Effects of Concentration and Temperature on Rheological Properties of Mixture of HPMC and CMC Solutions

2013 ◽  
Vol 787 ◽  
pp. 792-797
Author(s):  
Qing Yong Li ◽  
Jun Ye ◽  
Jian Xiong
Keyword(s):  
Rheological Properties ◽  
Arrhenius Equation ◽  
Loss Modulus ◽  
Flow Activation Energy ◽  
Shear Rates ◽  
Shear Thinning Fluids ◽  
Dynamic Rheological Properties ◽  
Flow Activation ◽  
Dominant Property ◽  
Power Law Equation

This work was designed to study the rheologicl properties of mixture of HPMC and CMC solutions because their rheologicl properties are very important in no matter food or pharmaceutical industry processing operations. Experiments were performed at different mixture ratios, shear rates and temperatures. The static and dynamic rheological properties tests were measured through the rheometer AR-550 and were investigated by using Power Law equation, Cross equation and Arrhenius equation. The results showed that the HPMC-CMC solutions behaved as typical Non-Newtonian shear-thinning fluids and had stronger non-Newtonian nature. With the concentration(CMC)increasing, consistency coefficient K, Zero Shearing Viscosity η0,viscous flow activation energy E, storage modulus G and loss modulus G all increased but decreased with the temperature increasing, except for Non-Newtonian index n. And viscosity was the dominant property in the mixture of HPMC-CMC solutions.

Effect of stretching speed on morphologies and properties of in situ microfibrillar POE/PLA composites

2020 ◽  
pp. 089270572093917
Author(s):  
Jing Sun ◽  
Anrong Huang ◽  
Shanshan Luo ◽  
Min Shi ◽  
Heng Luo ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Rheological Properties ◽  
Loss Modulus ◽  
Weight Ratio ◽  
Poly Lactic Acid ◽  
Electron Microscopic ◽  
Dynamic Rheological Properties ◽  
Scanning Electron Microscopic ◽  
Ethylene Octene Copolymer

In situ microfibrillar ethylene–octene copolymer (POE)/poly(lactic acid) (PLA) composites (MFCs) with different phase morphologies were prepared by controlling the stretching speed and maintaining the weight ratio of POE/PLA of 80/20. Four different stretching speeds were employed to study the effect of PLA microfibrillar morphology on tensile, crystalline, and rheological properties of MFCs. Scanning electron microscopic images revealed that the morphology of PLA phase was strongly influenced by stretching speed. MFCs with highest aspect ratio and smaller diameter of PLA microfibrils were obtained with a stretching speed of 60 rpm. The PLA microfibrils with high aspect ratio had the best reinforcement effect on MFCs. The dynamic rheological properties indicated that the MFCs achieved higher storage modulus and loss modulus at the stretching speed of 60 rpm.

Rheological Behavior of Blend Spinning Solution of Sodium Alginate and Carbon Black

2011 ◽  
Vol 332-334 ◽  
pp. 268-274
Author(s):  
Li Wen Tan ◽  
Quan Ji ◽  
Jian Jun Zhang ◽  
Feng Jun Wang ◽  
Feng Yu Quan ◽  
...  
Keyword(s):  
Carbon Black ◽  
Sodium Alginate ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Viscosity Index ◽  
Flow Activation Energy ◽  
Shear Rates ◽  
Swell Ratio ◽  
Flow Activation ◽  
Large Flow

Rheological properties of blend spinning solution of sodium alginate and carbon black (SA/CB) were investigated. The results reported that blend spinning solutions were non-newtonian fluids. The apparent viscosity and structural viscosity index increased with increasing CB content in SA spinning solution, but the non-newtonian index decreased, both demonstrated the blend solution was sensitive to shear rates. Blend spinning solution with 6% CB had large flow activation energy (Eη), so the temperature must be controlled exactly in spinning. Temperature had similar impact on sample spinning solutions: the apparent viscosity decreased when it increased. Study on dynamic rheological behavior shows SA/CB blend spinning solutions had greater die swell ratio and worse flowability than pure SA solution, but the flowability of blend solutions could be regulated by changing temperature.

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.

Rheological Properties of PTT/POE/OMMT Composites

2010 ◽  
Vol 150-151 ◽  
pp. 834-837
Author(s):  
Ming Tao Run ◽  
Li Jie Guo ◽  
Qing Chang Zhang ◽  
Yu Zhong ◽  
Qing Han ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Solution Method ◽  
Mixed Solution ◽  
Melt Blending ◽  
Capillary Rheometer ◽  
Flow Activation Energy ◽  
Twin Screw ◽  
Flow Activation ◽  
Trimethylene Terephthalate ◽  
Poly Ethylene

Poly(ethylene-octene)(POE) and organic montmorillonite(OMMT) acting respectively as the toughening agents and reinforcing agents, were used to prepare nanocomposites with Poly(trimethylene terephthalate)(PTT) in order to modify PTT, and the rheological properties of these composites were investigated by using capillary rheometer instrument. The OMMT used in composite was prepared by intercalating triphenyl phosphate (TPP) into MMT by mixed solution method. PTT/POE/OMMT nanocomposites were prepared by melt blending in twin-screw corotating extruder. Rheological results show that PTT/POE/OMMT composite melt was pseudo-plastic liquid and the pseudo-plasticity of the melt was decreased with increasing OMMT content for the strong interface interactions between OMMT and polymer molecular chains. The melt apparent viscosity was increased with increasing OMMT content. The flow activation energy results suggested that the composite melt having more OMMT components is more sensitive to the change of temperature.

Study on Themal and Rheological Properties of POM

2012 ◽  
Vol 487 ◽  
pp. 192-197
Author(s):  
Zhi Hong Guo ◽  
Zhen Xi Wen ◽  
Qing Yan Xu ◽  
Yuan Tian ◽  
Gao Qiu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Shear Rate ◽  
Rheological Properties ◽  
Chemical Structure ◽  
Decomposition Temperature ◽  
Excellent Performance ◽  
Melt Temperature ◽  
Flow Activation Energy ◽  
Rate Range ◽  
Flow Activation

Polyoxymethylene is a linear polymer with excellent performance due to its chemical structure and high crystallinity. The thermal and rheological properties of POM are investigated in this paper. Experimental results indicate that the melting point and decomposition temperature of POM are about 162 °C and 266 °C respectively. POM melt is a non-Newtonian fluid, the apparent viscosity gradually decreased with the increase of shear rate, showing a typical shear-thinning behavior. Non-Newtonian index increased from 0.53 to 0.61 as the melt temperature increased from 190 °C to 230 °C. The flow activation energy of POM melt is between 11.36 and 24.90 kJ/mol within the shear rate range of 90~2500s -1.

Results on the Correlation between Molecular Architecture and Rheological Parameters of Metallocene-Catalyzed Polyethylenes

2012 ◽  
Vol 550-553 ◽  
pp. 736-741
Author(s):  
Peng Peng Li ◽  
Shi Yuan Yang ◽  
Shan Xue
Keyword(s):  
Activation Energy ◽  
Loss Modulus ◽  
Structural Parameters ◽  
Shear Thinning ◽  
Short Chain ◽  
Rheological Parameters ◽  
Molecular Architecture ◽  
Chain Branching ◽  
Flow Activation Energy ◽  
Flow Activation

Dynamic rheological results of 17 commercial and noncommercial metallocene-catalyzed polyethylenes, such as shear thinning index(SHI), modulus of crossover point of store modulus and loss modulus (Gco) and flow activation energy(Ea), are presented. The effects of molecular weight distribution(MWD), and degree of short chain branching (SCB) determined by gel permeation chromatography (GPC) and FTIR, were analyzed. Plots of SHI versus MWD revealed the influence of branching level on the shear thinning behavior of polyethylenes. Gcowas observed scaling with MWD for metallocene-catalyzed polyethylenes and the correlation between them was generated by MWD=193378*Gco. Correlation between flow activation energy measured by dynamic temperature sweep at low frequency and short chain branch-0.9038was also established for metallocene polyethylenes as SCB=7*10-8*Ea6.024. Thus, an alternative single rheological method, based on the effect of molecular structural parameters on dynamic rheological behaviors, was proposed to evaluate the polydispersity and short chain branching of metallocene-catalyzed polyethylene.

Rheological Properties of Anghouzeh Gum

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Jafar Milani ◽  
Babak Ghanbarzadeh ◽  
Gisoo Maleki
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
Intrinsic Viscosity ◽  
Loss Modulus ◽  
Gel Permeation Chromatography ◽  
Low Frequencies ◽  
Shear Rates ◽  
Frequency Sweep Test ◽  
Alcoholic Extraction ◽  
Very High Frequencies

Abstract Rheological properties of anghouzeh gum, the exudate polysaccharides of Ferula asafoetida, was investigated. For this purpose, anghouzeh gum was extracted from crude exudate by alcoholic extraction with 90% ethanol. The molecular weight of the anghouzeh gum was determined by gel permeation chromatography (GPC). Anghouzeh gum had smaller molecular weight and lower intrinsic viscosity than arabic gum. The intrinsic viscosity was determined by extrapolating Huggins and Kraemer equations to zero concentration. The obtained intrinsic viscosity was 0.213 dl/g. The viscosity of the anghouzeh gum solution was very close to that of albizia gum. Newtonian plateau was seen in low shear rates while a weak shear thinning behavior was observed in higher shear rates. The frequency sweep test showed that in 3% gum solutions the loss modulus (G") was greater than the storage modulus (G') at low frequencies and then it became lower than G' with increasing of frequency. However, critical point was located at very high frequencies.

Electrical conductivity and rheological properties of carbon black based conductive polymer composites prior to and after annealing

2021 ◽  
pp. 096739112110012
Author(s):  
Qingsen Gao ◽  
Jingguang Liu ◽  
Xianhu Liu
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Percolation Threshold ◽  
Rheological Properties ◽  
Network Formation ◽  
Loss Modulus ◽  
Conductive Polymer ◽  
Complex Viscosity ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold

The effect of annealing on the electrical and rheological properties of polymer (poly (methyl methacrylate) (PMMA) and polystyrene (PS)) composites filled with carbon black (CB) was investigated. For a composite with CB content near the electrical percolation threshold, the formation of conductive pathways during annealing has a significant impact on electrical conductivity, complex viscosity, storage modulus and loss modulus. For the annealed samples, a reduction in the electrical and rheological percolation threshold was observed. Moreover, a simple model is proposed to explain these behaviors. This finding emphasizes the differences in network formation with respect to electrical or rheological properties as both properties belong to different physical origins.

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.

Impact of high-pressure homogenization on the microstructure and rheological properties of citrus fiber

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dianbin Su ◽  
Xin-Di Zhu ◽  
Yong Wang ◽  
Dong Li ◽  
Li-Jun Wang
Keyword(s):  
Particle Size ◽  
High Pressure ◽  
Rheological Properties ◽  
Binding Capacity ◽  
Loss Modulus ◽  
High Pressure Homogenization ◽  
Carreau Model ◽  
Hydration Properties ◽  
Water Binding ◽  
Water Holding

Abstract Citrus fiber dispersion with different concentrations (5–25 g/kg) was treated by high-pressure homogenization (90 and 160 MPa) for two cycles. The particle size distribution, hydration properties of powders, morphology and rheological measurements were carried out to study the microstructure and rheological properties changes by high-pressure homogenization (HPH). In conclusion, the HPH can reduce the particle size of fiber, improve the water holding capacity and water binding capacity. Furthermore, fiber shape can be modified from globular cluster to flake-like slices, and tiny pores can be formed on the surface of citrus fiber. The apparent viscosity, storage modulus and loss modulus were increased by HPH whereas the activation energy was reduced. The Hershcel–Bulkley model, Carreau model and Power Law mode were selected to evaluate the rheological properties.

Sign in / Sign up

Export Citation Format

Share Document