Water‐soluble polymers. LXXXII. Shear degradation effects on drag reduction behavior of dilute polymer solutions

Abstract

Drag reduction measurements were conducted on extensively characterized poly(ethylene oxide) and poly(acrylamide) utilizing a fully automated rotating disk rheometer equipped with an optical tachometer, torque transducer, and software allowing real-time data acquisition. The instrument sensitivity allowed the study of concentrations as low as 0.1 ppm. In addition, previously immeasurable concentrationand time-dependent shear degradation effects were readily observed. A power law equation was shown to adequately correlate the percentage of drag reduction and the volume fraction for each polymer. Furthermore, an empirical shift factor was utilized to superimpose data from all the systems that were studied. By conducting measurements in the proper concentration and time domains, it was possible to extract the minimal concentration for the maximum drag reduction efficiency in the absence of shear degradation. The resulting values were significantly higher than those previously reported by our laboratories for poly(ethylene oxide) and poly(acrylamide).

Polymer–surfactant complex formation and its effect on turbulent wall shear stress

“…The percentage of maximum drag reduction increases with increasing PEO molecular weight, i.e., %DR is 24, 68, 83, and 85% for PEO M w equal to 3.04 × 10 5 , 6.06 × 10 5 , 8.03 × 10 5 , and 17.9 × 10 5 g/mol, respectively. All of these observations are generally consistent with previous observations of PEO solutions [37], and also consistent with either the viscometric [11][12][13][14] or elastic [15,16] theories of drag reduction. Beyond the c * PEO [η], %DR decreases with increasing PEO concentration.…”

Embryonic development of folate binding protein‐1 (Folbp1) knockout mice: Effects of the chemical form, dose, and timing of maternal folate supplementation

“…Amphiphilic polyelectrolytes are an important class of polymers that exhibit self‐assembly in aqueous media 1–13. These macromolecules possess both charged and hydrophobic units along or pendant to the polymer backbone.…”

“…Our group has had a long‐time interest in designing stimuli‐responsive polymers for personal care, water remediation, pharmaceutical delivery, and enhanced petroleum production 2, 7, 9–11, 13, 14, 18, 21, 22. In the last area, we have been especially involved in structuring (co)polymers with reversible modes of intra‐ and intermolecular association in response to changes in pH and/or ionic strength.…”

A study of the products and mechanism of the thermal oxidative degradation of poly(ethylene oxide) using 1H and 13C 1‐D and 2‐D NMR

“…The degradation characteristics of polymers are of considerable practical importance. The thermal,1–15 photolytic,15–21 electrolytic,22 mechanical (ultrasonic or shear)23–25 and radiation26, 27 induced degradation properties of poly(ethylene oxide) (PEO) itself and composite systems containing PEO have been studied previously mainly using techniques such as analysis of evolved products, mass loss, molar mass measurements, thermogravimetric analysis (TGA), differential scanning calorimetry and FTIR. It is of interest to investigate the structure of the degradation products spectroscopically for two reasons, first because of the light those structures shed on the mechanism of degradation, and second because of the value of those spectra as a reference for the purity of materials after storage or use.…”