Rheologica Acta最新文献

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Measurement of microscopic rheological properties in oil-in-water emulsions via spherical nanoindentation 通过球形纳米压痕测量水包油型乳液的微观流变特性
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-09-13 DOI: 10.1007/s00397-023-01415-x
Yunosuke Kimoto, Machi Horiai, Satoshi Nagase, Akira Uno, Yasunori Sato, Tsutomu Takahashi
{"title":"Measurement of microscopic rheological properties in oil-in-water emulsions via spherical nanoindentation","authors":"Yunosuke Kimoto,&nbsp;Machi Horiai,&nbsp;Satoshi Nagase,&nbsp;Akira Uno,&nbsp;Yasunori Sato,&nbsp;Tsutomu Takahashi","doi":"10.1007/s00397-023-01415-x","DOIUrl":"10.1007/s00397-023-01415-x","url":null,"abstract":"<div><p>Techniques for evaluating the micromechanical properties of materials are crucial in engineering fields. In previous studies, many researchers have utilized atomic force microscopy (AFM) to address these subjects. However, there are few data on dispersion systems, such as slurries and creams, due to the AFM tip having a nanoscale length. These materials are essential in industrial and engineering settings, requiring an accurate evaluation in a manner similar to AFM. Hence, we focus on ultrahigh accuracy and sensitive spherical nanoindentation (SNI), allowing the measurement of tissue-level features at the surface layer to characterize this soft matter. In this study, we show that SNI potentially measures the local spatial properties of concentrated dispersion fluids, especially oil-in-water (O/W) emulsions with various multilamellar structures. We set the parameter <i>t</i><sub>e</sub> for considering the organization of an equilibrium state consisting of the energy release rate and the work of adhesion on the Johnson–Kendall–Roberts (JKR) predictions. An important consequence of introducing <i>t</i><sub>e</sub> is that the results obtained by SNI match the theoretical JKR values for large <i>t</i><sub>e</sub>, suggesting that we can evaluate the microscopic properties more accurately using the classical JKR model. We find that the local features are affected by the lamellar bilayers and the work of adhesion Δ<i>γ</i> grows monotonically with increases in space occupied by lamellar structures. Since viscosity effects, such as mechanical energy dissipation and interpenetration, appear as a part of Δ<i>γ</i>, the behavior of Δ<i>γ</i> clearly shows the microscopic characteristics of the O/W emulsions.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 11-12","pages":"631 - 640"},"PeriodicalIF":2.3,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135690675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Anticipating gelation and vitrification with medium amplitude parallel superposition (MAPS) rheology and artificial neural networks 用中振幅平行叠加(MAPS)流变学和人工神经网络预测凝胶化和玻璃化
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-09-11 DOI: 10.1007/s00397-023-01407-x
Kyle R. Lennon, Joshua David John Rathinaraj, Miguel A. Gonzalez Cadena, Ashok Santra, Gareth H. McKinley, James W. Swan
{"title":"Anticipating gelation and vitrification with medium amplitude parallel superposition (MAPS) rheology and artificial neural networks","authors":"Kyle R. Lennon,&nbsp;Joshua David John Rathinaraj,&nbsp;Miguel A. Gonzalez Cadena,&nbsp;Ashok Santra,&nbsp;Gareth H. McKinley,&nbsp;James W. Swan","doi":"10.1007/s00397-023-01407-x","DOIUrl":"10.1007/s00397-023-01407-x","url":null,"abstract":"<div><p>Anticipating qualitative changes in the rheological response of complex fluids (e.g., a gelation or vitrification transition) is an important capability for processing operations that utilize such materials in real-world environments. One class of complex fluids that exhibits distinct rheological states are soft glassy materials such as colloidal gels and clay dispersions, which can be well characterized by the soft glassy rheology (SGR) model. We first solve the model equations for the time-dependent, weakly nonlinear response of the SGR model. With this analytical solution, we show that the weak nonlinearities measured via medium amplitude parallel superposition (MAPS) rheology can be used to anticipate the rheological aging transitions in the linear response of soft glassy materials. This is a rheological version of a technique called structural health monitoring used widely in civil and aerospace engineering. We design and train artificial neural networks (ANNs) that are capable of quickly inferring the parameters of the SGR model from the results of sequential MAPS experiments. The combination of these data-rich experiments and machine learning tools to provide a surrogate for computationally expensive viscoelastic constitutive equations allows for rapid experimental characterization of the rheological state of soft glassy materials. We apply this technique to an aging dispersion of Laponite<sup>®</sup> clay particles approaching the gel point and demonstrate that a trained ANN can provide real-time detection of transitions in the nonlinear response well in advance of incipient changes in the linear viscoelastic response of the system.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 10","pages":"535 - 556"},"PeriodicalIF":2.3,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01407-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135936126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Scattering-Informed Microstructure Prediction during Lagrangian Evolution (SIMPLE)—a data-driven framework for modeling complex fluids in flow 拉格朗日演化过程中散射信息的微观结构预测(SIMPLE)是一种数据驱动的复杂流体流动建模框架
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-09-09 DOI: 10.1007/s00397-023-01412-0
Charles D. Young, Patrick T. Corona, Anukta Datta, Matthew E. Helgeson, Michael D. Graham
{"title":"Scattering-Informed Microstructure Prediction during Lagrangian Evolution (SIMPLE)—a data-driven framework for modeling complex fluids in flow","authors":"Charles D. Young,&nbsp;Patrick T. Corona,&nbsp;Anukta Datta,&nbsp;Matthew E. Helgeson,&nbsp;Michael D. Graham","doi":"10.1007/s00397-023-01412-0","DOIUrl":"10.1007/s00397-023-01412-0","url":null,"abstract":"<div><p>An overarching challenge in rheology is to develop constitutive models for complex fluids for which we lack accurate first principles theory. A further challenge is that most experiments probing dynamical structure and rheology do so only in very simple flow fields that are not characteristic of the complex deformation histories experienced by material in a processing application. A recently developed experimental methodology holds potential to overcome this challenge by incorporating a fluidic four-roll mill (FFoRM) into scanning small-angle X-ray scattering instrumentation (sSAXS) (Corona, P. T. et al. <i>Sci. Rep.</i> <b>8</b>, 15559 (2018); Corona, P. T. et al. <i>Phys. Rev. Mater</i> <b>6</b>, 045603 (2022)) to rapidly generate large data sets of scattering intensity for complex fluids along diverse Lagrangian flow histories. To exploit this uniquely rich FFoRM-sSAXS data, we propose a machine learning framework, <i>Scattering-Informed Microstructure Prediction under Lagrangian Evolution</i> (SIMPLE), which uses FFoRM-sSAXS data to learn an evolution equation for the scattering intensity and an associated tensorial differential constitutive equation for the stress. The framework incorporates material frame indifference and invariance to arbitrary rotations by data preprocessing. We use autoencoders to find an efficient reduced order model for the scattering intensity and neural network ordinary differential equations to predict the time evolution of the model coordinates. The framework is validated on a synthetic FFoRM-sSAXS data set for a dilute rigid rod suspension. The model accurately predicts microstructural evolution and rheology for flows that differ significantly from those used in training. SIMPLE is compatible with but does not require material-specific constraints or assumptions.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 10","pages":"587 - 604"},"PeriodicalIF":2.3,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01412-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136107293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Fractional rheology-informed neural networks for data-driven identification of viscoelastic constitutive models 基于分数流变学的神经网络用于粘弹性本构模型的数据驱动识别
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-08-26 DOI: 10.1007/s00397-023-01408-w
Donya Dabiri, Milad Saadat, Deepak Mangal, Safa Jamali
{"title":"Fractional rheology-informed neural networks for data-driven identification of viscoelastic constitutive models","authors":"Donya Dabiri,&nbsp;Milad Saadat,&nbsp;Deepak Mangal,&nbsp;Safa Jamali","doi":"10.1007/s00397-023-01408-w","DOIUrl":"10.1007/s00397-023-01408-w","url":null,"abstract":"<div><p>Developing constitutive models that can describe a complex fluid’s response to an applied stimulus has been one of the critical pursuits of rheologists. The complexity of the models typically goes hand-in-hand with that of the observed behaviors and can quickly become prohibitive depending on the choice of materials and/or flow protocols. Therefore, reducing the number of fitting parameters by seeking compact representations of those constitutive models can obviate extra experimentation to confine the parameter space. To this end, fractional derivatives in which the differential response of matter accepts non-integer orders have shown promise. Here, we develop neural networks that are informed by a series of different fractional constitutive models. These fractional rheology-informed neural networks (RhINNs) are then used to recover the relevant parameters (fractional derivative orders) of three fractional viscoelastic constitutive models, i.e., fractional Maxwell, Kelvin-Voigt, and Zener models. We find that for all three studied models, RhINNs recover the observed behavior accurately, although in some cases, the fractional derivative order is recovered with significant deviations from what is known as ground truth. This suggests that extra fractional elements are redundant when the material response is relatively simple. Therefore, choosing a fractional constitutive model for a given material response is contingent upon the response complexity, as fractional elements embody a wide range of transient material behaviors.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 10","pages":"557 - 568"},"PeriodicalIF":2.3,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01408-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46851262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Numerical investigation of rheological behaviors of polystyrene melts in different contraction dies based on the Rolie-Poly model 基于Rolie-Poly模型的聚苯乙烯熔体在不同收缩模内流变行为的数值研究
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-08-11 DOI: 10.1007/s00397-023-01410-2
Qingsheng Liu, Guixian Liu, Youqiong Liu, Chuntao Jiang
{"title":"Numerical investigation of rheological behaviors of polystyrene melts in different contraction dies based on the Rolie-Poly model","authors":"Qingsheng Liu,&nbsp;Guixian Liu,&nbsp;Youqiong Liu,&nbsp;Chuntao Jiang","doi":"10.1007/s00397-023-01410-2","DOIUrl":"10.1007/s00397-023-01410-2","url":null,"abstract":"<div><p>Extrusion molding is an important method in the polymer processing industry. The stress concentration of polymer melts can easily occur at the contraction channel, especially at the contraction exit during extrusion molding, which causes volume defects in the final parts. To eliminate or minimize volume defects, this study examined the effects of contraction profiles and contraction lengths on the rheological behaviors of polystyrene melts based on numerical methods and algorithms in the current study. The contraction profiles included abrupt contraction, V-shaped contraction, hyperbolic contraction, and elliptic contraction geometries at different contraction lengths. A single-mode Rolie-Poly model was employed to describe the stress–strain relationship of polystyrene melt. Additionally, the finite volume method and SIMPLE algorithm were used to discretize and solve the governing equations of the fluid in a 4:1 contraction flow. Numerical simulations of the principal stress difference (PSD), stretch ratio, and velocity of polystyrene melt in the aforementioned contraction geometries were implemented. The numerical results indicate that contraction profiles and contraction length are two major factors affecting the rheological behaviors of polystyrene melts in contraction flows based on the same contraction ratio and flow rate. V-shaped contraction, hyperbolic contraction, and elliptic contraction geometries can reduce stress concentration compared to abrupt contraction. Thus, during extrusion molding, it is better to use the elliptic contraction profile with adequate contraction length to eliminate or minimize defects in parts caused by stress concentration at the sharp edge exit.</p><h3>Graphical abstract</h3>\u0000 <figure><div><div><div><picture><source><img></source></picture></div></div></div></figure>\u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 9","pages":"417 - 432"},"PeriodicalIF":2.3,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4448412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Modeling elongational viscosity of polystyrene Pom-Pom/linear and Pom-Pom/star blends 模拟聚苯乙烯pompom /线状和pompom /星形共混物的伸长粘度
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-08-03 DOI: 10.1007/s00397-023-01411-1
Valerian Hirschberg, Shan Lyu, Max G. Schußmann, Manfred Wilhelm, Manfred H. Wagner
{"title":"Modeling elongational viscosity of polystyrene Pom-Pom/linear and Pom-Pom/star blends","authors":"Valerian Hirschberg,&nbsp;Shan Lyu,&nbsp;Max G. Schußmann,&nbsp;Manfred Wilhelm,&nbsp;Manfred H. Wagner","doi":"10.1007/s00397-023-01411-1","DOIUrl":"10.1007/s00397-023-01411-1","url":null,"abstract":"<div><p>The elongational rheology of blends of a polystyrene (PS) Pom-Pom with two linear polystyrenes was recently reported by Hirschberg et al. (J. Rheol. 2023, 67:403–415). The Pom-Pom PS280k-2x22-22k with a self-entangled backbone (<i>M</i><sub>w,bb</sub> = 280 kg/mol) and 22 entangled sidearms (<i>M</i><sub>w,a</sub> = 22 kg/mol) at each of the two branch points was blended at weight fractions from 75 to 2 wt% with two linear polystyrenes (PS) having <i>M</i><sub>w</sub> of 43 kg/mol (PS43k) and 90 kg/mol (PS90k), respectively. While the pure Pom-Pom shows strong strain hardening in elongational flow (SHF &gt; 100), strain hardening (SHF &gt; 10) is still observed in Pom-Pom/linear blends containing only 2 wt% of Pom-Pom. The elongational start-up viscosities of the blends with Pom-Pom weight fractions above 10 wt% are well described by the Molecular Stress Function (MSF) model, however, requiring two nonlinear fit parameters. Here we show that quantitative and parameter-free modeling of the elongational viscosity data is possible by the Hierarchical Multi-mode Molecular Stress Function (HMMSF) model based on the concepts of hierarchical relaxation and dynamic dilution. In addition, we investigated the elongational viscosity of a blend consisting of 20 wt% Pom-Pom PS280k-2x22-22k and 80 wt% of a PS star with 11 arms of <i>M</i><sub>w,a</sub> = 25 kg/mol having a similar span molecular weight as PS43k and similar <i>M</i><sub>w,a</sub> as the Pom-Pom. This work might open up possibilities toward polymer upcycling of less-defined polymers by adding a polymer with optimized topology to gain the intended strain hardening, e.g., for film blowing applications.</p><h3>Graphical Abstract</h3>\u0000 <figure><div><div><div><picture><source><img></source></picture></div></div></div></figure>\u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 9","pages":"433 - 445"},"PeriodicalIF":2.3,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01411-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4111938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Bidisperse magnetorheological fluids utilizing composite polypyrrole nanotubes/magnetite nanoparticles and carbonyl iron microspheres 利用复合聚吡咯纳米管/磁铁矿纳米颗粒和羰基铁微球的双分散磁流变流体
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-08-02 DOI: 10.1007/s00397-023-01409-9
Andrei Munteanu, Tomáš Plachý, Lenka Munteanu, Fahanwi Asabuwa Ngwabebhoh, Jaroslav Stejskal, Miroslava Trchová, Michal Kubík, Michal Sedlačík
{"title":"Bidisperse magnetorheological fluids utilizing composite polypyrrole nanotubes/magnetite nanoparticles and carbonyl iron microspheres","authors":"Andrei Munteanu,&nbsp;Tomáš Plachý,&nbsp;Lenka Munteanu,&nbsp;Fahanwi Asabuwa Ngwabebhoh,&nbsp;Jaroslav Stejskal,&nbsp;Miroslava Trchová,&nbsp;Michal Kubík,&nbsp;Michal Sedlačík","doi":"10.1007/s00397-023-01409-9","DOIUrl":"10.1007/s00397-023-01409-9","url":null,"abstract":"<div><p>Conductive polypyrrole nanotubes were synthesized with a two-step one-pot synthesis. During synthesis, the nanotubes were decorated with magnetite nanoparticles at different concentrations granting them magnetic properties. The characterization of the tubes revealed differences from the theoretical reactions. A bidisperse magnetorheological fluid (MRF) was prepared by mixing the composite polypyrrole nanotubes/magnetite nanoparticles with commercial carbonyl iron spherical microparticles in silicone oil. The rheological properties of the bidisperse system were studied under the presence of magnetic field at room and elevated temperature. An enhancement of the MR effect with the presence of the nanotubes was observed when compared with a standard MRF consisted only of magnetic microparticles. Due to the faster magnetic saturation of the nanotubes, this enhancement is exceptionally high at low magnetic fields. The stability of the system is studied under dynamic conditions where it is revealed that the nanotubes keep the standard particles well dispersed with the sedimentation improving by more than 50%.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 9","pages":"461 - 472"},"PeriodicalIF":2.3,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01409-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4071954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Data-driven constitutive model of complex fluids using recurrent neural networks 基于递归神经网络的复杂流体数据驱动本构模型
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-08-02 DOI: 10.1007/s00397-023-01405-z
Howon Jin, Sangwoong Yoon, Frank C. Park, Kyung Hyun Ahn
{"title":"Data-driven constitutive model of complex fluids using recurrent neural networks","authors":"Howon Jin,&nbsp;Sangwoong Yoon,&nbsp;Frank C. Park,&nbsp;Kyung Hyun Ahn","doi":"10.1007/s00397-023-01405-z","DOIUrl":"10.1007/s00397-023-01405-z","url":null,"abstract":"<div><p>This study introduces the Constitutive Neural Network (ConNN) model, a machine learning algorithm that accurately predicts the temporal response of complex fluids under specific deformations. The ConNN model utilizes a recurrent neural network architecture to capture the time dependent stress responses, and the recurrent units are specifically designed to reflect the characteristics of complex fluids (fading memory, finite elastic deformation, and relaxation spectrum), without presuming any equation of motion of the fluid. We demonstrate that the ConNN model can effectively replicate the temporal data generated by the Giesekus model and the Thixotropic-Elasto-Visco-Plastic (TEVP) fluid model under varying shear rates. To test the performance of the trained model, we subject it to an oscillatory shear flow, with periodic reversals in flow direction, which has not been trained on. The ConNN model successfully replicates the shear moduli of the original models, and the trained values of the recurrent parameters match the physical prediction of the original models. However, we do observe a slight deviation in the normal stresses, indicating that further improvements are necessary to achieve more rigorous physical symmetry and improve the model prediction.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 10","pages":"569 - 586"},"PeriodicalIF":2.3,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45637245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Various features of melt strain hardening of polymeric materials in uniaxial extension and their relation to molecular structure: review of experimental results and their interpretation 高分子材料在单轴拉伸中熔融应变硬化的各种特征及其与分子结构的关系:实验结果综述及其解释
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-07-25 DOI: 10.1007/s00397-023-01400-4
H. Münstedt
{"title":"Various features of melt strain hardening of polymeric materials in uniaxial extension and their relation to molecular structure: review of experimental results and their interpretation","authors":"H. Münstedt","doi":"10.1007/s00397-023-01400-4","DOIUrl":"10.1007/s00397-023-01400-4","url":null,"abstract":"<div><p>Strain hardening of polymer melts is able to improve the uniformity of items in processing operations with elongational deformation. Of particular interest in this aspect is the dependence of strain hardening on elongational rate. In its first part, the paper presents a review on melt strain hardening obtained in uniaxial extensional experiments. Its dependence on elongational rate is of particular interest insofar as besides non-strain-hardening polymers, strain hardening increasing or decreasing with rate can be found. Results on linear polymers like polystyrene (PS), polypropylene (PP), high-density polyethylene (HDPE), and linear low-density polylethylene (LLDPE) in dependence on molecular parameters are discussed, as well as those of various blends. Particularly interesting are the strain-hardening features of certain HDPEs and LLDPEs, which could be understood by the assumption of a non-homogeneous chemical structure of the samples. Blends of various compositions of a linear and a long-chain branched PP throw light on the complex relation between branching structure and rate dependence of strain hardening. In the second part of the paper, the different strain-hardening behavior of linear polymers is interpreted by assessing the Rouse times as decisive physical quantity. For blends of certain linear species like HDPE and PP and those of linear with long-chain branched polymers, the existence of separate phases in the molten state is postulated. The assumptions are discussed in the light of the various studies on miscibility of linear and branched polyolefins from the literature.</p><h3>Graphical Abstract</h3>\u0000 <figure><div><div><div><picture><source><img></source></picture></div></div></div></figure>\u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"62 7-8","pages":"333 - 363"},"PeriodicalIF":2.3,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-023-01400-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5346584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Influence of dispersion liquid and silica concentration on rheological properties of shear thickening fluids (STFs) 分散液和二氧化硅浓度对剪切增稠液流变性能的影响
IF 2.3 3区 工程技术
Rheologica Acta Pub Date : 2023-07-24 DOI: 10.1007/s00397-023-01406-y
Abdulhalim Aşkan, Mahmut Çapkurt, Emre Acar, Murat Aydın
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