Rheological behavior of binary polymer compositions

The article presents the results of a study of the rheological behavior of binary composites based on serial polyethylene grade LDPE 15803-020 with different content of microcellulose grade Filtracell, in a wide range of temperatures and shear rates during deformation through a capillary diameter of 1 mm and a length of 5 and 30 mm. Stable flow regime is manifested in the temperature range from 160 to 200°C for composites containing microcellulose in an amount of 30 wt.%, and its partial replacement with spent microcellulose (waste production of vegetable oils) can reduce the effective viscosity to 25%, but the upper limit of the temperature range is limited to the exudation of impurities (190°C). The Bagley correction is carried out, the coefficients of the equations describing the dependences of the true shear stress, regardless of the capillary length, are calculated.

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Empirical Estimation of Ethanol-Methylcellulose based Green Gel Propellant Viscosity at Varying Temperature

Journal of University of Shanghai for Science and Technology ◽

10.51201/jusst/21/07323 ◽

2021 ◽

Vol 23 (07) ◽

pp. 1293-1302

Author(s):

Saugata Mandal ◽

◽

Balaguru Pandian ◽

Rajarshi Das ◽

◽

...

Keyword(s):

Experimental Data ◽

Power Law ◽

Empirical Model ◽

Rheological Behavior ◽

Empirical Estimation ◽

Propulsion Systems ◽

Shear Rates ◽

Temperature Range ◽

Shear Thinning Fluids ◽

Good Agreement

The rheological behavior of the Ethanol based green gels for use in propulsion systems at temperature range of 100C – 500C is investigated by employing a novel empirical model developed. The study is conducted at various shear rates. Empirically predicted results were observed to be in good agreement with experimental data at higher shear rates for both pure and energized gel system (>100 s-1). Considering the results, the present empirical model is deemed suitable for those Non Newtonian shear thinning fluids which obey Power law.

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Rheological study of orange honey with influence on concentration

Oriental Journal Of Chemistry ◽

10.13005/ojc/370413 ◽

2021 ◽

Vol 37 (4) ◽

pp. 864-867

Author(s):

Ioana Stanciu

Keyword(s):

Rheological Behavior ◽

High Shear ◽

Rheological Study ◽

Shear Rates ◽

Temperature Range ◽

High Shear Rates ◽

Viscosity Sensor

The rheological behavior of orange honey was studied in the temperature range 25-45 degrees Celsius with Haake VT 550 viscometer when the HV1 viscosity sensor at high shear rates 3.3 and 1312s-1. The assortment of orange honey has a dilating behavior being influenced by concentration and humidity. Honey was studied with a humidity of 16%, 17%, 19% and 21%. The rheological behavior is influenced by both humidity and its composition.

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Experimental Study of Micronized Coal/Water Slurry Rheology at High Shear Rates

Journal of Energy Resources Technology ◽

10.1115/1.2905710 ◽

1990 ◽

Vol 112 (1) ◽

pp. 36-40 ◽

Cited By ~ 6

Author(s):

Y. I. Cho ◽

U. S. Choi

Keyword(s):

Diesel Engines ◽

Rheological Behavior ◽

Capillary Tube ◽

Operating Conditions ◽

Rheological Characterization ◽

Shear Rates ◽

Water Slurry ◽

Wide Range ◽

Coal Water Slurry ◽

Slurry Rheology

The rheological behavior of four micronized coal water slurry (CWS) samples was studied experimentally for a wide range of shear rates between 3 and 30,000 s−1. The systematic rheological characterization of the slurry fuel shows that the rheological behavior of these CWS is very complex and depends on coal particle size, temperature, coal loading, conditioning additives, and the capillary tube diameter as well as the shear rate. This study indicates that better appreciation of the unique and complex rheological behavior of non-Newtonian CWS fuels is vital to developing high-quality slurries suitable for use in coal-fired diesel engines, and suggests that a more comprehensive data base for CWS rheology under actual diesel engine operating conditions is needed prior to using such CWS fuels in diesel engines.

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Enabling highly reversible sodium metal cycling across a wide temperature range with dual-salt electrolytes

Journal of Materials Chemistry A ◽

10.1039/d1ta00842k ◽

2021 ◽

Author(s):

Akila C. Thenuwara ◽

Pralav P. Shetty ◽

Neha Kondekar ◽

Chuanlong Wang ◽

Weiyang Li ◽

...

Keyword(s):

Wide Temperature Range ◽

High Energy ◽

Liquid Electrolyte ◽

Metal Cycling ◽

Temperature Range ◽

Sodium Metal ◽

Wide Range

A new dual-salt liquid electrolyte is developed that enables the reversible operation of high-energy sodium-metal-based batteries over a wide range of temperatures down to −50 °C.

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Impact of Powder Properties on the Rheological Behavior of Excipients

Pharmaceutics ◽

10.3390/pharmaceutics13081198 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1198

Author(s):

Pauline H. M. Janssen ◽

Sébastien Depaifve ◽

Aurélien Neveu ◽

Filip Francqui ◽

Bastiaan H. J. Dickhoff

Keyword(s):

Flow Field ◽

Rheological Behavior ◽

Quality By Design ◽

Filling Process ◽

Dynamic Flow ◽

Die Filling ◽

Flow Characterization ◽

Wide Range ◽

Powder Properties ◽

The Impact

With the emergence of quality by design in the pharmaceutical industry, it becomes imperative to gain a deeper mechanistic understanding of factors impacting the flow of a formulation into tableting dies. Many flow characterization techniques are present, but so far only a few have shown to mimic the die filling process successfully. One of the challenges in mimicking the die filling process is the impact of rheological powder behavior as a result of differences in flow field in the feeding frame. In the current study, the rheological behavior was investigated for a wide range of excipients with a wide range of material properties. A new parameter for rheological behavior was introduced, which is a measure for the change in dynamic cohesive index upon changes in flow field. Particle size distribution was identified as a main contributing factor to the rheological behavior of powders. The presence of fines between larger particles turned out to reduce the rheological index, which the authors explain by improved particle separation at more dynamic flow fields. This study also revealed that obtained insights on rheological behavior can be used to optimize agitator settings in a tableting machine.

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Recent Attempts in the Design of Efficient PVC Plasticizers with Reduced Migration

Materials ◽

10.3390/ma14040844 ◽

2021 ◽

Vol 14 (4) ◽

pp. 844

Author(s):

Joanna Czogała ◽

Ewa Pankalla ◽

Roman Turczyn

Keyword(s):

Mechanical Properties ◽

Partial Replacement ◽

Total Replacement ◽

Current Trends ◽

Poly Vinyl Chloride ◽

Wide Range ◽

Migration Resistance ◽

Secondary Plasticizer ◽

New Compounds ◽

Ethylhexyl Phthalate

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.

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VISCOSITY OF NATURAL RUBBER SOLUTIONS AT VERY LOW RATES OF SHEAR

Canadian Journal of Chemistry ◽

10.1139/v57-056 ◽

1957 ◽

Vol 35 (4) ◽

pp. 381-387 ◽

Cited By ~ 3

Author(s):

Morton A. Golub

Keyword(s):

Experimental Data ◽

Natural Rubber ◽

Pressure Head ◽

Viscosity Data ◽

Theoretical Relation ◽

Newtonian Flow ◽

Shear Rates ◽

Reduced Viscosity ◽

Wide Range ◽

Composite Data

The shear dependence of viscosity of benzene solutions of natural rubber was studied at rates of shear from about 500 down to less than 1 sec.−1. Measurements involved following the change of pressure head with time of the various solutions flowing in a capillary, U-tube viscometer. Curvature in the plots of the logarithm of pressure head versus time indicated non-Newtonian flow. From such curves, reduced viscosity data over the above-mentioned shear range were readily derived. As a check, data over the range 100–500 sec.−1 were also obtained with a five-bulb viscometer of the Krigbaum–Flory type, and these data overlapped those obtained with the U tube. The reduced viscosity increased very sharply with decrease in gradient, making extrapolation to the viscosity axis quite unreliable. However, a theoretical relation proposed by Bueche fitted the composite data rather well. This work furnished a nice technique for determining the zero shear reduced viscosity (ηap/c)0 without the necessity of performing an uncertain extrapolation: evaluate the parameters of the Bueche formula which best satisfies the experimental data over a fairly wide range of shear rates, and then calculate (ηap/c)0 directly.

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The Effects of Acclimation Temperature on a Neuromuscular System of the Crayfish, Astacus Leptodactylus

Journal of Experimental Biology ◽

10.1242/jeb.78.1.281 ◽

1979 ◽

Vol 78 (1) ◽

pp. 281-293

Author(s):

MIKKO HARRI ◽

ERNST FLOREY

Keyword(s):

Membrane Lipids ◽

Characteristic Temperature ◽

Resting Membrane Potential ◽

Acclimation Temperature ◽

Muscle Fibres ◽

Astacus Leptodactylus ◽

Tension Development ◽

Temperature Range ◽

Wide Range ◽

Warm Acclimation

1. Crayfish, Astacus leptodactylus, were acclimated to 12 °C and to 25 °C. Nerve muscle preparations (closer muscle of walking legs) were subjected to temperatures ranging from 6 to 32 °C. 2. The resting membrane potential of muscle fibres was found to increase with temperature in a linear manner, but with a change in slope at around 170 in cold-acclimated preparations, and around 24 °C in warm-acclimated ones. 3. Temperature acclimation shifted the temperature range of maximal amplitudes of fast and slow e.j.p.s toward the acclimation temperature. Optimal facilitation of slow e.j.p.s also occurred near the respective acclimation temperature. 4. E.j.p. decay time is nearly independent of temperature in the upper temperature range but increases steeply when the temperature falls below a critical range around 17 °C in preparations from cold-acclimated animals, and around 22 °C after acclimation to 25 °C. 5. Peak depolarizations reached by summating facilitated e.j.p.s are conspicuously independent of temperature over a wide range (slow and fast e.j.p.s of cold-acclimated preparations, fast e.j.p.s of warm-acclimated ones) which extends to higher temperatures after warm acclimation in the case of fast e.j.p.s. In warm-acclimated preparations the peak depolarization of slow e.j.p.s first falls then rises and falls again as the temperature increases from 8 to 32 °C. 6. Tension development elicited by stimulation of the slow axon at a given frequency reaches maximal values at the lower end of the temperature range in cold-acclimated preparations. The maximum is shifted towards 20 °C after warm acclimation. Fast contractions decline with temperature; possible acclimation effects are masked by the great lability of fast contractions in warm-acclimated preparations. 7. It is suggested that changes in the composition of membrane lipids may be responsible for the effects of acclimation on the electrical parameters and their characteristic temperature dependence.

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Preparation and Thermoelectric Properties of Graphite/poly(3,4-ethyenedioxythiophene) Nanocomposites

Energies ◽

10.3390/en11102849 ◽

2018 ◽

Vol 11 (10) ◽

pp. 2849 ◽

Cited By ~ 5

Author(s):

Yong Du ◽

Haixia Li ◽

Xuechen Jia ◽

Yunchen Dou ◽

Jiayue Xu ◽

...

Keyword(s):

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Power Factor ◽

Oxidative Polymerization ◽

Polymerization Process ◽

Measurement Temperature ◽

Temperature Range ◽

Different Content

Graphite/poly(3,4-ethyenedioxythiophene) (PEDOT) nanocomposites were prepared by an in-situ oxidative polymerization process. The electrical conductivity and Seebeck coefficient of the graphite/PEDOT nanocomposites with different content of graphite were measured in the temperature range from 300 K to 380 K. The results show that as the content of graphite increased from 0 to 37.2 wt %, the electrical conductivity of the nanocomposites increased sharply from 3.6 S/cm to 80.1 S/cm, while the Seebeck coefficient kept almost the same value (in the range between 12.0 μV/K to 15.1 μV/K) at 300 K, which lead to an increased power factor. The Seebeck coefficient of the nanocomposites increased from 300 K to 380 K, while the electrical conductivity did not substantially depend on the measurement temperature. As a result, a power factor of 3.2 μWm−1 K−2 at 380 K was obtained for the nanocomposites with 37.2 wt % graphite.

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