玻璃化转变过程对升温速率依赖性

335200710()JOURNALOFDONGHUAUNIVERSITY(NATURALSCIENCE)Vol33,No.5Oct.2007:16710444(2007)05056904梁建勋,于伟东*(,201620):动态机械热分析实验中,玻璃化转变的一个主要特征就是模量的显著下降.以此为基础,在理论上推演了升温速率对玻璃化转变的影响.聚氯乙烯(PVC)因其是典型的非晶高聚物被选作为实验验证材料.实际测量结果与理论预测值的对比表明,这一理论可以比较好地预测升温速率对非晶高聚物玻璃化转变温度区间的影响.同时据此理论预测的升温速率对模量变化率的影响也得以由实验数据验证.:玻璃化转变;活化能;温度依赖性:TB302.3:AHeatingRateDependenceofGlassTransitionLIANGJianxun,YUWeidong(CollegeofTextiles,DonghuaUniversity,Shanghai201620,China)Abstract:Atheoreticalstudyontheheatingratedependenceofglasstransitionisconducted,andanewmodelexplainingthephenomenonthattheglasstransitiontemperatureincreaseswiththeheatinggoingupwasdeduced.TheverifyingexperimentswerealsoperformedinPolyvinylchloride(PVC).Theexperimentalresultsshowedthatthismodelcouldquantificationallypredicttheheatingratedependenceofglasstransitiontemperature.Furthermore,thepredictionaboutthemodulusvaryingrateinglasstransitionwasvalidatedbyexperimentalresults.Keywords:glasstransition;activationenergy;temperaturedependence,,[1]..,.1关于升温速率对玻璃化转变温度区间影响的理论推导,:(1),,Tg;,,Tg,Te,.(2)EMs,Me.,.(3)E.*:20060215:(1978),,,,.Email:[e-mail](),,,Email:[e-mail]570()33E,Tg(),:Ms-Me=KTgTg(1):KTgTg;Tg,(2).Tg=0exp(E/RTg)(2):0;R.,,:dT=dtdt=1dT(3):.,T:dM=KTdt=Ms-Me0exp(E/RT)dt=Ms-Me0exp(E/RT)1dT(4):KTT.(4):dM=TeTgMs-Me0exp(E/RT)1dT(5):Ms-Me=TeTgMs-Me0exp(E/RT)1dT(6)(6),FrankKameneskii[2],10RT2eEexp-ERTe1+10RT2gEexp-ERTg(7)1+10RT2gEexp-ERTg=C,(7):Te=E2R!lambertw120CR/E(8)Matlablambertw(x):w!exp(w)=x,w=lambertw(x).2实验2.1(PVC).1000gPVC650gTCTM20gCa/ZnC10250g68g80gA.,120∀50min.200∀1mm.2.2PEDMA7E.,1mm3mm4mm.,5∀/min;,1Hz.3结果与讨论,,.,,,,.,,,,.1PVC,40∀.PVC,,.,.2.5,:571.,.,.1PVCFig.1Thecurvesofelasticmodulus,lossmodulusandlosstangentofPVC2PVCFig.2ComparisonofthecurvesbetweenlossmodulusandelasticmodulusdifferentialofPVC,Arrhenius,WLF[3].WLFVogle[4]:=Aexp(B/(T-T#0))(9),T#0B.,,,[5],Tg().50∀.,PVC[5]:=0exp(!/(RT(T-Tmg)(10):E!/(T-Tg)m.PVC1,(10),Tg-65∀,:0=1.03!10-11sE255k=69.9kJ/mol,,,.1PVCTable1TheglasstransitiontemperatureofPVCmeasuredunderdifferentfrequencies/Hz1510Tg/∀-18-16-130E(8),,2.2PVCTable2ThetheoreticaltemperatureattheendofglasstransitionofPVCunderdifferentheatuprates/(∀∃min-1)24681015Te/∀-0.94.98.511.113.116.8,3.3,PVCPVC,,PVC572()33.PVC,,.3PVCFig.3ComparisonbetweenthetheorelicalandmeasuredtemperatureofPVCglasstransitionunderdifferentheatuprates(8)2,.,.,,.,,,.45.4PVCFig.4PVCmodulusvaryingratevstimeunderdifferentheatuprates5PVCFig.5PVCmodulusvaryingratevstimeunderdifferentheatuprates4结论.,.,,,..,,,.[1],,.[M].:,1990:258.[2],.[M].:,2001:28.[3]CHENHY,STEPANOVEV.CreepBehaviorofAmorphousEthyleneStyreneInterpolymersintheGlassTransitionRegion[J].JofPolymSciencePartB:PolymerPhysics,1999,37:23732382.[4]LINJR,CHENLW.MechanicalViscoelasticModelandWLFRelationshipinShapeMemorizedLinearEtherTypePolyurethanes[J].JofPolymResearch,1999,6:3540.[5],.[J].,1997,(6):726729.