高分子流變學(xué)-lecture-4measurements依靠旋轉(zhuǎn)運動產(chǎn)生簡單剪切流動可以用來快速確定材料黏性

§4.2.2 彈性等方面的流變性能。20031先者(eoetricScietiic)的收購，從此世界上最著名旋轉(zhuǎn)流變儀品牌ARES全部由位 特華州TA公司總部進(jìn)行生產(chǎn)，繼續(xù)供應(yīng)給全球的流變儀市場＝DesignofCR轉(zhuǎn)速控制measuring驅(qū)動一個夾具，測量產(chǎn)生的力矩 )，即應(yīng)力應(yīng)變控DesignofCS應(yīng)力控制measuring施加一定的應(yīng)力，測量產(chǎn)生的旋轉(zhuǎn)速度（searle,1912出的），即產(chǎn)生的應(yīng) ConeandParallelConcentrated

Couette Operateundersteadyshearconditionsoroscillatorymode錐板/平行板夾測量材料范圍高分子溶流體平行板夾間距可推薦0.2to2.5同心圓筒夾對應(yīng)力敏感性材料的面積效錐-板粘度計錐‐板之間的夾角o小于4o，tano約等于剪切速率與半剪切速率與半徑無關(guān)，正是錐-板粘度計的特點半徑為r，厚度為dr的圓環(huán)處的微扭矩為扭矩為. .2. 2R3剪剪切速率恒定，在確定流變學(xué)性質(zhì)時，不對流動動力學(xué)作任何假設(shè)，不需要流變學(xué)模3。多相體系誤差大（懸浮液和共聚物4。避免用錐板結(jié)構(gòu)進(jìn)行溫度掃樣品的FirstNormalStressDifferencein剪切速率是恒定的，故錐板是測量法向應(yīng)力差的理想結(jié)N111

2FR

F為作用在板上的Thefirstnormalstressdifferenceisverysensitivetochangesinthehighmolecularweighttail.EvenamoderatedegreeofheterogeneityinthemolecularweightdistributioncanleadtolargeincreasesinN15。平的表面更易進(jìn)行精度檢dp 分散粒子直h當(dāng)間距很小時（h/R<<1），或在低轉(zhuǎn)速下，慣性可穩(wěn)態(tài)條件下的速度分半徑為r，厚度為dr的圓環(huán)處的微扭矩為扭矩為與錐-板粘度計的區(qū)別是是半徑r的函MM2h22.粘度的對非 流體，因剪切速隨徑而變，粘與扭矩nw型：

T

R

2dr

R(r)rdr 3

替 r/T2h

R R

Tdd

R 3

RRR2R RR

)

0第一、二法向應(yīng)N

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1dlnF R)N2

R

2dln R第二法向應(yīng)力差很N

2F

1dlnF R)1(

R

2dln RParallelPlate-EffectofIncreaseShearIncreaseShearIncreaseShearConcentricDisk

Coaxial‐CylinderCoaxialCylinder Bestforlowviscositysystems,o<100GoodforrelativelyhighshearNotsuitableforpolymer(r)M(Ri2r2RhM=torque,=rotationalspeed,流變儀的UsefulnessofShearViscosityResinproducersusuallyonlygivetheMELTFLOWShearviscosityisrelatedtomolecularweightandthereforeitsknowledgeisveryimportantinmaterialViscosityernstheflowofpolymersinsideprocessingequipment.Flowratesandpressuredropsdependontheviscosityvalue–KnowledgeofviscosityforthewholerelevantshearraterangeisYouneedtodeterminetheshearviscosityifyouwantdesigndies,todeterminepressuredrop,flowratesTheHAAKERheoScope1isauniquecombinationofanopticalmicroscopeanda cameraintegratedunderneaththetemperaturecontrolledbaseplateofauniversalplate&conerheometer(HAAKERheoStress1).Thissimultaneousrecordingofdataandimagesallowstherelationshipbetweentherheologicalpropertiesandthestructureto evisible.涂料,油漆,乳液 旋轉(zhuǎn)流變儀的測量應(yīng)變或應(yīng)力的施加方穩(wěn)態(tài)測瞬態(tài)測動態(tài)測

通過施加瞬時改變的應(yīng)變（速率）或應(yīng)來測量流體的響應(yīng)隨時間對流體施加振蕩的應(yīng)變或響應(yīng)的應(yīng)力或應(yīng)穩(wěn)態(tài)

/Paa

需確定溫、掃描模（數(shù)、性或散測量延遲時、 、轉(zhuǎn)方等觸變對材料施加線性增大或減小的穩(wěn)態(tài)剪切瞬階躍應(yīng)力施加并維持一個瞬態(tài)形變（階躍應(yīng)變），測量維持這個應(yīng)變所需的應(yīng)力隨時間的變化。蠕給樣品施加恒定的應(yīng)力，測量樣品的應(yīng)變隨時間的變化動態(tài)測試方(體系形態(tài)結(jié)構(gòu)不受影響●●(對形態(tài)結(jié)構(gòu)的變化十分敏感 原理

固體(完全彈性)行為流體(完全變形)

完全彈性與完完全變形控制參測量結(jié)動態(tài)凝膠或熱固性頻率應(yīng)變等變時間多功能、積木式流變測量儀，通過記錄物料在混合過程中對轉(zhuǎn)子或螺桿產(chǎn)生的反扭矩以及溫度隨時間的變化，可研究物料在加工過程中的分散多功能、積木式流變測量儀，通過記錄物料在混合過程中對轉(zhuǎn)子或螺桿產(chǎn)生的反扭矩以及溫度隨時間的變化，可研究物料在加工過程中的分散交聯(lián)、熱穩(wěn)定性等）量控制的有效。Haake ThePolyLabSystemfromThermoHaakeusedtogetherwiththeRheomixmixersensorproducesrheogramsthatprovideproduction‐relatedinformationsuchas:dynamicviscositydependingontheshearload,meltbehaviorintheextruder,theinfluenceofadditives,andtemperatureandshearloadbehavior.

123 123rubberstonamea

平衡轉(zhuǎn)

ttMMBAexp0tMTTBBexp0 M(tt0)/M T§4.2.3Elongation曼法拉伸流熔體拉伸流變儀等應(yīng)變速率02v

v為輸送帶速e(t)

擠出拉伸流變儀熔體擠出速度夾棍拉伸速度拉伸拉伸速

v/v0(ln)/FeR2v(ln)/0潤滑擠拉溫拉絲流變儀NO.670熔體多軸拉伸流變儀ExtensionalMeissnerLimitedtoverylowstrainrates(<1s-1)MeltSpinningCanachievehigherstrainButdeformationisnotTheforcelevelwhenthebreaksiscalledthemeltUsefulnessofExtensionalExtensionalViscosityand“MeltStrength”arerelatedtotheperformanceofpolymersinprocessesinvolvingstretching,suchasfilmblowing,sheetextrusion,fiberspinning,blowmolding,thermoforming.IntheseprocessesahighmeltstrengthisdesirabletoensurethatthemeltcanbestretchedwithoutMeasurementoftensileimagesofthebreakupoffluidcolumnscomposedofsameoilwith500ppmofahighmolecularweightpolystyreneadditive(lowerimages).Theapproximatelocationofthelasermicro-meterisshownbythearrow.////

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WhatshouldyouNeedtodeterminetheshearviscosityifyouwanttodesigndies,determinepressuredrop,flowratesYouwillneedthefirstnormalstressdifferenceifyouhavewithswellingofYouwillneedstressrelaxationifyouworryaboutfrozen‐instressesinfinalproduct,orwarpageYouwillneedextensional(elongational)viscosityifyouusethepolymersforfiberspinning,filmblowingetc.Docreepexperimentsifyouareworriedaboutlongtermdimensional§4.3在日常工作中無處不在－制造和原材料通過加工（變形）制產(chǎn)品在外力性流變學(xué)流變學(xué)是實驗和實踐一般應(yīng)用的剪切速率§4.3.1旋轉(zhuǎn)流變儀的測量分子量及其分布的流變學(xué)方對高分子量尾端非常長支鏈（LCB）含量的斷液滴回小振幅動態(tài)剪切Palierne乳液Palierne乳液

G* 1M1H(4/R)(2G*5G*)(G*G*)(16G*H (40/R)(G*G*)(2G*3G*)(16G*

M-I-分散聚合直接擬合動態(tài)模 分散相多分散指數(shù)小于Palierne乳液由動態(tài)模量計算出松弛時間譜，分散相的體積平均半徑 4D 10(1)2(5 V (19