热重分析TGA-完整版资料_精品文档资料下载.pdf

热重分析TGA-完整版资料_精品文档资料下载.pdf

《热重分析TGA-完整版资料_精品文档资料下载.pdf》由会员分享，可在线阅读，更多相关《热重分析TGA-完整版资料_精品文档资料下载.pdf（69页珍藏版）》请在冰豆网上搜索。

热重分析就是在不同的热条件（以恒定速度升温或等温条件下延长时间）下对样品的质量变化加以测量的动态技术。

3WhatTGACanTellYouThermalStabilityofMaterialsOxidativeStabilityofMaterialsCompositionofMulti-componentSystemsEstimatedLifetimeofaProductDecompositionKineticsofMaterialsTheEffectofReactiveorCorrosiveAtmospheresonMaterialsMoistureandVolatilesContentofMaterials热稳定性氧化稳定性组成产品寿命分解动力学反应或腐蚀气氛对材料的影响材料水分和挥发份含量4MechanismsofWeightChangeinTGA?

WeightLoss:

?

Decomposition:

Thebreakingapartofchemicalbonds.?

Evaporation:

Thelossofvolatileswithelevatedtemperature.?

Reduction:

Interactionofsampletoareducingatmosphere（hydrogen,ammonia,etc）.?

Desorption.?

WeightGain:

Oxidation:

Interactionofthesamplewithanoxidizingatmosphere.?

Absorption.Allofthesearekineticprocesses（i.e.thereisarateatwhichtheyoccur）.5DTG曲线微分型曲线TG曲线积分型曲线6初始热分解温度（B、G）反应终了温度（C、H）最大失重速率温度7影影响响热热重重测测定定的的因因素素:

PurgeGasTGA:

AlwayspurgethroughbalancehousingwithdryinertgasTGA:

Onlyintroducereactive/corrosivegasesthroughsamplearea/furnacehousingNitrogenmostcommon.Heliumoftenprovidesbestbaselinebutwillmakefurnaceworkhardathightemperature.Aircansometimesimproveresolutionbecauseofdifferencesintheoxidativestability（versusthermalstability）ofcomponents.气氛不同反应机理的不同。

8TGA:

PurgeGasFlow60ml/min90ml/min10ml/min40ml/minStandardFurnaceEGAFurnace9TestforOxygenContaminationofN2PurgeGas0100200300400500600406080100120-10123Temperature（C）Weight（%）-Deriv.Weight（%/C）320.79C10minuteN2pre-purge+CopperOxalate10EffectofOxygenonCopperOxalateDecomposition300350400450500550600Temperature（C）414243444546Weight（%）HighOxygenMediumOxygenLowOxygen11TGA:

BaselineConsiderationsGoodwaytoquantifyhowtheTGA/SDTisworking.Especiallyimportantformeasuringsmallweightlossesassociatedwithvolatilizationorsmallamountsofresidue.Runclean,empty,taredpan,overtemperaturerangeofinterest,atdesiredheatingrate.Plotweightingvs.temperature.12TGA:

AccurateResiduals-20020406080100120Weight（%）02004006008001000Temperature（C）UniversalV3.9ATAInstruments-2024-2024PolyolefinBaselineExpandedScale0.28%13TGA:

SamplePreparation（cont.）UsebrasstweezerstoeliminatestaticeffectsTareacleansamplepanbeforeeveryrunDistributesampleevenlyoverbottomofpanLiquidsamples-usehermeticpanwithapin-holelid14Platinum（usefulformostmaterials）?

EasytoClean?

Nonporous?

AlloyswithmostmetalsAlumina（Ceramic）?

Corrosives/Inorganics?

LargesamplesAluminum（TGA）（designedforone-timeuse）?

Lowercost?

Lowertemperaturelimit（=600C）TGA:

SamplePanSelection15TGA:

SamplePans-Types/SizesCeramicPlatinumAluminum50L100L100L250L500LPlatinumandAluminumpanshaveattachedwirebail.Ceramicpanshaveremovablewirebail.16EffectofSampleSize020406080100Weight（%）0100200300400500600Temperature（C）Polystyrene17.6mgPolystyrene10.2mgPolystyrene5.4mgPolystyrene2.7mgUniversalV4.2DTAInstruments17EffectofHeatingRate020406080100Weight（%）0100200300400500600Temperature（C）Polystyrene20C/minPolystyrene10C/minPolystyrene5C/minPolystyrene1C/min18MassEffectSemi-crystallinePE436.28癈457.57癈-20020406080100120Weight（%）0100200300400500600Temperature（癈）0.492mg48.422mgUniversalV3.8ATAInstruments19PanShapeEffectAmorphousPMMA365.01癈369.13癈-20020406080100120Weight（%）0100200300400500Temperature（癈）4.6mg;

spreadevenly4.6mg;

intallS.S.pan（150mg）UniversalV3.8ATAInstruments20SampleMorphologyEffectsPET419.58癈424.58癈020406080100120Weight（%）0100200300400500600Temperature（癈）2.9mg;

amorphousPET2.8mg;

crystallinePETUniversalV3.8ATAInstruments2.9mg;

semi-crystallinePET21ShiftinOnsetwithRampRate524.26C563.82C-20020406080100120Weight（%）400450500550600650700Temperature（C）2.5C/min5C/min10C/min20C/minUniversalV3.7ATAInstruments22TimetoCompleteDegradation-20020406080100120Weight（%）20406080100120140160180Time（min）2.5C/min5C/min10C/min20C/minjUniversalV3.7ATAInstruments23Q5000IRHigh-HeatingRateTGAAnalysis24TypicalApplicationsThermalStabilityCompositionalAnalysisOxidativeStability25ThermalStabilityofPolymersMethodLog:

1:

Selectgas:

1-N22:

Ramp20.00C/minto650.00C3:

2-Air4:

Ramp20.00C/minto1000.00CPVCPMMAPET650.00C55.59%650.00C5.928%LDPEPEEK650.00C14.32%020406080100Weight（%）502504506508501050Temperature（C）26BlockversusRandomCopolymers0100200300400500050100Temperature（C）Weight（%）S-MSRANDOMS-MSBLOCKP-MSPSsize:

8mgprog:

6C/minatm:

300Pavacuum27EffectofEpoxyCureTemperature260280300320340360380400420440020406080100Temperature（C）Weight（%）