高物高分子物理課件chapter

1、Chapt.Molecular andChapt.Molecular andTransitions of S 6.1Molecularmotionsof 特點(diǎn), 基本類(lèi)型e Glass transitionof意義, 表征, 理論Viscous flowof 特點(diǎn), 表征, 影響16.1高聚物的分子熱運(yùn)動(dòng)1. 主要特運(yùn)動(dòng)單元的多重6.1高聚物的分子熱運(yùn)動(dòng)1. 主要特運(yùn)動(dòng)單元的多重:relaxation與運(yùn)動(dòng)單元有關(guān)與溫度有關(guān)xx etx0 0eE/a指數(shù)形式bWLF方程(3) 與觀察時(shí)的時(shí)間標(biāo)尺t2ViscoelasticityofElasticityandHookeslawViscoelas

2、ticityofElasticityandHookeslawdescribesthebehaviorofa linearelasticsolidNewtonstofa linearviscousSpringasam Modulus:Dashpotasa :Viscosity粘度Hookeslaw: =stress應(yīng)力Newtonslaw: = strain應(yīng)變3Elasticity+ Viscosity= Viscoelasticityd2 1 2Elasticity+ Viscosity= Viscoelasticityd2 1 2 1 d 1 d MaxwellForstress rela

3、xation, d/dt=tE tmAttime t =0, =0Relaxationtime: = 4t expt 粘彈性-力學(xué)松弛行粘彈性-力學(xué)松弛行52. 力學(xué)狀態(tài)與熱轉(zhuǎn)T次級(jí)松形變不可回復(fù)高彈性力學(xué)性質(zhì)普彈性運(yùn)動(dòng)單元2. 力學(xué)狀態(tài)與熱轉(zhuǎn)T次級(jí)松形變不可回復(fù)高彈性力學(xué)性質(zhì)普彈性運(yùn)動(dòng)單元鏈段鏈段鏈段分子實(shí)驗(yàn)不可測(cè)范松弛時(shí)間實(shí)驗(yàn)可測(cè)實(shí)驗(yàn)可測(cè)6Semi-crystallineor crystalline TmTfCrystalline6.216.21237GlassTransitionas a RelaxationsThermalhistoryGlassTransitionas a Relax

4、ationsThermalhistorydependenceof 1:fast2:slowTemperature dependence of the specific volume of PVA, measured during heating.Dilatometric (膨脹計(jì)法results after a quench to 20C, followed by 0.02 100h of storage. (Kovacs, A. J. THochpolym. Forsch. 1966,3, 8V4. 現(xiàn)象和實(shí)驗(yàn)表(1(2(3玻璃高彈4. 現(xiàn)象和實(shí)驗(yàn)表(1(2(3玻璃高彈粘流 0(495Fre

5、eVolume Freevolume: aconcept5FreeVolume Freevolume: aconceptusefulindiscussing chas viscosityandinThe segmentalmotionof polymer chain requires more volumeOccupied volume: filled circles; free Holetheoryofliquid: the liquidconsistsofmatterand holes. The largervolume ofliquid when comparedto the cryst

6、alis representedby a number of holes of afixedvolume. The holesrepresent zed freevolume, whichcanredistributedby movementorcollapse inone placeand creationinFreeVolume dV VT dT The coefficient of thermal expan (CTE,熱膨脹系數(shù)isconstant for the occupiedvolumeforbothtemperaturebelowand above The volume-tem

7、perature fora typical amorphous polymer Vf: free volume at T Tg (Vf)T: free volume at T Tg Vt: total volume at T Tgthe temperature below T gthefreevolumeisconstant; and the volumeFreeVolume dV VT dT The coefficient of thermal expan (CTE,熱膨脹系數(shù)isconstant for the occupiedvolumeforbothtemperaturebelowan

8、d above The volume-temperature fora typical amorphous polymer Vf: free volume at T Tg (Vf)T: free volume at T Tg Vt: total volume at T Tgthe temperature below T gthefreevolumeisconstant; and the volumewillincreasewithtemperature when temperature exceed TgV0:occupied volume(determined dV dV T T vande

9、reraction +VVTV dT dT gf0grggdV/dT):CTEoftheglass- andrubber-geT dV dV dV dV V VT TT dT dT dT dT g fffT TTTdV dV VfTTf dT dT ggfVg f T Tg gfT fg(T Tg1 dV 1 dV dT dT fVVgggFreeVolume Theory AexpBV /VRelationof the molecularmobilityto free volume: Doolittle equationln V (T)FreeVolume Theory AexpBV /VR

10、elationof the molecularmobilityto free volume: Doolittle equationln V (T)(T(TgV B 0Vf (TVf (Tg)(TgfVf (TVf (TNormalizedfreeTV (T)V (TV (T0f0fg f TTg fT (T B 1 1 T fg /f TTg 2.303 fg(TTglog(Tlog(TWLF (Tg51.6(TTg (Tgfg 0.025equalto 1fg4.8104/ffAppendix:Doolittle equation & Einstein Doolittle AexpBV /A

11、ppendix:Doolittle equation & Einstein Doolittle AexpBV /Vandthevolume fraction1InV V0 /Vfsf0Einstein Forthe solutionof impenetrablespheresof radius R, EinsteinderivedEffectiveviscosityof 0 12.5sp.69of ChainMorerigidchainpresenthigher Tvs.mg/Tm 1/Forsymmetricalbackbone, MolecularweightTg /Tm 2/ChainM

12、orerigidchainpresenthigher Tvs.mg/Tm 1/Forsymmetricalbackbone, MolecularweightTg /Tm 2/ForasymmetricalT () FoxggMT nmHeatingratemTgvs. eE/ 0T 高度柔性和剛性鏈tgbt1/v 升溫速度t停留時(shí)間Tg f中度剛性鏈強(qiáng)迫高彈形變Tg1Tt tT1s1f1tstf g1tf g2EffectsoffilmEffectsoffilmthickness onTsui,OKC,Macromolecules, 34,5535Glass transition of pol

13、ymer Somepolymerblends exhibitpartial miscibility. Theyhave amutual, solubilityindicatedby Glass transition of polymer Somepolymerblends exhibitpartial miscibility. Theyhave amutual, solubilityindicatedby a hetwopanyingaphaseitionof the blend. monisthe type ofindicatedby the presenceof only single l

14、edPartialww1 Fox-FloryTgof lend Plasticization of PVC: Tg as function of di(ethylhexyl)-DSC curves of 50mass-% blends of PS and poly(-methyl styrene) at aandPS as a function of content.(Bair, H. E. Polym. Eng. Sci. 1970, 10, 247.)latecontent. (Wolf, heatingrate of 10 K/min. (Lau, S.F.; etc. Macromol

15、ecules 1982, 15, 1278.)Kunststoffe 1951, 41, EffectsofTg onEffectsofTg onMorphologyof PolymerTanakaH,J PhysCondens12,R207ChengSZD,KellerA,Ann RevMaterSci,28,5336.3Viscous Flow ofTherheological6.3Viscous Flow ofTherheological properties流變性質(zhì)polymersisextremelyimportantRheology: The study of the deform

16、ation and flow of matter.Characteristicofpolymerviscous 1. 鏈段的蠕動(dòng)實(shí)現(xiàn)整個(gè)分子的遷移2. Characteristicofpolymerviscous 1. 鏈段的蠕動(dòng)實(shí)現(xiàn)整個(gè)分子的遷移2. 不符合流體的規(guī) Characteristicofpolymerviscous 時(shí)伴有高彈Characteristicofpolymerviscous 時(shí)伴有高彈形Considera steadysimpleshearShearShearDie-(出口長(zhǎng)大Extrudate swell observed for a melt of PS for

17、various shear ratesand temperatures. (Burke, J. J.; etc.Characterization of Materials in Research, Syracuse Univ. Press, Characterization ofviscous三種最基本的(形變)-shearviscosityCharacterization ofviscous三種最基本的(形變)-shearviscosity(形變)-tensileviscositya.剪切b.拉伸velocityc.壓縮bpresibleMelt viscosities of dhMelt

18、viscosities of dhs1-2-a dha s0 0 sint /2 sin t0Measurementofsheareter -anMrHRhrtanMeasurementofsheareter -anMrHRhrtan dv r h b a3Theflowcurveofpolymer td0零切粘pTheflowcurveofpolymer td0零切粘pplog00dependentof Criticalmolecularentanglement纏結(jié)limit0dependentof Criticalmolecularentanglement纏結(jié)limitM Mc M Mc RouseMMWWMM0Tubeion)0EffectsofTemp.,ShearRateShearStress on分子量與分子分子量與分子量分溫度-Vogel-Fuchler 方 Aexp/T T0 剪切應(yīng)力與剪切速鏈結(jié)構(gòu)-支分子結(jié)構(gòu)的柔順?lè)肿?. 外力作Normal stressdifferenceandElasticeffectson viscous flow of polymersAF