scholarly journals Rheological Behavior of the Composites of Carboxymethylcellulose-Zinc Oxide/Starch

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Marcio Da Silva Coutinho ◽  
Danielle Cristina Fernandes Da Silva ◽  
Gustavo Ribeiro Xavier ◽  
Norma Gouvêa Rumjanek ◽  
Paulo Jansen De Oliveira
Keyword(s):  
Zinc Oxide ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Arrhenius Equation ◽  
Flow Behavior ◽  
High Shear ◽  
Recovery Test ◽  
Creep And Recovery ◽  
Rate Testing ◽  
Starch Blends

The rheological behavior of the carboxymethylcellulose (CMC) / starch blends with and without zinc oxide (ZnO) have been investigated by controlled shear rate testing ramps. All blends showed high shear thinning flow behavior, (n=0,10 - 0,32) without ZnO and (n=0,10-0,29) with ZnO. The consistency index (K) and apparent viscosity (ηa,100 ) decreased with increasing amount of starch and with the addition of 1% wt ZnO. The results also showed that occurs an inversion in the elastic and viscous modulii behavior between 25 and 700C, obeying the Arrhenius equation. The study of activation energy showed that ZnO acts in the CMC phase, increase of viscosity of mixtures. The creep and recovery test indicated a decrease in the viscosity zero shear rate, indicating an increase of viscous character.  The phase angle results also confirm an increase of viscosity with addition of ZnO.

Rheology of Liquid Al, Zn and Zn-7wt%Al Systems

2011 ◽  
Vol 690 ◽  
pp. 226-229 ◽  
Author(s):  
Manickaraj Jeyakumar ◽  
Sumanth Shankar
Keyword(s):  
Shear Rate ◽  
Liquid Metal ◽  
Temperature Dependence ◽  
Arrhenius Equation ◽  
Flow Behavior ◽  
Pure Aluminum ◽  
High Shear Rate ◽  
High Shear ◽  
Shear Rates ◽  
Effects Of Temperature

The flow behavior and viscosity of pure aluminum, zinc and Zn-7wt%Al liquids were quantified with the effects of temperature and shear rate by rotational rheometry experiments. These systems exhibited a non-Newtonian, shear thinning and non-thixotropic flow behavior where in the liquid metal viscosity decreases with increasing shear rates. The temperature dependence of viscosity followed the Arrhenius equation. Moreover, at high shear rate regimes the flow resembles a nearly Newtonian behaviour.

Rheological behavior of SAN/PC blends under extremely high shear rate

1989 ◽  
Vol 37 (7) ◽  
pp. 1837-1853 ◽  
Author(s):  
Hideroh Takahashi ◽  
Takaaki Matsuoka ◽  
Takashi Ohta ◽  
Kenzo Fukumori ◽  
Toshio Kurauchi ◽  
...  
Keyword(s):  
Shear Rate ◽  
Rheological Behavior ◽  
High Shear Rate ◽  
High Shear

The Rheological Properties of Turkish Delight

2009 ◽  
Vol 6 (1) ◽  
Author(s):  
Zurriye Yilmaz ◽  
Mehmet Dogan ◽  
Mahir Alkan ◽  
Serap Dogan
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Power Law ◽  
Food Industry ◽  
Arrhenius Equation ◽  
Flow Behavior ◽  
Effect Of Temperature ◽  
Flow Properties ◽  
Different Temperatures ◽  
Dependent Flow

In the food industry, rheological properties, such as viscosity, shear rate, and shear stress, are the most important parameters required in the design of a technological process. Therefore, in this study, we determined the flow behavior and the time-dependent flow properties of Turkish Delight (TD) in the temperature range of 25-75°C using a capillar rheometer. The structure and thermal properties of TD were investigated by XRD and a simultaneous DTA/TG analysis. The shear rate values ranged from 5 to 300s-1. We found that: (i) TD behaved as non- Newtonian pseudoplastic foodstuff; (ii) while the measurement temperature increased, viscosity decreased; and (iii) TD was a rheopectic material. The effect of temperature on viscosity was described by means of the Arrhenius equation. The activation energies for the flow of pseudoplastic TD varied from 50.1-74.2 kJ/mol, depending on shear rate. Three models were used to predict the flow behavior of TD, namely, the Power law, Bingham and Casson models. The Power law model adequately described well the flow behavior of TD at different temperatures.

Nonnewtonian Flow of Poly(Dimethyl Siloxane)

1967 ◽  
Vol 40 (5) ◽  
pp. 1483-1491
Author(s):  
Yoshio Ito
Keyword(s):  
Shear Rate ◽  
Polymer Solutions ◽  
Flow Behavior ◽  
Degree Of Polymerization ◽  
High Shear ◽  
Newtonian Viscosity ◽  
Shear Rates ◽  
Molecular Weights ◽  
Dimethyl Siloxane ◽  
Wide Range

Abstract Nonnewtonian flow of poly(dimethyl siloxanes) of various molecular weights has been studied with a short capillary viscosimeter. The experiment covered a wide range of shear rate, from 10−1 to 3×106sec−1. Results were as follows: (1) Flow behavior of the sample changes with the degree of polymerization. For siloxanes with degrees of polymerization less than 1.55×102, flow of the fluid is newtonian throughout the whole range of shear rates; for siloxanes with degrees of polymerization from 3.22×102 to 2.63×103, flow is nonnewtonian at moderate shear rates; it again becomes newtonian at high shear rates. With degrees of polymerization more than 3.31×103, the spiral flow rises to a high shear rate. (2) Plow behavior of the samples is expressed by modifying Shishido's equation proposed for nonnewtonian polymer solutions. (3) When the observed flow curve contains its inflection point, the upper newtonian viscosity can be estimated by a new method proposed here. (4) The relations among the end correction of capillary, the pressure loss, and the shear stress proposed by Shishido for polymer solutions are applicable to poly(dimethy! siloxane) also.

scholarly journals Aqueous Solutions of Polyethoxylated Fatty Alcohols Rheological behavior and superficial properties

2019 ◽  
Vol 70 (2) ◽  
pp. 382-386
Author(s):  
Andra Tamas ◽  
Sabina Nitu
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Aqueous Solutions ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Fatty Alcohols ◽  
Flow Behavior Index ◽  
Foaming Power ◽  
Newtonian Behavior ◽  
Behavior Index

The paper presents the study of the rheological and superficial behavior (foaming power and wetting capacity) of some aqueous solutions with polyethoxylated fatty alcohols content. The influence of fatty alcohols concentration and their degree of ethoxylation as well as that of temperature on the rheological behavior was determined from the dependences between the shear stress t and the shear rate. The results demonstrate that all the studied solutions have non-Newtonian behavior, with flow behavior index smaller than 1.

Effect of temperature on the rheological behavior of sugary cassava

2020 ◽  
pp. 125
Author(s):  
Leiliane do Socorro Sodré Souza ◽  
Tatiane Pereira de Souza ◽  
Rafael Lopes e Oliveira ◽  
Sérgio Duvoisin Junior ◽  
Ari de Freitas Hidalgo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Food Production ◽  
Arrhenius Equation ◽  
Effect Of Temperature ◽  
Rheological Models ◽  
Rate Range ◽  
Fermented Beverages ◽  
Three Samples

The rheological behavior of the juice extracted from sugary cassava roots, a type of cassava that stored the largest amount of sugars and the starch as it was, at various temperatures (9-65ºC) and in concentrations of 5ºBrix, 10.5ºBrix, and 18.5ºBrix. The experiments were performed on a Brookfield viscometer in a shear rate range of 0.01-237.6 s-1. The rheological models of Newton, Bingham, and Ostwald-De-Waele were fitted to the experimental results. The Newton model describes well the rheological behavior of the three samples evaluated. The effect of temperature on viscosity was evaluated using an Arrhenius equation; the viscosity value is influenced by the same temperature. The activation energy values ​​for the concentrations of 5ºBrix, 10.5ºBrix and 18.5ºBrix correspond to 3.14 kcal mol-1, 3.53 kcal mol-1 and 3.71 kcal mol-1. This type of cassava can be used in the production of ethanol, fermented beverages and syrups. It is also an important alternative for food production, as the cultivation of cassava can be classified as less aggressive to the environment, in comparison with sugarcane.

scholarly journals Rheological Properties of Polysaccharides from Longan (Dimocarpus longanLour.) Fruit

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Xingxun Liu ◽  
Yongyue Luo ◽  
Chunjie Zha ◽  
Sumei Zhou ◽  
Liya Liu ◽  
...  
Keyword(s):  
Shear Rate ◽  
Chemical Analysis ◽  
Rheological Properties ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Small Amplitude ◽  
Flow Behavior ◽  
Viscoelastic Behavior ◽  
Dynamic Shear ◽  
Small Amplitude Oscillatory Shear

Longan polysaccharide (LP) was extracted from longan (Dimocarpus longanLour.) pulp. The composition and rheological properties were determined by chemical analysis and dynamic shear rheometer. The flow behavior and viscoelastic behavior of longan polysaccharide (LP) solution were investigated by steady shear and small amplitude oscillatory shear (SAOS) experiments, respectively. The result shows that the solution is a pseudoplastic flow in a range of shear rate (1–100 s−1). The rheological behavior of LP was influenced by cations such as Na+and Ca2+. With an increase of apparent viscosity,G′andG′′were accompanied by addition of Na+and Ca2+.

An Influence of a Binder System to the Rheological Behavior of the SS316L Metal Injection Molding (MIM) Feedstock

2011 ◽  
Vol 264-265 ◽  
pp. 554-558 ◽  
Author(s):  
Khairur Rijal Jamaludin ◽  
Norhamidi Muhamad ◽  
Hooman Abolhasani ◽  
Hadi Murthadha ◽  
Mohd Nizam Ab. Rahman
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Injection Molding ◽  
Rheological Behavior ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Binder System ◽  
Flow Behavior Index ◽  
Injection Molded

The influence of a binder system to the rheological behavior of a Metal Injection Molding (MIM) feedstock is presented in the paper. The binder systems used are: a) PEG & PMMA b) Palm stearin & LLDPE and, c) Tapioca starch & LLDPE. The viscosity and shear rate of the feedstocks were measured at various range of temperature and shear rate across the L/D = 10 capillary rheometer. The flow behavior index, n and activation energy, E of each feedstock were measured to show its significance as MIM feedstock. Generally, the result indicates all feedstock exhibits a shear thinning behavior and the binders are suitable as MIM binder. Additionally, the present paper has discovered that the binder system does not have much influence to the activation energy. In order to show the relevance of the rheological behavior to the actual injection molding performance, green parts has been injection molded and the result shows an agreement with the rheological behavior result.

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