流变学基础及应用PPT课件

流变学基础及应用,S,MZ,HU,HH,Welcome,使用牙膏时挤出要容易，挤出后要求挺括，在牙刷上不能下陷，刷牙时又要轻松，这就是要求牙膏遇剪切时粘度迅速下降，而静止时又要具备一定的屈服应力，以保持坚挺。,牙膏一个典型的流变学问题,提纲,I.流变学基础1流变学定义及发展历史2.粘度计及流变仪简介3.稳态流变学4.动态流变学4.1弹性行为及剪切模量4.2粘弹性行为4.3蠕变测试4.4弛豫测试4.5振荡测试II.PhysicaMCR300流变仪简介III.PhysicaMCR300流变仪应用演示,I.流变学基础,Thepersoninthepicture:ThomasG.Mezger,RheologistofAnton-Paar,1流变学及其发展历史,什么是流变学？流变学：研究物质流动和变形的科学Rheology=thescienceofdeformationandflowofmatter(SocietyOfRheology,SOR),希腊语:rheos=toflow，流动,流动行为,www.physica.de,变形行为,古代“万物皆流”1676虎克定律：弹性固体（形变与受力成正比）1687牛顿定律：粘性液体（流动阻力与流动速度成正比）1905爱因斯坦：悬浮液粘度方程（h=hs(1+2.5f)）1920宾汉（Bingham）提出“流变学”概念1945首台旋转粘度计面世（Brookfield）1951首台旋转流变仪Rheogoniometer（Weissenberg）自1970年开始，流动曲线测试代替以前的单点测试自1980年开始，大规模使用数控和计算机，流变学得到较大发展,流变学的发展历史,中国的流变学,“我国流变学的应用研究起步较晚，20世纪60年代还只有个别自发研究，目前的应用研究领域较少，甚至连流变学赖以发展的聚合物加工行业也知之不多。以塑料制品为例，塑料厂引进的模具吃进口的聚合物粒子时，制品光滑、美观，可以和国外的同类产品相媲美，而一旦换成国产原料粒子时，产品质量就下降。这是因为所使用的模具是按国外原料的流变性能设计的，而国产原料的流变性与进口原料并不完全相同，所以制品质量下降。尽管生产厂对模具进行完善修改，但也只是凭经验做机械上的改动，并未考虑到粒子的流变性。”江体乾,流变学的研究内容,流变学的研究范围及方法,物质状态,性能表现,依据原理,研究方法,稳态流变学,动态流变学,SimpleTestMethods,铲刀试验（troweltest）-高粘流体：“稠”-低粘流体：“稀”,手指试验（fingertest）-粘稠：“长”-稀薄：“短”,2流变行为的研究工具粘度计及流变仪,定性！,简单测试,Bostwick稠度计（Consistometer）,1samplecontainer,max.100ml2gate,tobeopenedbyaspring3scaledflowpath,测定流体（如番茄酱等）在一定时间内流过的长度,schematicpresentationofaBOSTWICK-constistometer,粘度计,Falling-BallViscometers,DIN53015ISO12058,measuringtubeincludingtheball,stand,thermometer,jacket,fortemp.control,落球粘度计,HAAKE,GENEQ,e.g.forpastesandpaste-likeprintinginks,weight,printingink,fallingrod,fallingrodviscometer(Laray),Falling-RodViscometers,落杆粘度计,accordingtoASTMD803andD1545,checkmark,Gasbubblerisesafterturningthetube.Viscosityevaluationbycomparisontoasetoftubes,气泡粘度计,BubbleViscometers,Water-Clock(Klepsdra)fortimemeasurementssince3500yearsinEgypte.g.5lcorrespondsto6minflowtime,流杯,FlowCups,measurementoftheflowtimedeterminationofthekinematicviscosity,流杯,FlowCups,ISODINFord(ASTM)ZahnEnglerShell,DINISO,流杯,CapillaryViscometers,玻璃毛细管粘度计,Stormer粘度计,Preset:constanttorque(shearstress)appliedbyafreefallingweight(ingrams)Result:rotationalspeedofthemeasuringsystem,Krebsmeasuringsystem(Paddle)asarelativemeasuringsystemdesignationinKrebsUnits,KU,Brookfield粘度计,spindlesasrelativemeasuringsystems:cylindersdiskspinsT-bar,旋转流变仪绝对测量系统,圆筒状转子（Cylinder）notrecommendedforpastes(airbubbles),锥板转子（Cone-Plate）withdispersionsonlyusefulforparticlesunder5m,平行板（Parallel-plates）usefulforgelsandpastes,旋转及振荡流变仪（rotationalandoscillatoryrheometers）accordingtoDIN53019andISO3219,HAAKE旋转流变仪,HAAKEExtenCaBer1,HAAKERheoScope,HAAKERheoStress1,HAAKERheoStress600,HAAKERotoVisco1,TA旋转流变仪,AR500,AR1000,AR2000,ARES,ARES-1s,ARES-rda,ARES-rfs,Bohlin旋转流变仪,BohlinCVO,BohlinC-VOR,BohlinGemini,BohlinV88,Physica旋转流变仪,RheolabMC1,SmartPave,MCR300、500,MCR301、501,ACS16/32,毛细管流变仪,Poiseuille-Hagen定律,毛细管流变学的基础!,DP,2R,毛细管流变仪,HAAKERheoCapS20,HAAKERheoCapT1000,RH7D2.wideMMD,w%rel.amountMg/molmolarmass,RelaxationTest,RelaxationTest,RelaxationModulus,RelaxationTimeSpectrum,RelaxationTimeSpectrum,MolarMassDistribution,OscillatoryTests:Basics(1),Two-Plate-ModelIdealelasticBehaviorofatotallystiffsample(e.g.stone,orsteel)noshiftbetweenthesinecurvesofshearstressandsheardeformation:thecurvesofandareinphase,4.5振荡实验(OscillatoryTest),OscillatoryTests:Basics(2),Presetting:constantfrequencyandconstantamplitude,here:withthestrain(deformation)amplitudeResult:Inmostcasesthesamplesshowviscoelasticbehaviorwiththephaseshiftbetweenthesinecurvesofpresettingandresult.,physically:GforthestroredandGforthelost(dissipated)deformationenergytand1=G/Gdampingorlossfactor（衰减或损耗因子）asquotientoftheviscousandelasticportions,OscillatoryTests:Basics(3),VectordiagramG*Pacomplexshearmodulus复（数）剪切模量elasticitylawofHooke(foroscillation):GPastoragemodulus,elasticportion储能模量弹性模量GPalossmodulus,viscousportion耗能模量粘性模量oftheviscoelasticbehavior,OscillatoryTests:Basics(4),Vectordiagramh*Pascomplexshearviscosity复（数）剪切粘度hPas=G/w=(tAsind)/(gAw)hPas=G/w=(tAcosd)/(gAw),h,h,h*,d,RawDataandRheologicalParameters,振幅扫描（AmplitudeSweep）,Presetting:Result:constantfrequencyandStorageModulusG(elasticbehavior),variablestrain(deformation)LossModulusG(viscousbehavior),limitingvalueotthelinearviscoelastic(LVE)range,limitingvalueoftheviscoelasticrange,AmplitudeSweep,AmplitudeSweep,=101/sT=25C,AmplitudeSweep,=101/sT=25C,coat1:GG,coat2:GG,comparisonoftwospraycoatings,AmplitudeSweep,comparisonoftwocoatings,AmplitudeSweep,=101/s,temperaturedependenceofbutter,AmplitudeSweep,=101/sT=23C,comparisonoftwostarchgels,AmplitudeSweep,=101/sT=23C,comparisonoffourstarchgels,频率扫描（FrequencySweep）,Presetting:constantamplitude(withintheLVErange)andvariablefrequency,FrequencySweepofanUnlinkedPolymer,g=10%T=23C,FrequencySweep:UnlinkedPolymers,Maxwellliquidthepositionofthecrossoverpoint(basedonasingleofGandGisdependingontheMaxwellmodel)molarmassM(here:M1M2),FrequencySweep,g=10%T=180C,comparisonoftwoPEmelts,FrequencySweep,g=1%T=170C,crosslinkedPE:GG,unlinkedPE:GG,comparisonofunlinkedandcross-linkedpolymers,FrequencySweep:Cross-linkedPolymers,Gels,Dispersions,polymerswithdifferent(1)polymerwithunlinkedmoleculesdegreesofcross-linkingandanarrowMMD(2)polymerwithunlinkedmoleculesandawideMMD(3)sparselycross-linkedpolymer,flexiblegelordispersionwithlowstructuralstrengthatrest(4)denselycross-linkedpolymer,rigidgelordispersionwithhighstructuralstrengthatrest,FrequencySweep,g=1%T=23C,stabledispersion:gelcharacterwithGGatlowfrequenciesinstabledispersion:liquidcharacterwithGGatlowfrequencies,comparisonoftwocoatings,FrequencySweep,g=1%T=23C,stabledispersion:noh0plateauinstabledispersion:withh0plateau,comparisonottwocoatings,FrequencySweep,g=0,3%T=20C,stabledispersion:gelcharacterwithGGatlowfrequenciesinstabledispersion:liquidcharacterwithGGatlowfrequencies,comparisonoftwocosmeticlotions,步进实验：触变性（StepTest:Thixotropy）,low-shearconditionshigh-shearconditionslow-shearconditions,stateofreststructuredecompositionstructureregeneration,asoscillatorytestwith3intervals,Time-DependentStructureDecompositionandRegeneration,g1=g3=0,2%g2=100%=101/sT=23C,3xoscillation,Whatareyoudoing?,Waitingforketchup,Time-DependentStructureDecompositionandRegeneration,g1=g3=0,3%=101/sdg/dt=1001/sT=23C,Osc./Rot/Osc.,Application:AutomotiveCoatings,a)Plastisols:seamsealing,underbodyspraying,cavityconservationb)Primerc)Coatings:filler,basecoat,topcoat,clearcoat,Time-DependentStructureRegeneration,g1=g3=0,2%dg/dt2=150001/s=101/sT=23C,comparisonof3spraycoatings,StepTest:DecompositionandRegenerationoftheStructure(ThixotropicBehavior),a)rotationaltests(3intervals),result:time-dependentviscosity(onlyviscousbehavior!)b)oscillatorytests(3intervals),result:twotime-dependentfunctionsG(viscous)andG(elastic):viscoelasticbehavior,Temperature-DependentSofteningandMelting,g=1%=101/smeltingtemperatureTm=215C,TemperatureCurve,1=0,1%(forT35C)=101/s,polymermodifiedbitumen(PMB),TemperatureCurvesofPolymers,amorphouspartiallycrystallinecross-linkedTg.glasstransitiontemperatureTm.meltingtemperature,TemperatureCurve,=0,1%;1%;10%=101/sglasstransitiontemperature:Tg=-62C(Gmax)Tg=-39C(tandmax),polymermeltwithGGathightemperatures,unlinkedpartiallycrystallinepolymer,TemperatureCurve,glasstransitiontemperatureTg=-22C(Gmax)Tg=-16C(tandmax)nomeltingasGGathightemperatures,g=0,25%=101/s,cross-linkedpolymer,TemperatureCurvesofPolymers,ComparisonofG(T)curvesofpolymerswithdifferentinternalstructures:(1)amorphous,(2)partiallycrystalline,(3a)denselycross-linked(thermoset)and(3b)sparselycross-linked(elastomer).,Temperature-DependentBehavior,meltingorcrystallizationofdispersionspresetting:constantshearconditions(amplitudeandfrequency),Tk.crystallizationtemperature,result:steepdecreaseorincrease,resp.,inanarrowtemperaturerange,Temperature-DependentCrystallization,g=0,1%=101/scrystallizationtemperatureTk=-1C,TimeorTemperature-DependentBehavior,gelformation,hardeningorcuringprocesspresetting:constantshearconditions(amplitudeandfrequency),result:time-dependenttime-dependenttemperature-dependentGcurveGandGcurvesGandGcurvestCR.timepointatthetSG.timepointofTCR.temperatureatthebeginningofsol/geltransitionbeginningofgelformation,hardening,(withG=G)gelformation,hardening,curingorchemicalcuringorchemicalreactionreaction,Time-DependentCuring,g=0,1%=101/s,epoxypowdercoatingat3differenttemperatures,Time-DependentCuring,g=0,1%=101/spreset:T=T(t),Time-DependentUVHardening,g=0,1%=101/s,Temperaturepeakduetotheexothermiccrosslinkingreaction,Temperature-DependentGelFormationandCuring,g=0,2%=101/s,onsetofgellationT=65CendofcuringT=96C,fromaplastisolpastetoanelastomer,Temperature-DependentMeltingBehaviorandCuringReaction,g=0,1%=101/s,Ih*minIatT=129C,epoxypowdercoat,Filmreferencetemperature:T=170C,.,MasterCurveofaPSmelt,Time/TemperatureShift,MasterCurveofPSmelt2,MolarMassDistribution,basedontheMasterCurveofdiagram10.10,RotationalandOscillatoryRheometers,functionalprinciples:,components:A.driveL.bearingMS.measuringsystem(hereCP)PS.positionsensorR.controllerparameters:M.torquen.rotationalspeed.deflectionangle,presetting:presetting:presetting:ornMornHerethedriveisseparatedfromtheMStestresult:testresult:testresult:MornM,基础研究产品开发质量控制,MCR500MCR300MCR100MCR50MC10,PhysicaMCR300：应用范围,MCR=ModularCompactRheometer,PhysicaMCR300测量系统：同轴圆柱转子,同轴圆柱转子（CoaxialCylinder）系统别称：同心圆筒式（ConcentricCylinder）,组成：悬锤（bob）+测量杯（cup）方式：-Searle模式：悬锤运动，杯子不动大多数流变仪采用，缺点：采用高速测量低粘液体样品时易出现Taylor漩涡-Couette模式：悬锤不动，杯子运动极少流变仪采用，可克服Taylor漩涡，但杯子必须密封，以防止控温水浴的流体进入要点：-低粘流体宜采用较大的转子系统（直径大，剪切面积大），高粘流体宜采用宜采用较小的转子；-所有的ISO转子，剪切速率仅与转速有关而与直径大小无关。,优点：-即使在高剪切速率下，液体都不会流出测量杯；-测量杯的表面积较大，控温效果好；-即使出现爬杆效应，环空中也会充满被测样品；-砂磨和有刻痕的转子可防止“壁滑效应”；-可使用样品盖防止容积蒸发缺点：-试样用量大；-在浆状样品中易产生气泡；-清洗耗时,PhysicaMCR300测量系统：双间隙转子,Double-Gap系统,适合测量低粘样品外壁和内壁都受剪切力作用，剪切面积大控温容易，可通过测量杯的中央突出部分控温,圆柱状转子的特点圆柱状转子主要针对需要高剪切速率的实验而设计的，因此剪切间距较小在旋转试验中，可能会出现试样的剪切发热现象，尤其是在剪切速率高于10,0001/s时很容易发生由于制造的困难，间距只能销到一定程度，对于超高剪切速率，例如，1,000,0001/s，宜采用高压毛细管流变仪,PhysicaMCR300测量系统：锥板转子,Cone-Plate系统,1976年左右标准化，1993年左右开始大量使用在测量低粘样品时，容易出现二次流动现象，并导致湍流和增大流动阻力，样品也会飞溅出测量范围低粘液体宜采用较大的转子，因为其剪切面积较大；反之，高粘样品宜采用较小的转子,一旦角度确定，剪切速率就确定，与半径无关锥尖有一较小的平面，因此锥板之间有一定间距，现在的恶流变仪都采用自动设定此间距装样,理想状况实际操作很难,正确,试样偏少,PhysicaMCR300测量系统：锥板转子,优点-剪切十分均匀因为锥-板之间的间距中的剪切速率都相同（大部分研究人员都偏好锥板系统）-试样用量小-不容易在试样中产生气泡-清洗方便,缺点-如果测量分散液体系，其离子尺寸受限；不能测量固体和具有三维结构的试样-高粘试样，需要很长的弛豫时间达到平衡，有时长达30分钟-无法使用砂磨或带刻痕的转子，因为无法确定精确尺寸-试样容易飞溅，容积易挥发-控温不方便,PhysicaMCR300测量系统：平行板转子,Parallel-Plate系统,间距H圆板半径R利用高剪切速率测定低粘液体时，已出现二次流动效应，从而导致湍流和流动阻力增大,低粘液体宜采用较大的测量体系，高粘试样宜采用半径较小的转子剪切速率不恒定，因为其取决于到轴心的距离,优点-可以测定含有较大颗粒的分散也和具有三维结构的试样、软固体和硬化材料-可以快速测定硅橡胶之类的高粘试样-可以通过调节板的间距而改变剪切速率范围-如果板间距较大，可以把因升温而造成的热膨胀效应将到最低-清洗方便-可使用砂磨和