An Approach to Chemorheology of a Filled SBR Compound

1999 ◽  
Vol 72 (2) ◽  
pp. 361-383 ◽  
Author(s):  
R. Ding ◽  
A. I. Leonov
Keyword(s):  
Kinetic Studies ◽  
Rheological Parameters ◽  
Cross Linking ◽  
Rheological Characterization ◽  
Degree Of Cure ◽  
Unique Possibility ◽  
Rubber Compounds ◽  
Filled Rubbers ◽  
Basic Experiments

Abstract Three steps in complex chemorheological studies are necessary for complete rheological characterization of filled rubbers during cross-linking reaction. They include: (i) kinetic studies of cross-linking reaction, (ii) rheological studies of green rubber compounds, and (iii) correlation between the rheological parameters and the degree of cure. Basic experiments in the steps (i)–(iii) and their modeling are presented in this paper on the example of a filled SBR compound with sulfur accelerated vulcanization. The approach provides a unique possibility to trace therheological properties of rubber compounds from the green to completely cured states.

scholarly journals Toward Physicochemical and Rheological Characterization of Different Injectable Hyaluronic Acid Dermal Fillers Cross-Linked with Polyethylene Glycol Diglycidyl Ether

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 948
Author(s):  
Nicola Zerbinati ◽  
Sabrina Sommatis ◽  
Cristina Maccario ◽  
Maria Chiara Capillo ◽  
Giulia Grimaldi ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Polyethylene Glycol ◽  
Biological Activities ◽  
Diglycidyl Ether ◽  
Dermal Filler ◽  
Cross Linking ◽  
Matrix Structure ◽  
Dermal Fillers ◽  
Rheological Characterization

(1) Background: Injectable hyaluronic acid (HA) dermal fillers are used to restore volume, hydration and skin tone in aesthetic medicine. HA fillers differ from each other due to their cross-linking technologies, with the aim to increase mechanical and biological activities. One of the most recent and promising cross-linkers is polyethylene glycol diglycidyl ether (PEGDE), used by the company Matex Lab S.p.A., (Brindisi, Italy) to create the HA dermal filler PEGDE family. Over the last few years, several studies have been performed to investigate the biocompatibility and biodegradability of these formulations, but little information is available regarding their matrix structure, rheological and physicochemical properties related to their cross-linking technologies, the HA content or the degree of cross-linking. (2) Methods: Seven different injectable HA hydrogels were subjected to optical microscopic examination, cohesivity evaluation and rheological characterization in order to investigate their behavior. (3) Results: The analyzed cross-linked dermal fillers showed a fibrous “spiderweb-like” matrix structure, with each medical device presenting different and peculiar rheological features. Except for HA non cross-linked hydrogel 18 mg/mL, all showed an elastic and cohesive profile. (4) Conclusions: The comparative analysis with other literature works makes a preliminary characterization of these injectable medical devices possible.

The Rheological Characterization of the Writing Performance of Carbon Black Gel Ink

2009 ◽  
Vol 66 ◽  
pp. 139-142 ◽  
Author(s):  
Ji Jun Qian ◽  
Ai Ping Chen ◽  
Zhong Xin Liu ◽  
Chun Zhong Li
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Carbon Black ◽  
Rheological Parameters ◽  
Rheological Characterization ◽  
Writing Performance ◽  
Strong Shear ◽  
The Common ◽  
The Relationship

The rheological properties of carbon black gel ink were investigated by measurement the relationship between shear stress and shear rate. The fitting to the common rheological curve of gel ink with Hersegel-Bulkley equation was introduced. And the rheological parameters used to characterize the writing properties of gel ink were proposed. The results indicated that the gel ink system possessed strong shear-thinning ability. And the writing performance of the gel ink could be characterized with rheological parameters comprehensively.

scholarly journals Rheological Characterization of the Influence of Pomegranate Peel Extract Addition and Concentration in Chitosan and Gelatin Coatings

2021 ◽  
Vol 2 (3) ◽  
pp. 648-660
Author(s):  
Mirella Romanelli Vicente Bertolo ◽  
Rafael Leme ◽  
Virginia da Conceição Amaro Martins ◽  
Ana Maria de Guzzi Plepis ◽  
Stanislau Bogusz Junior
Keyword(s):  
Rheological Properties ◽  
Angular Frequency ◽  
Cross Linking ◽  
Rheological Characterization ◽  
Pomegranate Peel ◽  
All Solutions ◽  
Polymeric Solutions ◽  
Pomegranate Peel Extract ◽  
Peel Extract

In this study, the effects of an agro-industrial residue with active properties, pomegranate peel extract (PPE), were evaluated on the rheological properties of potential coatings based on chitosan (C) and gelatin (G). For this, rheological properties of the polymeric solutions were investigated in relation to PPE concentration (2 or 4 mg PPE g−1 solution), and to its incorporation order into the system (in C or in CG mixture). All solutions were more viscous than elastic (G″ > G′), and the change in PPE concentration had a greater influence accentuating the viscous character of the samples in which PPE was added to the CG mixture (CGPPE2 and CGPPE4). PPE addition to the CG mixture increased the angular frequency at the moduli crossover, indicating the formation of a more resistant polymeric network. This tendency was also observed in flow results, in which PPE addition decreased the pseudoplastic behavior of the solutions, due to a greater cross-linking between the polymers and the phenolic compounds. In general, all the studied solutions showed viscosities suitable for the proposed application, and it was possible to state the importance of standardizing the addition order of the components during the preparation of a coating.

scholarly journals Contribution to the rheological study of cementitious pastes with addition of residues from the processing of ornamental rocks

2018 ◽  
Vol 11 (6) ◽  
pp. 1284-1307 ◽  
Author(s):  
V. Y. SATO ◽  
A. P. L. GALINA ◽  
J. E. S. L. TEIXEIRA
Keyword(s):  
Rheological Parameters ◽  
Cement Matrix ◽  
Rheological Characterization ◽  
Cement Pastes ◽  
Rheological Study ◽  
Mineral Addition ◽  
Flow Test ◽  
Ornamental Stones ◽  
Thixotropic Fluid

Abstract Brazil is one of the world's largest producers and exporters in the field of ornamental stones. On the other hand, the production and processing of ornamental stones result in a large volume of unused material in the form of sludge, usually discarded inappropriately in sedimentation ponds or landfills. Several researches have been carried out aiming the reuse of this material in cementitious matrixes. In the field of rheology, there are still incipient national studies that use the rheological parameters obtained experimentally to determine the behavior of cement matrix based on Portland cement. Thus, the objective of this work is to characterize rheologically the behavior of cementitious pastes with and without addition of ornamental rock processing residue (RBRO) in its natural condition. Cement pastes were prepared with three a/c ratios (0.45, 0.55, 0.65) and four residue addition contents (0%, 5%, 10%, 15%) and submitted to the flow test. In tests for characterization of the residue, the RBRO presented as a material of specific fineness and mass near the cement, having low reactive activity, indicating that the residue can be used as an inert mineral addition in the cementitious matrix. In the rheological characterization tests of the pulps studied, it was observed in the flow tests that the samples behaved as a non-Newtonian, pseudoplastic and thixotropic fluid.

On the Filler Flocculation in Silica-Filled Rubbers Part I. Quantifying and Tracking the Filler Flocculation and Polymer-Filler Interactions in the Unvulcanized Rubber Compounds

2002 ◽  
Vol 75 (5) ◽  
pp. 865-890 ◽  
Author(s):  
Chenchy J. Lin ◽  
W. L. Hergenrother ◽  
E. Alexanian ◽  
G. G. A. Böhm
Keyword(s):  
Linear Regression Analysis ◽  
Quantitative Characterization ◽  
Polymer Filler ◽  
Rubber Compounds ◽  
On Line ◽  
Filled Rubbers ◽  
Dynamic Storage ◽  
Vulcanization Process ◽  
Flocculation Process

Abstract Filler flocculation was followed for silica filled compounds containing various alkoxy silanes and non-silane type polar additives. The methodology employed in this paper permitted a quantitative characterization of filler flocculation and polymer-filler interactions after heating the compound under conditions that simulated vulcanization. With the addition of trialkoxy silanes, the reduction of filler flocculation and the degree of polymer-filler interactions were found to depend on the type and the concentration of silane added, and on the mixing drop temperature (Td) used. Greater polymer-filler interactions and flocculation suppression were obtained with a compound containing a tetrasulfane when compared to that containing either a disulfane or a monofunctional-silane. Polar additives such as an amine compound and a sugar alcohol did not reduce the silica flocculation during simulated vulcanization because they were dewetted from the silica surface upon heating. The filler flocculation process was monitored by following the change of dynamic storage moduli using an on-line rheometer. The flocculation process order and process constant were extracted from the non-linear regression analysis of the kinetic data. These kinetic parameters were used to quantify the suppression of filler flocculation by the additives used. Filler flocculation was found not to be affected by the vulcanization process because it occurred prior to the onset of cure.

Better Process Description for the Extrusion of Silica and Carbon Black Compounds

2001 ◽  
Vol 74 (5) ◽  
pp. 899-914
Author(s):  
A. Limper ◽  
D. Schramm
Keyword(s):  
Carbon Black ◽  
Rheological Behavior ◽  
Extrusion Process ◽  
Rheological Characterization ◽  
Systematic Analysis ◽  
New Approach ◽  
Rubber Compounds ◽  
Plastics Processing ◽  
Multi Component System

Abstract In comparison to plastics processing, rubber processors handle a much more complex material. Due to active fillers used in rubber compounds, such as carbon black and silica, in some cases extraordinary filler/filler interactions occur. In general the multi-component system leads to a very complex rheological behavior. If silica compounds e.g. are processed the chemical modification of the filler surface (by organosilanes) has to be taken into account. By this the rheological behavior of the material changes dramatically. All these circumstances make rubber processing to a very complex theme. This paper presents results which are obtained within an European research project. The work is focussing on a better process description of the extrusion process of rubber compounds. It handles both applications of the extrusion process, i. e. for technical rubber goods or for making tire parts like the extrusion of tread stripes. Hence in this paper a new approach for modeling the flow in the extruder screw will be presented. Using this as a simulation tool a systematic analysis of the extrusion process is possible in reasonable time. Another field of interest in this context is the rheological characterization of rubber compounds with a so called „Extrusion-Rheometer“. The advantages of this device will be shown for the investigation of processability and gathering representative rheological data for recalculations of screw and die flow in the extrusion process.

scholarly journals Rheological characterization of the die swell phenomenon of rubber compounds

2007 ◽  
Vol 26 (8) ◽  
pp. 1041-1048 ◽  
Author(s):  
Herbert W. Müllner ◽  
Josef Eberhardsteiner ◽  
Wolfgang Fidi
Keyword(s):  
Die Swell ◽  
Rheological Characterization ◽  
Rubber Compounds

scholarly journals Rheological Characterization of Isabgol Husk, Gum Katira Hydrocolloids, and Their Blends

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Vipin Kumar Sharma ◽  
Bhaskar Mazumder ◽  
Vinod Nautiyal
Keyword(s):  
Phosphate Buffer ◽  
Power Flow ◽  
Thermal Conditions ◽  
Gel Strength ◽  
Rheological Parameters ◽  
Flow Index ◽  
Distilled Water ◽  
Rheological Characterization ◽  
Dispersion Media

The rheological parameters of Isabgol husk, gum katira, and their blends were determined in different media such as distilled water, 0.1 N HCl, and phosphate buffer (pH 7.4). The blend properties of Isabgol husk and gum katira were measured for four different percentage compositions in order to understand their compatibility in dispersion form such as 00 : 100, 25 : 50, 50 : 50, 75 : 25, and 100 : 00 in the gel strength of 1 mass%. The miscibility of blends was determined by calculating Isabgol husk-gum katira interaction parameters by Krigbaum and Wall equation. Other rheological properties were analyzed by Bingham, Power, Casson, Casson chocolate, and IPC paste analysis. The study revealed that the power flow index “p” was less than “1” in all concentrations of Isabgol husk, gum katira, and their blends dispersions indicating the shear-thinning (pseudoplastic) behavior. All blends followed pseudoplastic behavior at thermal conditions as 298.15, 313.15, and 333.15°K and in dispersion media such as distilled water, 0.1 N HCl, and phosphate buffer (pH 7.4). Moreover, the study indicated the applicability of these blends in the development of drug delivery systems and in industries, for example, ice-cream, paste, nutraceutical, and so forth.

scholarly journals Rheological Characterization of Non-Newtonian Mixtures by Pressure Pipe Tests

Fluids ◽  
2021 ◽  
Vol 6 (11) ◽  
pp. 419
Author(s):  
Armando Carravetta ◽  
Oreste Fecarotta ◽  
Riccardo Martino ◽  
Maria Cristina Morani
Keyword(s):  
Experimental Tests ◽  
Rheological Parameters ◽  
Rheological Characterization ◽  
Plastic Model ◽  
The Past ◽  
Pressure Pipe ◽  
Complete Set ◽  
Constitutive Parameters ◽  
Better Than

The rheological behavior of non-Newtonian fluids in turbulent conditions is an important topic in several fields of engineering. Nevertheless, this topic was not deeply investigated in the past due to the complexity of the experimental tests for the assessment of the constitutive parameters. Pressure pipe tests on Herschel-Bulkley mixtures were proven to be suitable for exploring turbulent conditions, but discrepancies with the results of tests performed in laminar flow were detected. These contradictions could be attributed to the inconsistencies of the Herschel-Bulkley model (HB) for high shear rate flows, proven by Hallbom and Klein, who suggested a more general “yield plastic” model (HK). Hence, in this study, a procedure for the estimation of the rheological parameters of both HB and HK models in pressure pipe tests is defined and rated on a complete set of experiments. The HK model performed much better than HB model in the turbulent range and slightly better than the HB model in the laminar range, confirming the consistency of the “yield plastic” model. The rheological parameters obtained by the proposed procedure were used to numerically model a dam-break propagation of a non-Newtonian fluid, showing significant differences in terms of process evolution depending on the constitutive model.

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