Rheology and Application 流变学 流变仪及其应用

Transcription

1 美国 TA 仪器公司 Rheology and Application 流变学 流变仪及其应用 杨胜鹰 Simon Yang

2 研究材料的流动与变形

3 Non linear Flow Behavior 非线性流动行为 Pseudo-plastic

4 Elastic and viscous deformations 弹性和粘性变形 弹性 粘性 时间依存性 接触时间短 [< 1s] 长接触时间 [>1 hour]

5 Linear & Non-linear Behavior 线性和非线性行为 Linear flow regime 线性流动 Non linear behavior 非线性行为 Structure breaking

6 Non linear Flow Behavior 非线性流动行为 Flow induced structure Low viscosity at rest 流动诱发结构静置时低粘度

7 Flow and viscometry 流动与粘度计

8 Flow Viscometry 流动 - 粘度计 Time 施加速度 测量应力 stress rate <σ> Single point measurement of the viscosity 粘度的单点测试 <η> = <σ>/γ.

9 Typical Viscosity Values (Pa s) 典型的粘度值 (Pa s) Asphalt Binder 沥青混合料 -- Polymer Melt 聚合物熔体 --- Molasses 糖浆 Liquid Honey 蜂蜜 Glycerol 甘油 Olive Oil 橄榄油 Water 水 Air 空气 ,000 1, 需要对数坐标

10 Multi-step flow Viscometry 多步流动 - 粘度法 stress rate. <σ(γ)> Time... <η(γ)> = <σ(γ)>/γ Multi-point measureme nt of the viscosity.. <σ(γ)>. = flow curve <η(γ)> = viscosity curve

11 Types of Flow curves 流动曲线的分类 Bingham (Newtonian w/yield stress) Shear Stress, σ σ y Bingham Plastic (shear-thinning w/yield stress) Shear Thinning (Pseudoplastic) Newtonian Shear Thickening (Dilatent) Shear Rate, γ

12 Viscosity and flow curve models 粘度和流动曲线模型 Summary of Viscosity Models Newtonian σ = η γ Power law (Pseudoplastic) Power law (Dilatant) σ σ K γ n = ( n < 1) K γ n = ( n > 1) Bingham Casson Herschel-Bulkley σ = σ + y η γ p σ 2 = σ η 2 γ 2 c n σ = σ + y K γ

13 Thixotropic loop 触变环 up down Shear ramp up and down or thixotropic loop stress rate Time... η(γ) = σ(γ)/γ. σ(γ) The stress represents the instantaneous response to the applied rate. If the material is time dependent,

14 Thixotropic loop 触变环 100 Thixotropic loop for 3 Mayonnaise emulsions Thixotropic material Stress σ [Pa] sample A up sample A down sample B up sample B down sample C up sample C down Rate γ [1/s] Up and down ramps do not superpose Area under the curve is a measure of thixotropy

15 Stress ramp in stress controlled mode 应力扫描 Stress ramp stress deformation Time γ(t). η(σ) = σ/γ(σ) The stress is increase from zero to a finite value and the deformation is measured as a function of time. An instantaneous viscosity can be calculated from

16 Yield stress in a stress ramp 屈服应力 Viscosity η [Pas] Yield stress of a cosmetic lotion 4.0h[Pas] Yield stess (at maximum) = 5.4 Pa Strain Stress [Pa] Strain (x10-6) The maximum viscosity method is more representati ve and reproducibl e then the strain tangent method

17 Relaxation and oscillation 松弛和动态振荡测试

18 Silicone putty test 粘弹性材料测试 Whether the silicone putty behaves viscous or elastic depends on the time short long

19 Relaxation time 松弛时间 γ = γ sp + γ dp constant stress η γ =>σ(t)= σ o exp{-t/τ } with the relaxation time τ = η /G G(t)=G o exp{-t/ τ } t=0 time

20 Dynamic Mechanical Analysis 动态力学分析 time t G(t)=G o exp{-t/τ} Force ωτ G*(ω)=G o 1+ ω 2 τ 2 Period T ω = 1/2πT =1/t

21 Phase angle 相位角 The measured shift between the input wave and the output wave is called Phase angle δ The ratio between stress amplitude and strain amplitude is the Complex modulus 1.5 G* Stimulus (stress or strain) Response (strain or stress) phase angle, δ Angle

22 Viscoelastic Parameters 粘弹性参数 The modulus measured in a dynamic experiment is referred to as the complex modulus G* The complex modulus can be separated into two components: o An elastic component in phase with the strain. G' = G* cosδ. G' is the degree to which material behaves like an elastic solid and stores energy. o A viscous modulus in phase with the strain rate. G" = G* sinδ. G" is the degree to which material behaves like an ideal liquid and dissipates energy. G* = G + ig G /G = tan δ

23 Dynamic Mechanical Behavior 动态力学行为 η* = η G = ωη 10 4 t τ t obs = De η* = G/ω G = G De = 0 Liquid If the material time is shorter than the observation time De<1 (fluid behavior) G G η* De <<1 De=1 De>> De = Solid If the material time is longer than the observation time De>1 (solid behavior)

24 Non linear response 非线性响应

25 10 1 Non linear behaviour 非线性行为 1.0 G G γ>γ c 10 0 Tan δ γ c = 10 2 % Structure properties: If a structure is strained to its limits it will eventually break. Before breaking the structure will behave very non-linear. During this phase, higher harmonics become important

26 Rheological Characterization 流变性能表征 Rheology dynamic oscillation steady shearing FT-Rheology elongational flow FT γ& G und G = f( ) η und N 1 = f( γ& ) ( 3ω1 ) I( ω ) I 1 = f () γ H 0 = f( ε& ) linear regime non-linear regime, time-independent non-linear regime, time-dependent linear and nonlinear regime

27 Summary 小结 Flow and viscometry Pseudoplastic; Thixotropic; Yield; Dilatant Relaxation time and oscillation Concept of the relaxation time Separation of energy storage and dissipation Mechanical spectroscopy Material time and Observation time Deborah Non- linear behavior

28 Definition of Rheology Rheology is the science of flow and deformation of matter We use rheology to study fundamental relations, called constitutive relations, between forces and deformations in materials

29 Flow and Deformation Parameters: Shear Stress, Shear Strain, & Shear Rate Stress: Force per unit area. Symbol: σ Units: Pa (SI) or dyn/cm² (cgs) Shear Strain: Relative deformation in shear. Symbol: γ Units: None Shear Rate: Change of shear strain per unit time. Symbol: γ Units: s -1

30 Classical Extremes: Elasticity 1678: Robert Hooke develops his True Theory of Elasticity The power of any spring is in the same proportion with the tension therof. Hooke s Law: σ = Gγ or (stress = G x strain) where G is the RIGIDITY MODULUS Hooke s law describes ideal mechanical behavior using a constitutive equation in which stress and strain are related through a proportionality constant called the modulus G. If you double the stress, you double the strain.

31 Classical Extremes: Viscosity 1687: Isaac Newton addresses liquids and steady simple shearing flow in his Principia The resistance which arises from the lack of slipperiness of the parts of the liquid, other things being equal, is proportional to the velocity with which the parts of the liquid are separated from one another. Newton s Law: σ = ηγ where η is the Coefficient of Viscosity Newtons s law describes idea flow behavior using a constitutive equation in which stress and rate of strain are related through a proportionality constant called the viscosity. If you double the stress, you double the shear rate.

32 Linearity vs. Non-Linearity Hooke s and Newton s laws are linear laws. They assume direct proportionality between stress and strain, or shear rate no matter what the stress. Most materials we work with obey these laws over a limited range of stresses. Beyond this limited range a material behaves non-linearly.

33 Steady Simple Shearing Flow F = Force V = speed x o dx y x γ A = area y o Shear Stress: σ = F/A Strain: γ = dx/y o Shear Rate: γ = dγ/dt = V/y ο Viscosity: η = σ/γ

34 Terms and Units Flow Creep Oscillation F (N) 2 Area = A (m ) Height = x (m) v (ms ) -1 dx Shear Stress σ = F/A Shear Strain = dx / x γ. Shear Rate = v/ x Strain γ σ γ Solids Liquids Modulus G = / [Shear] Viscosity η = σ/ [For small Strains tan < ~ <] γ. γ

35 Geometry of Shear for Rotational Rheometers Cone & Plate Concentric Cylinders Plate & Plate Motor Applies Torque Strain read from Optical Encoder.

36 Gap Choice for Parallel Plate Geometry Set gap to be at least 10 x particle or droplet size [consider extremes of size distribution] Minimum gap should be 1000 microns 1) Set Gap & Trim Edge 2) Close microns Plate & Plate Plate & Plate

37 Cone and Plate Strain Constant: K γ = Stress Constant: K σ = 1 β 3 * G c π(r/10) 3 Fixed gap defined by cone angle and truncation Assortment of Plate Diameters Assortment of cone angles No velocity gradient from center to edge of plate during steady shear testing.

38 Cone Angles and Diameters Shear Stress 2cm 4cm 6cm Angle Shear Rate Decreases Increases

39 Limitations of Cone & Plate for Dispersions - Fixed Gap! Truncation Heights: 1 degree ~ microns 2 degrees ~ 60 microns 4 degrees ~ 120 microns Cone & Plate Truncation Height = Gap Gap must be > or = 10 [particle size]!!

40 Spring & Dashpot Models Elastic Deformation Viscous Flow Stress (σ) α Strain (γ) Stress (σ) α Strain. (γ). Rate γ γ σ Applied t σ Removed σ Applied t σ Removed

41 Models for Viscoelasticity γ Retardation Curve Relaxation Curve σ σ o Relaxation Curve σ Applied t σ Removed γ Applied

42 Creep Retardation Curve Compliance - J(t) (strain/stress) Burgers Model η 0 J 1 η 1 η 0 J 0 η J 1 1 Voigt Element J 0 t

43 Cone & Plate Geometry σ = 3M &γ 2πR 3 = ω α Torque MNm ω Rad/s Rm α Truncation

44 弹性 : 理想固体行为 储存变形能量的能力 变形后恢复原状的能力 变形与恢复瞬间发生, 没有时间滞后 可用 弹簧 模型表示 模量就是抵抗变形的能力, 多硬或多软 理想弹性固体遵循 Hook s Law

45 牛顿法则 : 理想流体法则 理想流体 ( 牛顿流体 ) 应力与剪切变形的关系是线性关系 理想粘性流体的粘度是常数, 没有剪切变稀或剪切增稠现象 τ = η δγ/δτ = ηŕ

46 理想流体与固体的行为特点 固体 - 完全弹性回复 τ 應力 γ 應變 G 模數 : F/A : Δx/H : τ/γ A: 施力面積 H: 高度 Δx: 移動距離 F: 施力 流体 - 完全流动变形 τ 應力 γ 應變 γ 應變率 η 稀稠度 : F/A : Δx/H : dγ/dt = V/H : τ/γ A: 施力面積 H: 液高 V: 流速 F: 施力

47 常用材料 ( 一般材料 ) 的行为描述 粘弹性体 - 部分回复 部份变形 Τ 应力 Γ 应变 Γ 应变率 : F/A : Δx/H : dγ/dt = V/H Δx: 位移距离 A: 施力面积 F: 施力 H: 高度 G 模量 η 稀稠度 : τ/γ 部分回复 : τ/γ 部分变形 如何描述其行為...

48 G 弹性模量 (τ /γ 0 ) : 弹性储存能量指标 G 粘性模量 (τ /γ 0 ): 变形消耗能量指标 G* 复模量 (Σ(G,G )) : 总变形能量指标 tanδ (G /G ) : 损耗因子 G* 总变形能量 G 变形损耗 G 弹性储存 tanδ 损耗因子

49 与时间有关的粘弹性行为 PDMS 的固体和液体特性 极短时间 [< 1s] 较长时间 [24 小时 ]

50 Viscoelasticity Defined Range of Material Behavior Solid Like Liquid Like Ideal Solid Most Materials Ideal Fluid Purely Elastic Viscoelastic Purely Viscous Viscoelasticity: Having both viscous and elastic properties

51 Linear Viscoelasticity Defined "If the deformation is small, or applied sufficiently slowly, the molecular arrangements are never far from equilibrium. The mechanical response is then just a reflection of dynamic processes at the molecular level which go on constantly, even for a system at equilibrium. This is the domain of LINEAR VISCOELASTICITY. The magnitudes of stress and strain are related linearly, and the behavior for any liquid is completely described by a single function of time." (Written by Bill Graessley, Princeton University) Reference: Mark, J.,et.al., Physical Properties of Polymers, American Chemical Society, 1984, p. 102.

52 Classical Extremes: Elasticity 1678: Robert Hooke develops his True Theory of Elasticity The power of any spring is in the same proportion with the tension therof. Hooke s Law: τ = Gγ or (stress = G x strain) where G is the RIGIDITY MODULUS Hooke s law describes ideal mechanical behavior using a constitutive equation in which stress and strain are related through a proportionality constant called the modulus G. If you double the stress, you double the strain.

53 Classical Extremes: Viscosity 1687: Isaac Newton addresses liquids and steady simple shearing flow in his Principia The resistance which arises from the lack of slipperiness of the parts of the liquid, other things being equal, is proportional to the velocity with which the parts of the liquid are separated from one another. Newton s Law: σ = ηγ where η is the Coefficient of Viscosity Newtons s law describes idea flow behavior using a constitutive equation in which stress and rate of strain are related through a proportionality constant called the viscosity. If you double the stress, you double the shear rate.

54 Response for Classical Extremes Spring Purely Elastic Response Dashpo t Purely Viscous Response Hookean Solid σ = Eε or τ = Gγ Newtonian. Liquid σ = ηγ In the case of the classical extremes, all that matters is the values of stress, strain, strain rate. The response is independent of the loading.

55 Linearity vs. Non-Linearity Hooke s and Newton s laws are linear laws. They assume direct proportionality between stress and strain, or shear rate no matter what the stress. Most materials we work with obey these laws over a limited range of stresses. Beyond this limited range a material behaves non-linearly.

56 DMA Viscoelastic Parameters: Damping, tan δ Dynamic measurement represented as a vector It can be seen here that G* = (G 2 +G 2 ) 1/2 G* Phase angle δ G' G" The tangent of the phase angle is the ratio of the loss modulus to the storage modulus. tan δ = G"/G' "TAN DELTA" (tan δ) is a measure of the damping ability of the material.

57 研究材料的流动与变形

58 流变学的研究范围 流动与变形行为与微观结构直接相关 橡胶条的拉伸与压缩, 轮胎橡胶接触面的回复 化妆品在皮肤上的涂抹及感觉, 牙膏的挤出特性及在牙刷上的稳定性 模具内部塑料热熔体的流动 涂料在墙面上的垂挂性 番茄酱的倾倒和稳定, 乳制品的特性 熔体纤维纺丝 涂料的涂装, 喷塑还是涂刷 胶粘剂的粘合 甚至山脉的流动!

59 流变学在日常工作中无处不在 - 制造和使用产品 原材料 通过加工 ( 变形 ) 制品 产品 在外力或变形下使用 性能 流变学是高分子学科的基础 流变学是实验和实践科学 Newton Einstein 与流变学 Rheology

60 流变学使生活更有趣 在我们日常的生活中, 通常用 软 硬 刚性 柔性 弹性 稠 薄 灵活性 来描述事物 流变学就是研究 软与硬 的科学 流变学应用领域 : 高分子材料 ( 热塑性, 热固性 ) 化妆品 洗涤用品 牙膏 食品 陶瓷浆料 轮胎 日常生活中不自觉地用到一些 流变 实验 - 手感

61 弹性 : 理想固体行为 储存变形能量的能力 变形后恢复原状的能力 变形与恢复瞬间发生, 没有时间滞后 可用 弹簧 模型表示 模量就是抵抗变形的能力, 多硬或多软 理想弹性固体遵循 Hook s Law

62 牛顿法则 : 理想流体法则 理想流体 ( 牛顿流体 ) 应力与剪切变形的关系是线性关系 理想粘性流体的粘度是常数, 没有剪切变稀或剪切增稠现象 τ = η δγ/δτ = ηŕ

63 理想流体与固体的行为特点 固体 - 完全弹性回复 τ 應力 γ 應變 G 模數 : F/A : Δx/H : τ/γ A: 施力面積 H: 高度 Δx: 移動距離 F: 施力 流体 - 完全流动变形 τ 應力 γ 應變 γ 應變率 η 稀稠度 : F/A : Δx/H : dγ/dt = V/H : τ/γ A: 施力面積 H: 液高 V: 流速 F: 施力

64 常用材料 ( 一般材料 ) 的行为描述 粘弹性体 - 部分回复 部份变形 Τ 应力 Γ 应变 Γ 应变率 : F/A : Δx/H : dγ/dt = V/H Δx: 位移距离 A: 施力面积 F: 施力 H: 高度 G 模量 η 稀稠度 : τ/γ 部分回复 : τ/γ 部分变形 如何描述其行為...

65 G 弹性模量 (τ /γ 0 ) : 弹性储存能量指标 G 粘性模量 (τ /γ 0 ): 变形消耗能量指标 G* 复模量 (Σ(G,G )) : 总变形能量指标 tanδ (G /G ) : 损耗因子 G* 总变形能量 G 变形损耗 G 弹性储存 tanδ 损耗因子

66 与时间有关的粘弹性行为 PDMS 的固体和液体特性 极短时间 [< 1s] 较长时间 [24 小时 ]

67 流变学中世界观与物性观的研发思维 世界观 : 由形变 温度与时间所组成 微观世界 : 分子结构的运动 温度与时间 宏观世界 : 应用环境的形变 温度与时间 宏观世界 温度 观察点 时间 ( 频率 ) 微观世界 形变

68 微观世界 : 分子结构的尺寸 温度与时间 松弛时间分布 τ γ τ β τ gg τ g τ α τ m 分子运动 温度变化 侧基运动主链运动结晶融熔流动 T γ Τ β Τ gg Τ g Τ α Τ m

69 小分子运动软链段运动自由链段运动动低运段典型流变分析图形 Log G, tanδ G tanδ 低高 温度频率 分子缠结硬链高

70 宏观世界 : 应用背景的形变 时间与温度 流动过程 剪切速率 沉淀 (Sediments) 10e-6 ~ 10e-4 垂挂 / 流平 (Sagging/Leveling) 10e-2 ~ 10e-1 管流 (Pipe Flow) 10 ~ 1000 混合 (Mixing) 10 ~ 1000 挤出 (Extrusion) 1 ~ 100 化妆品相关 从瓶中倒出 (Pouring from a bottle) 10e1 ~ 10e2 挤牙膏 (Extrusion of toothpaste from a tube) 10e2 擦护手霜 (application of hand lotions/creams) 10e2 ~ 10e4 涂口红, 指甲油 (Applying lipstick, nail polish) 10e3 ~ 10e4 喷雾 (Spraying aerosols) 10e3 ~ 10e5 粘合过程 粘合 (Tack) 10e-2 ~ 10e-1 键合 (Press Bonding) 10e-1 ~ 1 脱粘 (Peeling) 10e2 ~ 10e4 自动脱粘 (Auto-debonding) 10e-3 ~ 10e-2

71 变形方式 拉伸 tension 弯曲 Bending 剪切 Shear

72 AR 系列,ARES 系列 AR & ARES is available in many configurations, for a large variety of applications.

73 流变学原理简介 施加周期性变形 γ 固体 ( 完全弹性 ) 行为 τ*(t) Time γ (t) 流体 ( 完全变形 ) 行为 γ (t) Time τ*(t) 粘弹体行为 将粘弹性行为分割为完全弹性与完完全变形行为 τ 测量周期性应力 δ τ*(t) Time γ (t) τ (t) γ (t) Time τ (t)

74 控制参数 形变低形变属于线性行为范围 高形变属于非线性行为范围内 温度 频率 时间 低频相当于长时间行为高频相当于短时间行为 测量结果 G G Tanδ η

75 平行板夹具 间距可调 推荐 0.2 to 2.5 mm ( 根据样品的粘度 ) 可弃式平行板夹具 针对热固性材料 齿型平行板 针对易打滑样品

76 锥板 / 平行板夹具 测量材料范围 : 高分子熔体 流体 ( 悬浮液 / 乳液 ) 由锥度固定夹具间距 ; 在动态应变扫描或稳态应变扫描实验中没有速度的梯度 ; 等温实验 ;

77 同心圆筒夹具 材料材料范围 : 低粘度流体 有限稳定性的悬浮液 对应力敏感性材料的面积效应 装载过程中的加工历史

78 固体扭转夹具 应用范围 高模量固体样品 热固性材料 热塑性材料 弹性体

79 如何将动态数据与样品结构联系起来 PDMS FreqSweep 24 癈 L arg e r V ie w Stru cture Scale o r Size Sm alle r G" ( ) G' ( ) [Pa] [Pa] [Pa-s] Eta* ( ) Viscosity dom inates G'=G" Elasticity dom inates Freq [rad/s]

80 流变学与微观结构的关系

81 分散液的频率扫描 颗粒间无关联 颗粒间弱关联 log G, G, η* η G G log G, G, η* η G tan δ >>1 G tan δ = ~1 log ω log ω log G, G, η* 颗粒间强关联 η G G tan δ << 1 log ω

82 流变的本质 通过深入的了解材料的流变性能, 或者透彻的研究材料的微观结构, 就可以控制材料的性能 流变测试可以对制品的配方开发 工艺参数优化以及最终性能和解决问题都有指导性的帮助

83 流变的应用范围 高分子 / 塑料 / 熔体 弹性体 / 橡胶 热固性材料 涂料, 油墨, 涂层 食品 化妆品 / 日化

84 高分子 / 塑料 / 熔体 挤出 ( 如何获得较好的表面?) 流体表征 ( 充模完全吗?) 共混相容性 ( 混合的两相材料可以获得期望的性能吗?) 尺寸稳定性 ( 工件会坍塌吗?) 抗冲性 ( 冲撞时可以起到保护作用吗? )

85 弹性体与橡胶 冲击特性 ( 保险杠发生弯曲还是脆裂?) 玻璃化转变 ( 什么温度时变脆?) 阻尼特性 ( 这么点橡胶垫可以对我的 CD 唱机防震吗?)

86 热固性 固化时间 ( 为什么这批 5 分钟固化的环氧料需要 15 分钟?) 储藏期 ( 为什么这批 5 分钟固化的环氧料 1 分钟就变硬了?) 交联密度 ( 为什么还是这么粘?) 保质期 ( 还能用吗?) 强度 ( 头盔有多大的抗冲性?)

87 对涂料, 油墨, 涂层, 流变可以表征 : 涂刷性 ( 涂刷时方便吗?) 流平性 ( 刷痕会流平吗?) 垂挂性 ( 刷在墙壁上的涂料会流下来吗?) 印刷质量 ( 印刷时, 油墨是停留在印的地方, 还是散开来?) 高速印刷相容性 ( 油墨会堆在滚筒上吗?)

88 Case Study 1: 流变在高分子方面的应用 表征 MW, MWD; Branching; Filler/additives effects 加工性

89 流变曲线可以看出 HPDE 中 MFI 不能区别的信息

90 粘度与分子量的关系 : 低频时差别明显 HDPE MWD=2 Mw=1e5-1e7 at 190 C Eta* ( ) [P] w(m)*mw ( ) [ ] Mw [g/mol] Capillary test range at high shear MWD=2 Mw inceasing from 1e5 to 1e Freq [rad/s]

91 160 C 聚苯乙烯 PS MWD= Synthesized MW D PS MW D=2 Mw=1e4-1e6 at 160 癈 0.5 Eta* ( ) [P] w(m)*m w ( ) [ ] M w [g/m ol] Freq [rad/s]

92 零剪切粘度与分子量的关系

93 零剪切粘度法比 GPC 法更灵敏 Zero shear viscosity 3.4 power on Mw Eta ( ) [Pa-s] Intrinsic Viscosity 0.6 power on Mw Hidden Information Mw [g/mol]

94 不同分子量测定方法的比较 J.Rheol. 38(6), 1797(1994) 方法依存性灵敏度特点 GPC M 0.5 M -0.5 高分子量区域尺寸效应不明显 本征粘度 M 0.6 M -0.4 高分子量区域稀溶液理论很难成立 光散射 M 1 M 0 高分子量区域敏感 渗透压 M -1 M -2 低分子量的数均分子量较好 零剪切粘度 M 3.4 M 2.4 高分子量区域灵敏度最高 回复柔量 (Mz/Mw) 3.5. 分子量分布最敏感, 对分子量不敏感

95 分子量宽度对流变性能的影响

96 支化对流变性能的影响

97 长链支化对流变性能的影响

98 快速质量控制 : 交叉点与分子量 分子量分布的关系 HDPE FreqSweep 190 C 10 6 Narrow MWD 10 5 G" ( ) [Pa] G' ( ) [Pa] 10 4 High Mw Broad MWD Low Mw 10 3 For linear PP at 200 C (study of Hercules), MWD= Mw/Mn = 10e6(dynes/cmq)/Gc Ln Eta(0) = ln Mw ln Mw/Mn Freq [rad/s]

99 支化的效果 HDPE Freq sweepat 190 癈 G' ( ) [Pa] 10 3 [Pa-s] Eta* ( ) Inceasing long Branching G' PE1 Linear PE2 f ew long branching PE 3 more long branching Freq [rad/s] 10 2

100 PE 长链支化度的测定

101 支化链与线性链

102 剪切与拉伸

103 拉伸过程中的线性链与支化链

104 熔体频率扫描与微观结构 加工性的关系 (1) 零剪切粘度与分子量 Mw 相关 (2) 粘度曲线形状可以检测分子量分布 MWD, 长短链支化 ; 加工粘度估算 (3) 口模膨胀速率与损耗模量 G 有关 (4) 口模膨胀大小与弹性模量 G 有关 ; 若与零剪切粘度结合, 可以评价熔体强度.

105 高分子加工过程中的流变学

106 影响高分子粘度的因素

107 共混对流变性能的影响

108 Case Study 2 聚合物溶液

109 高分子溶液浓度对粘度的影响 Eta N A Ps 26ppm Steady R ate Sweep 25 癈 N A Ps 53ppm Steady R ate Sweep 25 癈 N A Ps 114ppm Steady R ate Sweep 25 癈 N A Ps 332ppm Steady R ate Sweep 25 癈 N A Ps 690ppm Steady R ate Sweep 25 癈 N A Ps 1663ppm Steady R ate Sweep 25 癈 N A Ps 2300ppm Steady R ate Sweep 25 癈 N A Ps 3548ppm Steady R ate Sweep 25 癈 Eta ( ) [P] Increasing Polym er concentration Rate [s -1 ]

110 零剪切粘度与浓度的关系 Eta(0) ( ) [P] Eta(10) ( ) [P] Eta(100) ( ) [P] 10-2 C* c [%]

111 弹性与损耗模量与浓度的关系 G" ( ) [dyn/cm 2 ] G' ( ) [dyn/cm 2 ] Inc re a s ing c onc e ntration P olym e r c ha ins ov e rla p a nd form e nta ngle m e nts G' Freq [rad/s] W/W % NAPs 114ppm Freq Sweep 25 癈 NAPs 911ppm Freq Sweep 25 癈 NAPs 1663ppm Freq Sweep 25 癈 NAPs 188ppm Freq Sweep 25 癈 NAPs 690ppm Freq Sweep 25 癈 NAPs 3548ppm Freq Sweep 25 癈

112 HPAM 与新配高分子体系 (1% : 0.09%) 的粘度比较 10 1 Eta NAPS 0.09% Steady Stress Sweep 29C HPAM 0.09% Steady Rate Sweep 29C 10 0 Eta ( ) [Pa-s ] Hidden Inf orm ation R a te [s -1 ]

113 HPAM 与新配高分子体系 (2% : 0.3%) 的粘度比较 10 2 Eta N APS 0.3% Steady Stress Sweep 28C H PAM 0.3% Steady Stress Sweep 28C 10 1 Eta ( ) [Pa-s ] R a te [s -1 ]

114 HPAM 与新配高分子体系 (3% : 0.3%) 的粘弹性比较 10 1 G' NAPS 0.3% solution FreqSw eep 25C ARES HP A M so lut ion 0.3 % Fr e qs w e ep 25C A RES G" ( ) [Pa] G' ( ) [Pa] 10 0 Dynamic Test Indicates that NAPS forms a bigger structure Fr eq [ra d/s ]

115 法向力与弹性模量的关系

116 检测固化过程 ( 最小粘度 凝胶点 )

117 利用多波模式精确测量树脂固化的凝胶点

118 一种热固性树脂固化的周期 ( 固化过程中施加一定的压力, 降低气泡成核 )

119 水汽对环氧固化的影响

120 粘度与温度的依存性可作为判断优劣的根据

121 配方优化

122 添加硬脂酸锌降低注射时树脂粘度, 但不影响固化时间

123 工艺条件优化

124 B 阶段对环氧粘度的影响

125 最低粘度对制品性能影响

126 GE 硅橡胶的硫化 Curing of GE Slicone Rubber G" ( ) [Pa] G' ( ) [Pa] Temp ( ) [ C] time [s]

127 不同加热速率下的固化 EME6300H TempRamp 癈 1Hz 5 癈 min G' ( ) [dyn/cm 2 ] G' EME6300H TempRamp 癈 1Hz 5 癈 min-1 EME6300H TempRamp 癈 1Hz 40 癈 min-1 EME6300H TempRamp 癈 1Hz 20 癈 min-1 EME6300H TempRamp 癈 1Hz 10 癈 min time [s]

128 结构胶粘剂的固化 Tra-Bond F G" ( ) [dyn/cm 2 ] G' ( ) [dyn/cm 2 ] Temp ( ) [ C] x x10 4 time [s]

129 讨论 粘度太低 - 不能控制孔穴填充 粘度太高 - 空洞或填充不完全 G 太高 - Wire Sweep & Stresses. 水汽吸附 - 空洞 较快的凝胶点 - 产生应力 & 不完全 孔穴填充

130 Case Study 4: 各种材料的流变性能 流变性能 粘度与流动 模量与弹性

131 水的流变性能

132 低粘度聚合物溶液 灵敏度和重现性都很好

133 Coffee 奶末的频率扫描实验

134 在流变仪上进行丙烯酸共混物的实验结果

135 油墨的流动性 : 粘度与剪切速率的关系

136 塑料溶胶的平衡粘度曲线 并非每一种材料都是剪切变稀的

137 通过粘度检测 MW 和 MWD 的区别

138 流变曲线可以看出 HPDE 中 MFI 不能区别的信息

139 油脂的屈服应力

140 通过蠕变测量油脂在 25 C 的屈服应力

141 汽车涂料样品 : 应力扫描

142 结构与性能的关系 结晶度 分子量和交联对模量的影响

143 Food Characterization by Rheology Study of flow and deformation vital to production of quality food products

144 Flow Curves: Shear Thinning Fluids η, Pa.s γ,1/s η, Pa.s σ, Pa σ, Pa Ideal Yield Stress (Bingham plastic) γ,1/s

145 Newtonian & Shear Thinning Samples viscosity (Pa.s) Xanthan/Gellan Fructose Soln. N450, S E E E shear rate (1/s) 1000

146 Mathematical Curve Modeling Summary of Viscosity Models σ = η γ Newtonian Pseudoplastic Dilatant σ σ K γ n = ( n < 1) K γ n = ( n > 1) Bingham Casson Herschel-Bulkley σ = σ + y η γ p σ 2 = σ η 2 γ 2 c n σ = σ + y K γ

147 Milk: Equilibrium Flow Curves Low Fat viscosity (Pa.s) Full Fat E shear rate (1/s) 10000

148 Flow Curve for an Elastic Drink Equilibrium Flow of Elastic Drink TA Instruments viscosity (Pa.s) Region of "Apparent Yield Stress" >>>> shear rate (1/s) E E E E shear stress (Pa) 1.000E

149 Creep Curves for Chocolate Milk compliance (m^2/n) Stress = 0.3, 0.4 & 0.5 Pa 0.5 Pa 0.3 and 0.4 Pa Linear Viscoelastic Region Exceeded when stress > 0.4 Pa 1.0E time (s) 250.0

150 Solidification: Temperature Sweep Butter BLEND.20O-temperature ramp BUTTER.20O-Oscillation step MARG.22O-temperature ramp G' (Pa) /60 Blend Margarine temperature (Deg C) 25.0

151 Stability is Structure Related Structured Fluids Oscillation Stress 6.28 rad / sec 1000 G' (Pa) osc. stress (Pa) 100.0

152 Idealized Full Flow Curve - Polymers Power Law Region First Newtonian Plateau η 0 = Zero Shear Viscosity η 0 = K x MW c 3.4 Measure in Flow Mode on AR1000/AR500 Extend Range with Time- Temperature Superposition (TTS) & Cox-Merz Extend Range with Oscillation & Cox-Merz Molecular Structure Compression Molding Extrusion Blow and Injection Molding 1.00E E E E4 1.00E5 shear rate (1/s)