速率振幅調(diào)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(gè)DSC的實(shí)驗(yàn)中同時(shí)提高靈敏度圖譜很難解釋因?yàn)镈SC測(cè)量的是總熱流MDSC?不僅僅提供總熱流，而且包括熱容的信號(hào)和動(dòng)力學(xué)組分4.

很難通過普通DSC準(zhǔn)確測(cè)量聚合物的結(jié)晶度.

準(zhǔn)確測(cè)量結(jié)晶度，需要:確定真正的熱容基線定量測(cè)量在加熱過程中有多少結(jié)晶在繼續(xù)發(fā)展139圖譜很難解釋4.很難通過普通DSC準(zhǔn)確測(cè)量聚合物的結(jié)晶度.Application

HeatCapacity