The Rheological Behaviors of Nylon610 and Nylon610/Montmorillonite Nanocomposites

2011 ◽  
Vol 183-185 ◽  
pp. 1726-1730 ◽  
Author(s):  
Qian Wang ◽  
Cheng Shen Zhu ◽  
Ping Du ◽  
Su Qin He
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Apparent Viscosity ◽  
Effect Of Temperature ◽  
Pseudoplastic Fluid ◽  
Rheological Behaviors ◽  
Lower Shear ◽  
Lower Shear Rate ◽  
Montmorillonite Nanocomposites

The rheological behaviors of nylon610 and nylon610/montmorillonite nanocomposites had been studied by means of HAAKE-Ⅱrheometer. The results showed that nylon610 and nylon610/montmorillonite composites were pseudoplastic fluid. The non-Newtonian indexes, which were in the range of 0.49～0.82 at differern temperatures, decreased with the addition of montmorillonite. What is more, the apparent viscous activation energy decreased, which showed the effect of temperature on apparent viscosity of the nanocomposites was weaker than that of pure nylon610, apparent viscosity increased with the increase of montmorillonite, especially at the lower shear rate.

Flow Behaviors of High Acyl Gellan Aqueous Solutions as Affected by Temperature, and Calcium and Gellan Concentrations

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Yiqun Huang ◽  
Pawan Singh Takhar ◽  
Juming Tang ◽  
Barry G Swanson
Keyword(s):  
Shear Rate ◽  
Aqueous Solutions ◽  
Apparent Viscosity ◽  
Flow Resistance ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Rheological Behaviors ◽  
Low Concentrations ◽  
Influence Of Temperature On

Rheological behaviors of high acyl (HA) gellan are not well understood partially because of its relatively late commercialization compared to low acyl gellan. The objective of this study was to investigate the effect of temperature (5-30 °C), calcium (0, 1 and 10 mM) and gellan concentrations (0.0044-0.1000% w/v) on the flow behaviors of high acyl gellan aqueous solutions using rheological tests. Gellan solutions with 0 or 1 mM added Ca++ exhibited shear thinning behavior at gellan concentrations above 0.0125%. The influence of temperature on apparent viscosity (shear rate, 100 s-1) of gellan solutions can be described with an Arrhenius relationship. The apparent viscosity of gellan solution at low concentrations was more sensitive to temperature changes. The addition of Ca++ led to a decrease in flow resistance for a dilute gellan solution (<0.0125%), but an increased resistance for a relatively concentrated gellan solution (>0.0125%).

Research on the Rheological Properties of Polyphenylene Sulfide (PPS) Resin

2011 ◽  
Vol 332-334 ◽  
pp. 949-954
Author(s):  
Peng Wei Xiang ◽  
Rui Ping Zhang ◽  
Mei Niu ◽  
Xue Ping Guo ◽  
Qi Rong Bai
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Viscous Flow ◽  
Apparent Viscosity ◽  
Viscosity Index ◽  
Polyphenylene Sulfide ◽  
Pseudoplastic Fluid ◽  
Temperature Shear ◽  
The Impact ◽  
Flow Experiments

Using capillary rheometer to study PPS temperature, shear rate, activation energy of viscous flow. Experiments show that with the increase of shear rate, apparent viscosity decreased. As the apparent viscosity is affected by temperature, so when the temperature increased, the apparent viscosity also decreased. It also indicates that the higher the shear rate comes, the lower the impact of temperature on the apparent viscosity is. As the temperature increased, non-Newtonian index (n) increased and tended to 1, PPS melt is pseudoplastic fluid. The activation energy of viscous flow of PPS decreased with the increasing of the shear rate. In addition, with the increasing of temperature, structural viscosity index felt regularly.

Investigation on the Rheological Behavior of Polyamide6/Montmorillonite Nanocomposites by Reactive Extrusion

2011 ◽  
Vol 233-235 ◽  
pp. 1998-2001 ◽  
Author(s):  
Ming Zhao ◽  
Xiao Zhong Lu ◽  
Kai Gu ◽  
Xiao Min Sun ◽  
Chang Qing Ji
Keyword(s):  
Activation Energy ◽  
Shear Stress ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Reactive Extrusion ◽  
Shear Thinning ◽  
Experimental Results ◽  
Montmorillonite Nanocomposites

The rheological behavior of PA6/montmorillonite(MMT) by reactive extrusion was investigated using cone-and-plate rheometer. The experimental results indicated that PA6/MMT exhibited shear-thinning behavior. The shear stress of both neat PA6 and PA6/MMT increased with the increase in the shear rate. The reduction of the viscous activation energy with the increase of shear stress reflected PA6/MMT can be processed over a wider temperature.

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.

scholarly journals The Effect of the Operating Conditions on the Apparent Viscosity of Crude Palm Oil During Oil Clarification

1970 ◽  
Vol 5 (1) ◽  
Author(s):  
Sulaiman Al-Zuhair, Mirghani I. Ahmed and Yousif A. Abakr
Keyword(s):  
Shear Rate ◽  
Boundary Conditions ◽  
Palm Oil ◽  
Apparent Viscosity ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
Optimum Operating ◽  
Crude Palm Oil ◽  
Different Boundary Conditions ◽  
Rotary Viscometer

This paper discusses the apparent viscosity of crude palm oil, using rotary viscometer, under different boundary conditions. It was experimentally shown that the apparent viscosity of palm oil drops with increasing of the shear rate and the temperature.  However, the effect of temperature on the viscosity tends to fade at temperatures beyond 80 oC.  A correlation between the apparent viscosity of crude palm oil and the operating conditions was developed. This correlation can be used in design of crude palm oil settlers and in determining the optimum operating conditions.Key Words:  Crude palm oil, apparent viscosity, shear rate, modelling, separation 

Effects of Amines on Chemical and Physical Behaviors of Viscous Precursor Sols to Indium Gallium Zinc Oxide

2013 ◽  
Vol 1547 ◽  
pp. 123-128 ◽  
Author(s):  
Nobuko Fukuda ◽  
Shintaro Ogura ◽  
Ken-ichi Nomura ◽  
Hirobumi Ushijima
Keyword(s):  
Zinc Oxide ◽  
Shear Rate ◽  
Metal Oxides ◽  
Boiling Point ◽  
Indium Gallium Zinc Oxide ◽  
High Concentration ◽  
Lower Shear ◽  
Metal Nitrates ◽  
Lower Shear Rate ◽  
Indium Gallium

ABSTRACTWe synthesized viscous precursors to indium gallium zinc oxide (IGZO) using three kinds of alcoholamines, ethanolamine (EA), diethanolamine (DEA), and triethanolamine (TEA), by a simple process. The viscous precursors are obtained just by vigorous stirring of alcoholamine and urea in an aqueous solution containing the metal nitrates during heating at 150-160 °C. The precursor containing EA (EA-precursor) is a pale-orange suspension containing aggregates of the metal hydroxides and shows pseudoplastic flow. The precursors containing DEA (DEA-precursor) and TEA (TEA-precursor) are transparent pale-yellow and dark-orange sols, respectively. They give Newtonian flow in the lower shear rate and pseudoplastic flow in the higher shear rate. Higher concentration of metal salts leads to higher viscosity of the precursors. According to thermogravimetry-differential thermal analysis (TG-DTA) for the EA- and DEA-precursors, evaporation of alcoholamine occurs at around each boiling point and subsequently formation of metal oxides occur at around 300 °C. In the case of the TEA-precursor, formation of metal oxides occurs before pyrolysis of TEA attributed to the higher boiling point of TEA. The thin IGZO film, which is prepared by spin-coating of the diluted DEA-precursor and subsequent sintering at 450 °C for 30 min, shows 0.02 cm2 ·V-1s-1 of the mobility and 10-5 of the on/off ratio. The highly viscous DEA-precursor containing high concentration of metal ions allows patterning in an area of 100 cm2 onto a surface of a silicon wafer with screen printing.

Investigation on the Rheological Behavior of PA1010/POE/OMMT Nanocomposites

2012 ◽  
Vol 482-484 ◽  
pp. 2582-2586
Author(s):  
Yan Fei Zhang ◽  
Ying Chun Li ◽  
Guo Sheng Hu
Keyword(s):  
Activation Energy ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Experimental Results ◽  
Shearing Stress ◽  
Pseudoplastic Fluid ◽  
High Shearing

The rheological behavior of PA1010/POE/OMMT nanocomposites was studied by using XLY-Ⅱ rheometer. The curves of lgτω～lgγ’ω, lgηa～lgγ’ω, lgηa～1/T were obtained. The experimental results showed that PA1010/POE/OMMT nanocomposites were pseudoplastic fluid. The apparent viscosity of the blends reduced with the increase of the shearing stress．Compared with PA1010/POE blends, the addition of OMMT increased the apparent viscosity. The viscous activation energy of PA1010/POE/OMMT blends declined as the increase of shearing stress, which indicated that the PA1010/POE/OMMT blends could be processed over a wide temperature at a high shearing stress.

Platelet Adherence and Detachment - In What Ways Is Surface-Bound Albumin Different from Surface-Bound Fibrinogen?

1986 ◽  
Vol 55 (02) ◽  
pp. 184-188 ◽  
Author(s):  
I A Feuerstein ◽  
J Kush
Keyword(s):  
Shear Rate ◽  
Human Albumin ◽  
Human Fibrinogen ◽  
Lower Shear ◽  
Platelet Adherence ◽  
Lower Shear Rate ◽  
Glass Tubes ◽  
Protein Coatings ◽  
First Contact ◽  
Measurement Area

SummaryThe adhesion and detachment of platelets on surface-bound albumin and surface-bound fibrinogen were studied. Fluorescent video-microscopy of platelets labelled with mepacrine was used to provide continuous information. Glass tubes (I.D. 1.3 mm) were precoated with either human albumin or human fibrinogen before exposure to a suspension of washed platelets and red cells. Observations were made 0.5 cm from the tube’s entrance over a 1370 μm2 portion of lumen. The rate at which cells leave the measurement area and the percent of initially attaching cells which leave are independent of protein coating but increase with flow rate. The percent of initially attaching platelets which permanently adhere is equal for both protein coatings but the pathways leading to this result can be different. For the lower shear rate studied, 80 s−1, the percent of cells which permanently adhere on first contact is less for albumin than for fibrinogen; the percent of initially attaching cells which adhere and then move before permanent adhesion is greater for albumin. The mechanism of detachment and reattachment leads to the equality of the overall adhesion efficiencies for the two protein coatings at 80 s−1. For the higher shear rate studied, 456 s−1 the adhesion pathways for both coatings were the same.

A unified description of gravity- and kinematics-induced segregation forces in dense granular flows

2021 ◽  
Vol 925 ◽  
Author(s):  
Lu Jing ◽  
Julio M. Ottino ◽  
Richard M. Lueptow ◽  
Paul B. Umbanhowar
Keyword(s):  
Shear Rate ◽  
Scaling Law ◽  
Free Surface Flows ◽  
Gradient Term ◽  
Lower Shear ◽  
Particle Size Ratio ◽  
Lower Shear Rate ◽  
Flow Configurations ◽  
Unified Description ◽  
Rate Gradient

Particle segregation is common in natural and industrial processes involving flowing granular materials. Complex, and seemingly contradictory, segregation phenomena have been observed for different boundary conditions and forcing. Using discrete element method simulations, we show that segregation of a single particle intruder can be described in a unified manner across different flow configurations. A scaling relation for the net segregation force is obtained by measuring forces on an intruder particle in controlled-velocity flows where gravity and flow kinematics are varied independently. The scaling law consists of two additive terms: a buoyancy-like gravity-induced pressure gradient term and a shear rate gradient term, both of which depend on the particle size ratio. The shear rate gradient term reflects a kinematics-driven mechanism whereby larger (smaller) intruders are pushed toward higher (lower) shear rate regions. The scaling is validated, without refitting, in wall-driven flows, inclined wall-driven flows, vertical silo flows, and free-surface flows down inclines. Comparing the segregation force with the intruder weight results in predictions of the segregation direction that match experimental and computational results for various flow configurations.

Properties of EPDM/PP thermoplastic vulcanizates produced by an intermeshing-type internal mixer comparing with a co-rotating twin-screw extruder

2019 ◽  
Vol 39 (2) ◽  
pp. 143-151
Author(s):  
Wattana Teppinta ◽  
Banja Junhasavasdikul ◽  
Nattapong Nithi-Uthai
Keyword(s):  
Shear Rate ◽  
Elastic Recovery ◽  
Mechanical Energy ◽  
Cross Linking ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Lower Shear ◽  
Twin Screw ◽  
Lower Shear Rate ◽  
Internal Mixer

Abstract A unique technology for producing thermoplastic vulcanizate (TPV) has been developed using an intermeshing-type internal mixer (ITM). TPV produced by the ITM was compared with that produced using a co-rotating twin screw extruder (Co-TSE) to assess the former’s commercial possibilities. TPV, originating from ethylene-propylene-diene monomer (EPDM) and polypropylene (PP), was produced by both machines with equal filled volumes, same shear rate, and same specific mechanical energy. Results indicate that ITMs can be used to produce TPV with mechanical properties comparable to those of TPV produced by Co-TSE. TPV can be produced with a lower shear rate with ITM compared to Co-TSE. A long residence time can be maintained in the mixing chamber of the ITM, allowing high conversion of the cross-linking reaction and resulting in better elastic recovery properties due to the higher cross-linking density. However, this resulted in higher viscosity of TPV produced by ITM.

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