Rheological Properties of Three Solutions. Part I. Non‐Newtonian Viscosity, Normal Stresses, and Complex Viscosity

1967 ◽  
Vol 11 (2) ◽  
pp. 159-179 ◽  
Author(s):  
J. D. Huppler ◽  
E. Ashare ◽  
J. A. Holmes
Keyword(s):  
Rheological Properties ◽  
Complex Viscosity ◽  
Normal Stresses ◽  
Three Solutions ◽  
Newtonian Viscosity

Rheological Properties of Three Solutions. Part II. Relaxation and Growth of Shear and Normal Stresses

1967 ◽  
Vol 11 (2) ◽  
pp. 181-204 ◽  
Author(s):  
J. D. Huppler ◽  
I. F. Macdonald ◽  
E. Ashare ◽  
T. W. Spriggs ◽  
R. B. Bird ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Normal Stresses ◽  
Three Solutions

Rheological Studies of Dynamically Vulcanized and Mechanical Blends of Polypropylene and Ethylene-Propylene Rubber

1995 ◽  
Vol 68 (5) ◽  
pp. 728-738 ◽  
Author(s):  
Peter K. Han ◽  
James L. White
Keyword(s):  
Shear Viscosity ◽  
Liquid Crystalline ◽  
Complex Viscosity ◽  
Normal Stresses ◽  
State Structure ◽  
Newtonian Viscosity ◽  
Zero Shear Viscosity ◽  
Flexible Chain ◽  
Ethylene Propylene ◽  
Yield Value

Abstract An experimental study is presented of the rheological properties of (i) polypropylene, (ii) a commercial polypropylene/ethylene-propylene terpolymer a dynamically vulcanized blend (PP/EDPM-TPE) and (iii) a mechanical blend of a polypropylene and an ethylene-propylene copolymer. The polypropylene behaves as a typical flexible chain thermoplastic exhibiting a zero shear viscosity and higher shear rate non-Newtonian viscosity, well defined normal stresses, an elongational viscosity three times the zero shear viscosity, and an equality of the shear viscosity and the complex viscosity (Cox-Merz Rule). The PP/EPM-TPE exhibits an apparent yield value in shear flow, unmeasurable normal stresses and a complex viscosity which is much greater than the shear viscosity. This is behavior similar to that of particle filled compounds, block copolymers and liquid crystalline thermoplastics and suggests a material with a rest state structure. The behavior of the PP/EPM mechanical blend is intermediate.

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.

Calcium Carbonate Reinforced Polypropylene Nanocomposites: Effect of Nano-Filler Loadings on the Melt Rheological Properties

2018 ◽  
Vol 777 ◽  
pp. 168-172 ◽  
Author(s):  
Achmad Chafidz ◽  
Ajeng Y.D. Lestari ◽  
Lucky Setyaningsih ◽  
Widi Astuti ◽  
Muhammad Rizal
Keyword(s):  
Rheological Properties ◽  
Complex Viscosity ◽  
Viscosity Data ◽  
Rheological Analysis ◽  
Melt Compounding ◽  
Polypropylene Nanocomposites ◽  
Different Types ◽  
Dispersion State ◽  
Rheological Test ◽  
Fesem Micrographs

In recent years, polymer-based nanocomposites have been investigated by many researchers due to their enhanced properties. Different types of nanomaterials have been used to produce polymer nanocomposites. One of them is nano-CaCO3. In the present work, nano-CaCO3 material reinforced polypropylene (PP) nanocomposites have been fabricated by melt compounding the PP pellets and nano-CaCO3 masterbatch. The effect of four different loadings of nano-CaCO3 (0, 5, 10, 15 wt%) on the melt rheological properties of the nanocomposites has been investigated. The morphology of the nanocomposites was analyzed by a Field Emission Scanning Electron Microscopy (FESEM) to study the dispersion state and distribution of nanoCaCO3 particles in PP matrix. Whereas, the melt rheological behavior of the nanocomposites was analyzed by an oscillatory rheometer. The FESEM micrographs showed that the nano-CaCO3 particles were well dispersed and distributed in the PP matrix. Additionally, the melt rheological analysis results showed that the complex viscosity of all nanocomposites samples were higher than that of neat PP and increased with increasing nano-CaCO3 loadings. Furthermore, the complex viscosity data from the rheological test has been fitted by Carreau-Yasuda equation and it was found to be well fitted.

Physical and rheological properties of biodegradable poly(butylene succinate)/Alfa fiber composites

2020 ◽  
pp. 089270572090409
Author(s):  
Khadidja Arabeche ◽  
Fatiha Abdelmalek ◽  
Laurent Delbreilh ◽  
Latéfa Zair ◽  
Abdelkader Berrayah
Keyword(s):  
Rheological Properties ◽  
Complex Modulus ◽  
Fiber Composite ◽  
Cellulose Fiber ◽  
Complex Viscosity ◽  
Nucleating Agent ◽  
Butylene Succinate ◽  
Molding Method ◽  
Alfa Fibers ◽  
Biodegradable Poly

Biodegradable poly(butylene succinate) (PBS)/Alfa fiber biocomposites were prepared through the compression molding method. Scanning electron microscopy images were acquired to assess the effects of reinforcement and homogenization of mixtures and to determine the characteristics of the microstructure. The rheological properties, melting, and crystallization behavior of neat PBS and its biocomposites were investigated. Regarding the thermal properties, it was observed that the presence of Alfa fibers facilitates the crystallization of the PBS matrix, which suggests that Alfa cellulose fiber acts as a nucleating agent. The rheological analysis suggests that the biocomposites show a better dynamic behavior with the addition of Alfa fibers. Indeed, the incorporation of fibers increased the complex modulus and complex viscosity of the composites. Also, increasing the percentage of fibers in the matrix induces percolation, the shift and change in the slope of Cole–Cole curve of the PBS/Alfa fiber composite compared to that of neat PBS indicate that the PBS microstructure has changed with the addition of fibers. Moreover, the improvement of biocomposites properties is believed to be largely attributable to the homogeneous dispersion of the Alfa fibers within the polymer matrix and also to the strong interfacial interactions between the two constituents.

Preparation of high molecular weight and elastic copolyester by reactive extrusion with diisocyanate compound for laser printing process

2012 ◽  
Vol 32 (3) ◽  
Author(s):  
Hyung-Jin Roh ◽  
Doe Kim ◽  
Dong-Ho Lee ◽  
Keun-Byoung Yoon
Keyword(s):  
Rheological Properties ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Melt Flow Index ◽  
Reactive Extrusion ◽  
Flow Index ◽  
Printing Process ◽  
Laser Printing ◽  
Printing Processes ◽  
Trimethylol Propane

Abstract A branched copolyester was synthesized using dimethyl terephthalate (DMT), 2,2-bis[4-(2-hydroxypropoxy)phenyl]propane, ethylene glycol (EG) and 2-(hydroxymethyl)-2- ethylpropane-1,3-diol (trimethylol propane, TMP). The branched copolyester and p-phenylene diisocyanate (PPDI) were melt extruded to enhance the melt viscosity and elasticity for use as a toner binder in the laser printing process. The effects of PPDI content on melt, thermal and rheological properties of the chain-extended copolyester were investigated. The melt flow index (MI) decreased with increasing amount of PPDI, due to a reaction between the hydroxyl chain end and isocyanate group. The storage modulus, loss modulus and complex viscosity of the chain extended copolyester were higher and the modified Cole-Cole plots revealed the chain extended copolyester to have higher elasticity than that of the branched copolyester. The chain extended copolyester exhibited suitable melt and rheological properties for applications as a toner binder in the laser printing processes.

scholarly journals Effect of Soluble Solids and High Pressure Treatment on Rheological Properties of Protein Enriched Mango Puree

Foods ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 39 ◽  
Author(s):  
Hosahalli Ramaswamy ◽  
Anuradha Gundurao
Keyword(s):  
High Pressure ◽  
Rheological Properties ◽  
Complex Viscosity ◽  
Progressive Increase ◽  
Soluble Solids ◽  
Rheological Parameters ◽  
Pressure Treatment ◽  
Negative Effects ◽  
High Pressure Treatment ◽  
Positive Effects

The effects of high pressure treatment on the rheological properties of protein enriched mango puree were evaluated. In the first part, the original soluble solids in mango puree (28° Brix) was lowered to 26, 23 and 20° Brix, and each was supplemented with 2, 5 and 8% of whey protein to assess the influence of added protein. The samples were then evaluated by dynamic rheology. Pressure treatment resulted in a progressive increase in elastic (G′) and viscous modulii (G″) as well as complex viscosity (η*). Values of G′ were higher than G″ demonstrating that the product behaved more like a gel. Additional tests were carried out by simultaneously varying protein and soluble solids contents, and keeping the total solids at 28%. In this case, the effects of pressure levels and holding times were similar to previous results. However, the positive effects of higher protein were negated by the negative effects of lower soluble solids, resulting in an overall decreasing effect on rheology. The developed models effectively predicted the combined influence of protein and soluble solid concentrations on rheological parameters (R2 > 0.85). Sensory evaluation of 2% and 5% protein supplemented and pressure treated (500 MPa/3 min) mango puree yielded acceptable sensory qualities, resulting in a product with enriched protein content.

Study on Rheological Properties of Polylactic Acid Retardant System

2014 ◽  
Vol 488-489 ◽  
pp. 293-296
Author(s):  
Dong Ze Li ◽  
Xiao Chuan Jia ◽  
Xiu Ping Lu ◽  
Sheng Jia Zhai
Keyword(s):  
Flame Retardant ◽  
Rheological Properties ◽  
Polylactic Acid ◽  
Flow Rate ◽  
Flame Retardants ◽  
Complex Viscosity ◽  
Intumescent Flame Retardant ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Scanning Frequency

A series of polylactic acid (PLA)/IFR composites was prepared by melt blending method.Capillary rheometer and rotary rheometer were applied to investigate the effects of and flame retardants on rheological properties. The results of the rheological test show that the melt flow rate increases with the increasing of content of Intumescent flame retardant. Intumescent flame retardant joined making PLA system flow rate is larger than pure PLA, melt flow rate increases, apparent viscosity decreases, relaxation time decreases, and the complex viscosity decreases gradually with the increase of scanning frequency.

Relationship Between Rheological Properties and Microstructure of Polypropylene/Organic Montmorillonite Nanocomposite Compounded by Twin Screw Extruder

2007 ◽  
Author(s):  
Guo Jiang ◽  
Han-Xiong Huang
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Feeding Rate ◽  
Complex Viscosity ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Property Development ◽  
Organic Montmorillonite ◽  
Twin Screw ◽  
The Relationship

Polypropylene (PP)/organic montmorillonite (OMMT) nanocomposite was compounded in a twin-screw extruder. The objective is to investigate the relationship between rheological properties and microstructure of the nanocompsite. The samples were taken along the screws. Effect of feeding rate on the dynamical rheological property development and microstructure of samples was investigated. The yield stress of nanocomposite was obtained using steady-state shear sweep. The intercalated structure was probed by wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Rheological results showed that the complex viscosity of samples increased along the twin-screw extruder. In addition, with the decrease of feeding rate, the yield stress of nanocomposite increased and MMT was dispersed better in PP matrix. Finally, the relationship between dynamical rheological properties and the dispersed state of MMT was analyzed.

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