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.

Rheological Behaviors of Graphene Oxide/Polyacrylonitrile Spinning Solutions

2017 ◽  
Vol 898 ◽  
pp. 2187-2196 ◽  
Author(s):  
Feng Mei Li ◽  
Ying Ying Zheng ◽  
Biao Wang
Keyword(s):  
Activation Energy ◽  
Graphene Oxide ◽  
Loss Factor ◽  
Viscosity Index ◽  
Structural Viscosity ◽  
Mechanical Loss ◽  
Flow Activation Energy ◽  
Rheological Behaviors ◽  
Flow Activation ◽  
Mechanical Loss Factor

The rheological behaviors of polyacrylonitrile (PAN) in NaSCN aqueous solutions containing different amount of Graphene oxide (GO) were investigated through both steady-state and dynamic rheological measurements. The parameters such as apparent viscosity (ηα), flow activation energy (Eη), structural viscosity index (Δη), storage modulus (G’), loss modulus (G’’) and mechanical loss factor (tanδ) were measured to illustrate the rheological behaviors of these solutions. The results showed that the apparent viscosity decreased with adding appropriate amount of GO, while the structural viscosity index, the flow activation energy and the mechanical loss factor of GO/PAN spinning solutions increased. Accordingly, a possible mechanism of GO effect on rheological behaviors of PAN solution was proposed in this work.

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.

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.

Some Aspects of the Relationship between Molecular Structure and Flow Behavior of Polymer Melts

1969 ◽  
Vol 42 (3) ◽  
pp. 823-834 ◽  
Author(s):  
L. L. Blyler
Keyword(s):  
Molecular Structure ◽  
Activation Energy ◽  
Molecular Weight ◽  
Molecular Mechanisms ◽  
Flow Behavior ◽  
Average Molecular Weight ◽  
Melt Fracture ◽  
Flow Activation Energy ◽  
Shear Dependent Viscosity ◽  
Dependent Viscosity

Abstract The shear dependent viscosity and related properties of a number of ethylene polymers of differing molecular structure have been characterized using a capillary extrusion rheometer. The structural aspects of interest were average molecular weight, branching, and the presence of strong intermolecular secondary forces. It was found that average molecular weight influences the degree of shear dependence of the viscosity, branching affects both flow activation energy and the nature of the observed “melt fracture” phenomenon, and intermolecular hydrogen bonding enhances viscosity and activation energy and leads to increased shear dependence of flow behavior. The results are interpreted in terms of specific molecular mechanisms.

Rheological Analysis of Microminiature Powder Injection Molding (μPIM) Feedstock

2011 ◽  
Vol 52-54 ◽  
pp. 238-243 ◽  
Author(s):  
Haw Pei Li ◽  
Norhamidi Muhamad
Keyword(s):  
Activation Energy ◽  
Injection Molding ◽  
Power Law ◽  
Flow Behavior ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Flow Activation Energy ◽  
Rheological Analysis ◽  
Power Law Exponent ◽  
Flow Activation

A rheological analysis has been performed to evaluate the characteristics and behaviors of Microminiature Powder Injection Molding (μPIM) feedstocks. The feedstocks comprised of 316L stainless steel powder and water-based binder components. Feedstocks formulations with powder loading of 59% to 63% were prepared and investigated. In these formulations, the binder system consists of 65% Polyethelena Glycol (PEG), 25% Polymethyl Methacrilate (PMMA) and 10% Cellulose Acetate Butyrate (CAB) based on the weight fraction. The influences of rheological behaviors such as flow activation energy (E), Power-Law exponent (n), viscosity (η) and temperature (T) of the SS316L/PEG/PMMA/CAB feedstocks are analyzed and discussed. Results show that all of the feedstocks exhibited the pseudo-plastic flow behavior. The homogenous feedstock at 61 vol. % demonstrated the most satisfactory rheological properties for μPIM with the lowest flow activation energy, Power-Law exponent, n < 1 and moderate viscosity values. It was chosen to perform the injection molding process. Micro components have been replicated successfully by using this selected feedstock.

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.

Rheological Properties of Blend Spinning Solution of Sodium Alginate and TiO2 Nanoparticles

2012 ◽  
Vol 430-432 ◽  
pp. 301-305
Author(s):  
Li Wen Tan ◽  
Dong Mei Xu ◽  
Quan Ji ◽  
Bing Bing Wang ◽  
Yan Zhi Xia
Keyword(s):  
Rheological Properties ◽  
Sodium Alginate ◽  
Apparent Viscosity ◽  
Flow Behavior ◽  
Viscosity Index ◽  
Rheological Parameters ◽  
Nano Tio2 ◽  
Flow Behavior Index ◽  
Flow Activation Energy ◽  
Degradation Degree

Rheological properties of blend spinning solution of sodium alginate and TiO2 nanoparticles (SA/nano-TiO2) were investigated. The rheological parameters, structural viscosity index (Δη) and flow activation energy (Eη) of spinning solutions were calculated. The results reported that the blend spinning solutions were non-newtonian fluids. The apparent viscosity, consistency index (k) and Eη increased with increasing nano-TiO2 content in SA spinning solution, but the degradation degree of apparent viscosity decreased, flow behavior index (n) only slightly decreased and the Δη had no significantly change. The apparent viscosity (ηa) of spinning solutions could be regulated by changing temperature under 50oC. Blend spinning solution had good stability and practical applicability.

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