A Rheometer for Characterizing Polymer Melts and Suspensions in Shear Creep and Recovery Experiments

Franck, Aly

doi:10.1122/1.549833

Cited by 20 publications

(7 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second instrument was the Rheometries Stress Rheometer (RSR) as described by Franck (1985), using cone and plate geometry with R = 25 mm and cone angle a = 3.8°. This instrument is shear stress controlled and is capable of running shear stress ramps.…”

Section: A Rotational Rheometersmentioning

confidence: 99%

Rheology of extremely shear thickening polymer dispersions^a) (passively viscosity switching fluids)

Laun

Bung

Schmidt

1991

Journal of Rheology

167

View full text Add to dashboard Cite

SynopsisThe flow properties of concentrated polymer dispersions which exhibit extreme shear thickening have been investigated in steady and transient shearing flows using various types of rheometers. A phenomenological characterization based on few fluid parameters is proposed and pertinent test modes for their determination are discussed. The dispersions consist of monodisperse, electrostatically stabilized, solid spherical particles (diameter <0.5 /Lm) dispersed in glycols. They show a reversible steplike viscosity transition of nearly three powers of ten when an apparent critical shear rate 'Ye is exceeded. This jump from a low to a high viscosity state shows typical features of a shear-rate-induced phase transition, including hysteresis and the existence of a metastable low viscosity state above re. The viscosity step can be traced continuously by using stress controlled rheometers. Pronounced fluctuations of the rate of deformation with time are observed at the critical shear rate. The apparent critical shear rate depends on the rheometer geometry. Its change with the gap width in Couette flow and with the radius of circular dies can be interpreted by taking into account a true critical shear rate Yo and a wall slip velocity V S ' Periodic switching to the high viscosity state in oscillatory shear only occurs if both a critical rate amplitude and a critical shear amplitude are reached during the cycle. Applications of these dispersions for simple speed controlling or selectively damping mechanical elements are briefly introduced.

show abstract

Section: A Rotational Rheometersmentioning

confidence: 99%

Rheology of extremely shear thickening polymer dispersions^a) (passively viscosity switching fluids)

Laun

Bung

Schmidt

1991

Journal of Rheology

167

View full text Add to dashboard Cite

show abstract

“…For creep testing the parallel plate geometry of the Rheometrics Stress Rheometer was used. The plates selected had a diameter of 50 mm (Franck, 1985). Gap size was adjusted to 50 km.…”

Section: Creep Measurementsmentioning

confidence: 99%

Effect of Propylene Glycol Alginate and Xanthan Gum on Stability of O/W Emulsions

Yilmazer

Carrillo

Kokini

1991

Journal of Food Science

View full text Add to dashboard Cite

The role of xanthan gum and propylene glycol alginate in stabilizing model oil-in-water salad dressing emulsions has been studied using rheological measurements, particle size analysis and surface tension. Increasing xanthan gum concentration within the gum ratio gave higher viscosity due to formation of aggregates with larger sizes. Propylene glycol alginate (PGA) was surface-active leading to reduction in surface tension of air/water surfaces. Reduction in viscosity was seen in the presence of PGA.

show abstract

“…An instrument where the shear stress and rate of stress change, rather than the rotational speed, are controlled offers advantages. A few such instruments have existed for many years, eg, the Stormer; others have been developed more recently (173)(174)(175)(176)(177)(178). A typical instrument consists of a drag cup motor, a frictionless air-bearing torque shaft, sensors for measuring angular deflection and velocity, and a rotating bob and fixed cup or parallel plates (174)(175)(176)(177).…”

Section: ¼ Kðstress Term/shear Rate Term) ð25þmentioning

confidence: 99%

“…A few such instruments have existed for many years, eg, the Stormer; others have been developed more recently (173)(174)(175)(176)(177)(178). A typical instrument consists of a drag cup motor, a frictionless air-bearing torque shaft, sensors for measuring angular deflection and velocity, and a rotating bob and fixed cup or parallel plates (174)(175)(176)(177). The rotating shaft must be suspended in a frictionless manner to permit measurements at very low stresses.…”

Section: ¼ Kðstress Term/shear Rate Term) ð25þmentioning

confidence: 99%

Rheology and Rheological Measurements

Schöff¹,

Kamarchik

2005

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

This article is concerned with the experimental measurement of rheological properties of both liquids and solids and the principles on which these measurements are based. The flow properties of a liquid are defined by its resistance to flow, ie, viscosity. This concept is defined and discussed in terms of both theoretical flow models and practical consequences. Temperature, thixotropic and other time‐dependent, and concentration effects are covered for dilute polymer solutions, melts, and dispersed systems. Techniques and viscometers for capillary, rotational, and moving‐body measurements are described. The rheological properties of viscoelastic solids are made up of a combination of permanent deformation and recoverable elastic deformation. Additionally, a number of liquids show elastic as well as flow behavior. Also described are additional techniques beyond those indicated for simple solids and liquids, which are needed for complete characterization of mechanical behavior of materials in terms of elasticity and viscoelasticity. Examples of such methods are the dynamic measurement of response to sinusoidal oscillatory motion; the measurement of flow with time after application of stress, ie, creep; and the measurement of the rate and degree of recovery after removal of stress, ie, creep recovery or recoil. Special topics such as the Weissenberg effect, time–temperature superposition, and electrorheological behavior are also discussed.

show abstract

A Rheometer for Characterizing Polymer Melts and Suspensions in Shear Creep and Recovery Experiments

Cited by 20 publications

References 1 publication

Rheology of extremely shear thickening polymer dispersions^a) (passively viscosity switching fluids)

Rheology of extremely shear thickening polymer dispersions^a) (passively viscosity switching fluids)

Effect of Propylene Glycol Alginate and Xanthan Gum on Stability of O/W Emulsions

Rheology and Rheological Measurements

Contact Info

Product

Resources

About

A Rheometer for Characterizing Polymer Melts and Suspensions in Shear Creep and Recovery Experiments

Cited by 20 publications

References 1 publication

Rheology of extremely shear thickening polymer dispersionsa) (passively viscosity switching fluids)

Rheology of extremely shear thickening polymer dispersionsa) (passively viscosity switching fluids)

Effect of Propylene Glycol Alginate and Xanthan Gum on Stability of O/W Emulsions

Rheology and Rheological Measurements

Contact Info

Product

Resources

About

Rheology of extremely shear thickening polymer dispersions^a) (passively viscosity switching fluids)

Rheology of extremely shear thickening polymer dispersions^a) (passively viscosity switching fluids)