Preface: Novel Trends in Rheology VIII最新文献

{"title":"Nanostructures for air filtration. Filtration properties in range of maximum penetrating particle sizes","authors":"D. Kimmer, I. Vincent, Miroslava Kovarova, Lenka Lovecká","doi":"10.1063/1.5109516","DOIUrl":"https://doi.org/10.1063/1.5109516","url":null,"abstract":"End user customers and legislation of European countries require to classify the air filtration materials for ultra- fine particles separation in range of maximum penetrating particle size (MPPS). ...","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126057084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rheological characterization of starch-based biodegradable polymer blends","authors":"M. Nevoralová, Aleksandra Ujčić, Yadu Nath Vakkipurath Kodakkadan, Z. Starý","doi":"10.1063/1.5109511","DOIUrl":"https://doi.org/10.1063/1.5109511","url":null,"abstract":"Starch-based polymer blends are often investigated materials that attract great attention due to their disposition to combine advantageous properties of their components and ability to create materials with controlled biodegradation rate. In this contribution the rheological characterization of plasticized starch blended with biodegradable polyester poly (e-caprolactone) was carried out. For preparation of thermoplastic starch-based blends three different types of starches (wheat, corn and tapioca) were used. Two-step preparation process consisting of solution casting and melt mixing was performed and their rheological and thermomechanical behavior was analyzed. Moreover, morphological study on prepared blends was performed. Since the final properties of polymer blends depend directly on blend composition, the adjusting of the material components concentrations and using distinct processing procedures led to materials with various final morphologies and rheological properties as well. Different rheological behavior in the case of TPS (tapioca)/PCL blends compared to wheat or corn starch blended with PCL was observed. Whereas the latter two blends, as well as their neat starch components, exhibited gel-like behavior over the entire measured temperature range, tapioca starch/PCL blends behave as liquids at processing temperatures. The rheology findings about tapioca starch and its blends with polycaprolactone could be advantageously used for preparation of new starch-based polymer materials with controlled biodegradation and enhanced processability.Starch-based polymer blends are often investigated materials that attract great attention due to their disposition to combine advantageous properties of their components and ability to create materials with controlled biodegradation rate. In this contribution the rheological characterization of plasticized starch blended with biodegradable polyester poly (e-caprolactone) was carried out. For preparation of thermoplastic starch-based blends three different types of starches (wheat, corn and tapioca) were used. Two-step preparation process consisting of solution casting and melt mixing was performed and their rheological and thermomechanical behavior was analyzed. Moreover, morphological study on prepared blends was performed. Since the final properties of polymer blends depend directly on blend composition, the adjusting of the material components concentrations and using distinct processing procedures led to materials with various final morphologies and rheological properties as well. Different rheologica...","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"196 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134127902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rheology and structure of immiscible polymer blends filled with carbon black","authors":"Z. Starý, M. Nevoralová, Valentina Dragčević","doi":"10.1063/1.5109510","DOIUrl":"https://doi.org/10.1063/1.5109510","url":null,"abstract":"In this contribution immiscible polystyrene/polymethylmethacrylate (PS/PMMA) blends filled with carbon black (CB) are investigated in a broad composition range. In these blends carbon black is localized preferentially in polystyrene phase. The influence of carbon black on blends phase structure is evaluated and consequently rheology and electrical conductivity is discussed. Pronounced differences in the morphology of unfilled and filled blends were observed in cases, in which PS phase containing CB forms a minor phase. Dispersed morphology with spherical particles and sharp interfaces turned by addition of 3 vol.% of CB into partially co-continuous morphology with irregular domain shapes. This morphology change was detected even in blends with PS content as low as 10 vol.%. The rheology of the blends was largely influenced by the addition of CB in the systems with PS matrix.","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117253084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuum mechanics of shear stress growth","authors":"C. Saengow, A. J. Giacomin","doi":"10.1063/1.5109494","DOIUrl":"https://doi.org/10.1063/1.5109494","url":null,"abstract":"One good way to explore fluid microstructure experimentally is to suddenly subject the fluid to a large steady shearing deformation, and to then observe the evolving stress response. If the steady shear rate is high enough, the shear stress and also the normal stress differences can, overshoot, and then, they can even undershoot. We call such responses nonlinear, and this experiment shear stress growth. This work discusses exact analytical solutions for interpreting measured nonlinear shear stress growth responses from the Oldroyd 8-constant constitutive framework. Specifically, we explore the effect of η∞ on stress growth material functions using the special case of the corotational Jeffreys fluid. Using the Johnson-Segalman fluid, we also explore the effect of non-affine deformation. Lastly, we explore the role played by three nonlinear Oldroyd parameters (µ0, ν1, ν2).One good way to explore fluid microstructure experimentally is to suddenly subject the fluid to a large steady shearing deformation, and to then observe the evolving stress response. If the steady shear rate is high enough, the shear stress and also the normal stress differences can, overshoot, and then, they can even undershoot. We call such responses nonlinear, and this experiment shear stress growth. This work discusses exact analytical solutions for interpreting measured nonlinear shear stress growth responses from the Oldroyd 8-constant constitutive framework. Specifically, we explore the effect of η∞ on stress growth material functions using the special case of the corotational Jeffreys fluid. Using the Johnson-Segalman fluid, we also explore the effect of non-affine deformation. Lastly, we explore the role played by three nonlinear Oldroyd parameters (µ0, ν1, ν2).","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132183720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wall slip of highly filled powder injection moulding compounds in dependence on capillary die geometry","authors":"P. Filip, B. Hausnerova, Daniel Sanétrník, Eva Hnátková","doi":"10.1063/1.5109499","DOIUrl":"https://doi.org/10.1063/1.5109499","url":null,"abstract":"The feedstocks used in Powder Injection Moulding (PIM) are formed by solid particles incorporated into a binder with presence of surfactant enabling manufacturing of highly concentrated suspensions. Relatively even distribution of particles is violated in the close vicinity of the walls. A thin layer adjacent to the walls is pre-dominantly occupied by the binder only and at the interface wall-binder so-called wall slip occurs. Success and acceptance of an injection moulding step in PIM process primarily subjects to this wall slip phenomenon. The wall slip was qualitatively and quantitatively measured using a capillary rheometer equipped with the dies of different entrance angles. It was proved that this differentness has a significant impact on an appearance of wall slip (its intensity). Using four PIM feedstocks reliable slip velocity values of highly filled compounds were obtained for conical dies contrasting to the results with flat dies used in the majority of studies.The feedstocks used in Powder Injection Moulding (PIM) are formed by solid particles incorporated into a binder with presence of surfactant enabling manufacturing of highly concentrated suspensions. Relatively even distribution of particles is violated in the close vicinity of the walls. A thin layer adjacent to the walls is pre-dominantly occupied by the binder only and at the interface wall-binder so-called wall slip occurs. Success and acceptance of an injection moulding step in PIM process primarily subjects to this wall slip phenomenon. The wall slip was qualitatively and quantitatively measured using a capillary rheometer equipped with the dies of different entrance angles. It was proved that this differentness has a significant impact on an appearance of wall slip (its intensity). Using four PIM feedstocks reliable slip velocity values of highly filled compounds were obtained for conical dies contrasting to the results with flat dies used in the majority of studies.","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132374911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of flow field on structure and properties for polycarbonate blends","authors":"M. Yamaguchi, Takumi Sako","doi":"10.1063/1.5109497","DOIUrl":"https://doi.org/10.1063/1.5109497","url":null,"abstract":"Flow-induced segregation and phase-mixing behaviors of polymer blends comprising polycarbonate (PC) and another polymer with low molecular weight, such as poly(methyl methacrylate) (PMMA) and polystyrene (PS), are studied. Although PMMA with low molecular weight is miscible with PC, the PMMA fraction in an injection-molded plate is found to be rich at the surface, suggesting that PMMA is segregated to the surface region under pressure-driven flow in the mold. The high concentration of the PMMA fraction at surface will provide enhanced surface hardness of a product. Furthermore, the PS addition is found to decrease the apparent shear viscosity greatly especially in the high shear rate region at capillary extrusion, which will be responsible for a long spiral flow length at injection-molding. The decrease in the shear viscosity is attributed to the flow-induced phase-mixing, which occurs only in the surface region.Flow-induced segregation and phase-mixing behaviors of polymer blends comprising polycarbonate (PC) and another polymer with low molecular weight, such as poly(methyl methacrylate) (PMMA) and polystyrene (PS), are studied. Although PMMA with low molecular weight is miscible with PC, the PMMA fraction in an injection-molded plate is found to be rich at the surface, suggesting that PMMA is segregated to the surface region under pressure-driven flow in the mold. The high concentration of the PMMA fraction at surface will provide enhanced surface hardness of a product. Furthermore, the PS addition is found to decrease the apparent shear viscosity greatly especially in the high shear rate region at capillary extrusion, which will be responsible for a long spiral flow length at injection-molding. The decrease in the shear viscosity is attributed to the flow-induced phase-mixing, which occurs only in the surface region.","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129015379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of heat transfer coefficient on crystalline phase development during production of casted film","authors":"Tomas Barborik, M. Zatloukal","doi":"10.1063/1.5109501","DOIUrl":"https://doi.org/10.1063/1.5109501","url":null,"abstract":"In this study, the stable numerical scheme has been developed for non-isothermal 1.5D film casting model of Silagy et al. (Polym Eng Sci 36:2614-2625, 1996) utilizing viscoelastic modified Leonov model as the constitutive equation and energy equation coupled with crystallization kinetics of semicrystalline polymers considering actual temperature as well as a cooling rate. In the proposed model, forced and natural convection together with a heat radiation emitting from the film surface is considered to model the heat transfer. Model has been successfully validated on the experimental data for linear isotactic polypropylene taken from the open literature. In this work, effect of the forced convection on the neck-in phenomenon (unwanted film width shrinkage during stretching in the post die area) and crystalline phase development during a flat film production was systematically investigated. It is believed that the utilized numerical model together with suggested stable numerical scheme as well as obtained research results can help to more thoroughly understand the processing window for production of flat porous membranes from linear iPP considerably.In this study, the stable numerical scheme has been developed for non-isothermal 1.5D film casting model of Silagy et al. (Polym Eng Sci 36:2614-2625, 1996) utilizing viscoelastic modified Leonov model as the constitutive equation and energy equation coupled with crystallization kinetics of semicrystalline polymers considering actual temperature as well as a cooling rate. In the proposed model, forced and natural convection together with a heat radiation emitting from the film surface is considered to model the heat transfer. Model has been successfully validated on the experimental data for linear isotactic polypropylene taken from the open literature. In this work, effect of the forced convection on the neck-in phenomenon (unwanted film width shrinkage during stretching in the post die area) and crystalline phase development during a flat film production was systematically investigated. It is believed that the utilized numerical model together with suggested stable numerical scheme as well as obtained r...","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130376812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D-printing quality in relation to melt flow and fusion behavior of polymer materials","authors":"D. Auhl, Falk Rohnstock, Oliver Löschke, K. Schäfer, Peng Wang, M. Wagner","doi":"10.1063/1.5109498","DOIUrl":"https://doi.org/10.1063/1.5109498","url":null,"abstract":"Full fusion and layer contact are essential for the mechanical, but also optical quality of 3D-printed parts. A comprehensive study on relations of 3D-printing quality to melt flow and fusion behavior is presented for a wide range of thermoplastic polymer materials. We investigated the influence of polymer structure and chain length as well as processing temperature, which largely determine material viscosity and surface tension. Furthermore, the influence of particle or layer dimensions is investigated. Comparisons of experimental and simulated data using well-established models and sets of parameters allow drawing valuable conclusions for optimizations of 3D-printing conditions and product quality.Full fusion and layer contact are essential for the mechanical, but also optical quality of 3D-printed parts. A comprehensive study on relations of 3D-printing quality to melt flow and fusion behavior is presented for a wide range of thermoplastic polymer materials. We investigated the influence of polymer structure and chain length as well as processing temperature, which largely determine material viscosity and surface tension. Furthermore, the influence of particle or layer dimensions is investigated. Comparisons of experimental and simulated data using well-established models and sets of parameters allow drawing valuable conclusions for optimizations of 3D-printing conditions and product quality.","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130638229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elastic behavior and processing of polymer melts","authors":"H. Münstedt","doi":"10.1063/1.5109495","DOIUrl":"https://doi.org/10.1063/1.5109495","url":null,"abstract":"Whereas the influence of viscous properties of a polymer melt on some aspects of processing has widely been reported in the literature, investigations with respect to elastic properties are rare. In this paper effects of the elastic behavior on processing and those of processing on molecular orientation and recoverable strain are presented. As elastic property the role of extrudate swell in its many facets is discussed. Experiments on cast film extrusion are described and their results discussed as a function of the Deborah number, which is often used as a quantity for the elasticity at short processing times. Film contours and resonance frequencies are presented in detail. With respect to the influence of processing on properties of manufactured items results from the literature are discussed, which show that one has to distinguish between effects on the orientation of molecule segments and on the recoverable strain. The role of non-uniform distributions of the recoverable strain within a manufactured sample for its properties is shortly addressed.Whereas the influence of viscous properties of a polymer melt on some aspects of processing has widely been reported in the literature, investigations with respect to elastic properties are rare. In this paper effects of the elastic behavior on processing and those of processing on molecular orientation and recoverable strain are presented. As elastic property the role of extrudate swell in its many facets is discussed. Experiments on cast film extrusion are described and their results discussed as a function of the Deborah number, which is often used as a quantity for the elasticity at short processing times. Film contours and resonance frequencies are presented in detail. With respect to the influence of processing on properties of manufactured items results from the literature are discussed, which show that one has to distinguish between effects on the orientation of molecule segments and on the recoverable strain. The role of non-uniform distributions of the recoverable strain within a manufactured sa...","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123724048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of percolated network at the linear - Nonlinear transition in oscillatory shear","authors":"K. Gaska, Roland Kádár","doi":"10.1063/1.5109509","DOIUrl":"https://doi.org/10.1063/1.5109509","url":null,"abstract":"In this publication we review evidence for the detection of a percolated network in polymer nanocomposites at the linear - nonlinear transition in oscillatory shear tests. Two types of nanocomposites based on branched polymers as matrix are compared: a low density polyethylene (LDPE) and graphite nanoplatelets (GnP) as filler and a poly(ethylene- butyl acrylate) (EBA) containing graphite nanoplatelets and carbon black (CB). Oscillatory shear tests were analyzed in the framework of Fourier-transform rheology and Tschebyshev polynomial decomposition. For both nanocomposites, in the vicinity of the electrical percolation threshold, i.e. the formation of a continuous filler network, a distinct region is evidence at the transition linear - nonlinear transition in the strain dependent third relative higher harmonics of the shear stress Fourier spectra. The region can be characterized by different strain amplitude dependence that could be related to the specific filler morphologies, however, further investigations are required to assess the factors that influence the linear - nonlinear transition region in polymer nanocomposites.","PeriodicalId":378117,"journal":{"name":"Preface: Novel Trends in Rheology VIII","volume":"6 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115382925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}