Influence of Chemical Nature on Flow Behavior of Polymers. I. Shear Rate and Temperature Dependence

1970 ◽  
Vol 43 (5) ◽  
pp. 1109-1115 ◽  
Author(s):  
E. A. Collins ◽  
T. Mass ◽  
W. H. Bauer
Keyword(s):  
Molecular Weight ◽  
Shear Rate ◽  
Chemical Nature ◽  
Flow Behavior ◽  
Capillary Viscometer ◽  
Low Molecular Weight ◽  
Flow Activation Energy ◽  
Flow Activation ◽  
Made In ◽  
Low Shear

Abstract The flow behavior of low molecular weight liquid polybutadiene polymers was studied as a function of shear rate, temperature, and molecular structure. Measurements were made in the temperature range 15 to 50° C and shear rate range 1 to 15,000 sec−1 with a cone and plate and a capillary viscometer. Limiting low shear viscosity, flow activation energy, and critical shear rate marking onset of shear rate thinning were found to be strongly dependent upon the presence of functional groups such as hydroxyl, carboxyl, and nitrile. The modifying groups showed a greater effect than the molecular weight upon the properties measured.

Research on the Rheological Properties of Domestic and International PPS Resin

2012 ◽  
Vol 535-537 ◽  
pp. 2517-2521
Author(s):  
Rui Ping Zhang ◽  
Peng Wei Xiang ◽  
Jin Ming Dai ◽  
Jian Ying Zhang ◽  
Mei Niu ◽  
...  
Keyword(s):  
Shear Rate ◽  
Viscous Flow ◽  
Apparent Viscosity ◽  
Viscosity Index ◽  
Capillary Rheometer ◽  
Flow Activation Energy ◽  
Japanese Sample ◽  
Flow Activation ◽  
Spinning Speed ◽  
Low Shear

Using the capillary rheometer to study the effect of shear rate, shear stress and temperature of Japanese and domestic PPS resin( fiber grade) on the apparent viscosity, index of non-Newtonian and viscous flow activation energy.The results show that with the increase of shear rate and temperature,compared to the domestic sample, Japanese sample has higher apparent viscosity, smaller non-Newtonian index(n),lower viscous flow activation energy,and smaller sensitivity to temperature.The Japanese specimens are suitable for processing and forming under high shear rate and spinning speed, but the domestic specimens are suitable for processing and froming under low shear rate and spinning speed.

Flow Behavior of Heterocyclic Aramid Concentrated Solution

2010 ◽  
Vol 146-147 ◽  
pp. 470-474
Author(s):  
Lei Chen ◽  
Zu Ming Hu ◽  
Bao Shan Gao ◽  
Guo Ping Tang ◽  
Jun Rong Yu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Molecular Weight ◽  
Flow Behavior ◽  
Viscosity Index ◽  
Solution Concentration ◽  
Structural Viscosity ◽  
Flow Activation Energy ◽  
Flow Activation ◽  
Concentrated Solution ◽  
Newtonian Behavior

By means of HAAKE RS105L cone and plate rheometer the rheological behavior of heterocyclic aramid concentrated solution, including viscous flow activation energy, non-Newtonian index, structural viscosity index of the heterocyclic aramid solution were studied. The effect of concentration and temperature of the solution and molecular weight of the polymer on its non-Newtonian behavior was investigated. The results showed that heterocyclic aramid concentrated solution prepared via low temperature condensation was non-Newtonian fluid. With the decrease of temperature, increase of solution concentration and heterocyclic aramid molecular weight, the deviation of the solution from Newtonian behavior decreased. The molecular weight of the polymer and the concentration of the solution affected the non-Newtonian behavior more intensively.

scholarly journals Certain Rheological Aspects of Functionalized Guar Gum

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Meenu Kapoor ◽  
Dhriti Khandal ◽  
Ruchi Gupta ◽  
Pinklesh Arora ◽  
Geetha Seshadri ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shear Rate ◽  
Guar Gum ◽  
Loss Modulus ◽  
Industrial Applications ◽  
Green Technology ◽  
Low Molecular Weight ◽  
Radiation Processing ◽  
Industrial Sectors ◽  
Wide Acceptance

Guar gum and its derivatives are highly important industrial hydrocolloids as they find applications in various industrial sectors. Guar is a polymer of high molecular weight and its aqueous solutions exhibit unique rheological properties, which has led to its wide acceptance by the industry. In certain industrial applications low molecular weight guar and its derivatives are needed, and conventionally chemical depolymerisation of guar is carried out for this purpose. Radiation processing is a novel and green technology for carrying out depolymerization and can be an ideal substitute for chemical depolymerisation technique. In order to study the effect of radiation on guar derivatives, three types of derivatives have been taken in the present study: carboxymethyl, hydroxyethyl, and methyl guar. The effect of 1–50 KGy radiation dose on the rheological behavior of these derivatives has been studied, and the results have been described in the present paper. The effect on storage and loss modulus with respect to frequency and effect on viscosity with respect to shear rate have been discussed in detail.

Rheological Study on of PBT with High Melt Flow Index

2012 ◽  
Vol 487 ◽  
pp. 644-648
Author(s):  
Yuan Liu ◽  
Lin Wang ◽  
Qing Yan Xu ◽  
Pei Jie Lin ◽  
Zhi Hong Guo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Apparent Viscosity ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Flow Activation Energy ◽  
Nonwoven Fabrics ◽  
Flow Activation ◽  
High Flexibility

Melt-blown generated PBT nonwoven fabrics usually have small fibril diameter, high flexibility, well heat and oil resistance. Therefore, they would have promising application such as vehicle filtering media. The rheological behavior of PBT with High Melt Flow Index for Melt-blown is investigated in this paper. It is a direction of the technology design and fabrication parameters .The relation of apparent viscosity and shear rate is analyzed, as well as flow activation energy and Non-Newtonian indexes. The results suggest that PBT with High Melt Flow Index is Non-Newtonian fluid. Apparent viscosity and flow activation energy show gradually decrease with increasing shear rate, exhibiting typical shear-thinning behavior.

GRAFT COPOLYMERS OF STYRENE AND METHYL METHACRYLATE: PART II: VISCOSITY BEHAVIOR

1956 ◽  
Vol 34 (8) ◽  
pp. 1027-1036 ◽  
Author(s):  
M. H. Jones
Keyword(s):  
Shear Rate ◽  
Methyl Methacrylate ◽  
Graft Copolymers ◽  
Free Fall ◽  
Capillary Viscometer ◽  
Linear Polymers ◽  
Viscosity Behavior ◽  
Shear Gradient ◽  
Constant Shear Rate ◽  
Made In

A study of the viscosity behavior of the graft copolymers described in Part I has been made with dilute solutions in benzene at 25 °C. Although the slope constants of the Huggins equation increase with the frequency of branching when measurements are made in a capillary viscometer under 'free fall' conditions, this is shown to be attributable to the dependence of viscosity on shear gradient. At a constant shear rate, the Huggins k′ values approximate to those of linear polymers. It is suggested that the marked increase in viscosity observed with decreasing shear rate for the graft copolymers is due to molecular entanglement.

scholarly journals Rheological Behavior and Its Chemical Interpretation of Crumb Rubber Modified Asphalt Containing Warm-Mix Additives

2018 ◽  
Vol 2672 (28) ◽  
pp. 337-348 ◽  
Author(s):  
Haopeng Wang ◽  
Xueyan Liu ◽  
Panos Apostolidis ◽  
Tom Scarpas
Keyword(s):  
Activation Energy ◽  
Molecular Weight ◽  
Rheological Properties ◽  
Phase Angle ◽  
Complex Modulus ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Flow Activation Energy ◽  
Modified Asphalt ◽  
Flow Activation

The microstructure and chemical composition of asphalt binders have a significant effect on their rheological properties and, therefore, their performance as road paving binders. This study aims to investigate the effects of warm-mix asphalt (WMA) additives, organic type and chemical type, on the rheological properties and chemical internal structure of base asphalt and crumb rubber modified asphalt (CRMA). A set of dynamic shear rheometer (DSR) tests was conducted to obtain the rheological parameters (e.g., complex viscosity, complex modulus, phase angle) of asphalt binders. The flow activation energy was calculated from Arrhenius equation based on viscosity data to rank the thermal susceptibility. Black diagrams and master curves of complex modulus and phase angle were utilized to analyze the rheological properties. The molecular weight distributions of asphalt binders were inverted from the phase angle master curve to evaluate the molecular weight characteristics. It was found that the the addition of crumb rubber into base asphalt improves the rheological properties of enhanced modulus and elasticity. Organic and chemical types of WMA additives have different chemo-physical effects on both base asphalt and CRMA. Phase angle inversion method provides a powerful tool to monitor the molecular structure change and, therefore, the chemo-physical interactions of asphalt binders induced by modifications. Finally, there is a good correlation between flow activation energy and molecular weight.

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