Rheological properties of carbon mixes at low shear rates using a capillary rheometer

Carbon ◽  
1973 ◽  
Vol 11 (5) ◽  
pp. 437-440 ◽  
Author(s):  
G. Bhatia
Keyword(s):  
Rheological Properties ◽  
Capillary Rheometer ◽  
Shear Rates ◽  
Low Shear

Effect of Film Thickness on the Rheological Properties of Asphalts in Contact with Aggregate Surface

1998 ◽  
Vol 1638 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Shin-Che Huang ◽  
Jan F. Branthaver ◽  
Raymond E. Robertson ◽  
Sang-Soo Kim
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Rheological Properties ◽  
Thickness Effect ◽  
Asphalt Binders ◽  
Shear Rates ◽  
Service Environment ◽  
Asphalt Mix ◽  
Plate Geometry ◽  
Low Shear

The effect of the interaction between aggregate and asphalt on asphalt mix properties has been a subject of many studies. However, studies using compacted mixtures cannot isolate the pure effects of the asphalt-aggregate interactions, while studies using mixtures of asphalt and fines cannot determine the asphalt rheology at the interface. In this study, direct measurement of asphalt rheology at the interface is investigated using the sliding plate geometry with machined aggregate plates. Significant differences in the behavior of asphalts in contact with aggregate plates have been observed, especially at low shear rates. One asphalt shows substantial aggregate surface-induced structuring, while another asphalt shows essentially none. In addition, the film thickness effect on the rheological properties of asphalt binders and asphalt aggregate mixtures was investigated. The results strongly show that thin films of asphalt on an aggregate surface have substantially changed rheological properties that are asphalt composition–dependent, and that asphalts that are graded alike as bulk materials do not have the same rheological properties as thin films, in this service environment.

Rheological Properties of Multi-Block Associative Polyelectrolytes Obtained by Nitroxide-Mediated Solution Polymerization

2014 ◽  
Vol 1613 ◽  
pp. 143-149
Author(s):  
Alejandro Coronado ◽  
Areli I. Velazquez ◽  
Enrique J. Jiménez
Keyword(s):  
Rheological Properties ◽  
Creep Compliance ◽  
Viscoelastic Behavior ◽  
Degree Of Polymerization ◽  
Shear Rates ◽  
Linear Response Regime ◽  
Copolymer Structure ◽  
Rheological Experiments ◽  
Polymer Bearing ◽  
Low Shear

ABSTRACTA multi-block associative polyelectrolyte based on poly(methacrylic acid-ra-styrene) [MAA-S] and poly(octadecyl methacrylate) [ODMA] was synthesized through stepwise nitroxide-mediated solution polymerizations. The obtained polymer has a heptablock copolymer structure, alternating MAA-S as hydrophilic blocks (theoretical degree of polymerization [DPT] of 250), and ODMA as hydrophobic blocks (DPT = 15). Rheological properties, in the linear-response regime, of aqueous solutions (polymer content = 1.5 wt.%) were studied as a function of the amount of blocks on the polymer using steady-shear and creep-compliance experiments. Rheological experiments demonstrate that the viscoelastic behavior of the polymer bearing an ODMA block in terminal position greatly differs from that of the polymer with MAA-S block terminations. The former behaves as a newtonian fluid on a wider range of shear rates than the latter, which exhibit a shear-thinning behavior, even at low shear rates, independently of the molecular weight and number of blocks.

Effect of Aggregation on the Rheological Properties of Carbon Nanotube Dispersions

2006 ◽  
Vol 953 ◽  
Author(s):  
Sameer Sharad Rahatekar ◽  
Jeffrey W Gilman ◽  
K K Koziol ◽  
Simon Butler ◽  
James A Elliott ◽  
...  
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Optical Observations ◽  
Interconnected Network ◽  
Shear Rates ◽  
High Shear Rates ◽  
Suspension Viscosity ◽  
The Matrix ◽  
Viscosity Enhancement ◽  
Low Shear

ABSTRACTIn this pape effect of nanotube aggrates on the rheological properties of multiwall carbonanntube abd epoxy suspension in epoxy resin.The base epoxy resin was found to be essentially Newtonian, and the progressive incorporation of nanotubes enhanced the low shear rate viscosity of the suspension by nearly two decades. At higher shear rates, the suspension viscosity asymptotically thinned to the viscosity of the matrix alone. The low shear rate viscosity enhancement was correlated with the optical observations of interconnected aggregates of carbon nanotubes, which themselves were induced by the low shear conditions. Intermediate shear rates resulted in a reduction in the size of the aggregates. High shear rates appeared to cause near complete dispersal of the aggregates. From these results it is conjectured that for this suspension, shear thinning is connected with the breaking of the interconnected network between aggregates of nanotubes, and not by nanotube alignment.

Influence of Maleation of Ground Rubber Tyre (GRT) on the Thermorheological behaviour of Thermoplastic Elastomers Based on Ethylene Propylene Diene Rubber, GRT and Ethylene-co-acrylic acid

2002 ◽  
Vol 10 (6) ◽  
pp. 427-432 ◽  
Author(s):  
Amit K. Naskar ◽  
S. K. De ◽  
Anil K. Bhowmick
Keyword(s):  
Mechanical Analysis ◽  
Thermoplastic Elastomers ◽  
Capillary Rheometer ◽  
Melt Fracture ◽  
Shear Rates ◽  
Ground Rubber ◽  
High Shear Rates ◽  
The Matrix ◽  
Diene Rubber ◽  
Low Shear

The thermorheological behaviour of thermoplastic elastomeric blends based on both ground rubber tyre (GRT) and maleic anhydride grafted GRT (m-GRT) has been studied. The blend composition based on m-GRT exhibits a higher melt viscosity than the corresponding control blend based on GRT. The former exhibits lower die swell and less melt fracture at low shear rates than the latter, when extruded at 180°C through a capillary rheometer. At high shear rates, however, both the blends exhibit melt fracture. There is apparently some interaction between m-GRT and the matrix, which is evident from dynamic mechanical analysis. The m-GRT causes a significant lowering in tanδ at temperatures higher than the Tg of the blend.

scholarly journals Rheological Properties of Wood–Plastic Composites by 3D Numerical Simulations: Different Components

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 417
Author(s):  
Xingcong Lv ◽  
Xiaolong Hao ◽  
Rongxian Ou ◽  
Tao Liu ◽  
Chuigen Guo ◽  
...  
Keyword(s):  
Flow Field ◽  
Rheological Properties ◽  
Wood Fiber ◽  
Velocity Shear ◽  
Wood Plastic Composites ◽  
Shear Rates ◽  
Plastic Composites ◽  
Power Law Fluids ◽  
Field Information ◽  
Computational Fluid Dynamics Cfd

The rheological properties of wood–plastic composites (WPCs) with different wood fiber contents were investigated using a rotational rheometer under low shear rates. The flow field information was analyzed and simulated by Ansys Polyflow software. The results showed that the WPCs with different wood fiber contents behaved as typical power-law fluids. A higher wood fiber content increased the shear thinning ability and pseudoplasticity of the WPCs. The pressure, velocity, shear rate, and viscosity distributions of the WPC during extrusion could be predicted by computational fluid dynamics (CFD) Ansys Polyflow software to explore the effects of different components on the flow field of WPCs.

scholarly journals Rheological properties of hydroxypropylmethyl cellulose/sodium dodecylsulfate mixtures

2014 ◽  
Vol 79 (4) ◽  
pp. 457-468 ◽  
Author(s):  
Jaroslav Katona ◽  
Sandra Njaradi ◽  
Verica Sovilj ◽  
Lidija Petrovic ◽  
Brankica Marceta ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Sodium Dodecylsulfate ◽  
Shear Thinning ◽  
Cellulose Ether ◽  
Flow Profile ◽  
Hydroxypropylmethyl Cellulose ◽  
Shear Rates ◽  
Newtonian Liquids ◽  
Shear Induced Structure ◽  
Induced Structure

Rheological properties of mixtures of hydroxypropylmethyl cellulose (HPMC), a nonionic associative cellulose ether, and sodium dodecylsulfate (SDS), an anionic surfactant, were investigated by viscosity measurements performed at different shear rates (0.1-6000 s-1). HPMC/SDS mixtures containing different concentrations of SDS (CSDS=0.00-3.50 % w/w) and HPMC concentrations which corresponded to the overlap parameter c/c*=3, 6, and 12 were prepared. All HPMC/SDS mixtures were found to be shear-thinning when examined in a low-end-to mid-range of the applied shear rates. The degree of shear-thinning, n, and viscosity of the mixtures were influenced by composition of HPMC/SDS mixtures and HPMC-SDS complex formation. The changes in n ranged from values typical for highly shear thinning to almost perfectly Newtonian liquids, and were more pronounced as c/c* was increased from 3 to 6 and 12. A change in flow profile and a buildup of the first normal stress difference (N1) was observed in HPMC/SDS mixtures with c/c*=6 and 12 and CSDS 0.55-1.00 % and 0.55-2.50 %, respectively, when a critical shear rate, crit. was exceeded, suggesting that a shear-induced structure formation in the mixtures took place.

Sign in / Sign up

Export Citation Format

Share Document