Capillary breakup extensional rheometry of sodium carboxymethylcellulose solutions in water and propylene glycol/water mixtures

Abstract

This article presents the results of capillary break-up extensional rheometer experiments conducted for semidilute solutions of carboxymethylcellulose sodium salt (Na-CMC) with degrees of substitution (DS) ranging from 0.62 to 1.04 in distilled water and propylene glycol (PG)/water mixtures. The partial aggregation of Na-CMC chains with DS < 1 observed in aqueous solutions triggers an increase in apparent extensional viscosity and extension of break-up time. The rheological properties of Na-CMC solutions in propylene glycol/water mixture are determined by the solubility of the polymer and the physical crosslinking of chains. The disappearance of the elasto-capillary regime during the filament thinning of Na-CMC solutions with DS < 1 in propylene glycol/water mixture was linked to the physical crosslinking of polymer chains. The shape of the extensional viscosity curve for Na-CMC solutions with DS = 1.04 in PG/water mixture was characteristic for semidilute polymer solutions with a low number of entanglements.

Oleo‐Dispersions of Electrospun Cellulose Acetate Butyrate Nanostructures: Toward Renewable Semisolid Lubricants

“…Parameter B is directly related to the extensional relaxation time as follows: B = 1/3λ E . [ 49 ] Table 1 collects the values of relaxation time, λ E , as a function of the CAb concentration. An important increase in the relaxation time for CAb concentrations higher than 10 wt.% can be observed.…”

Pinching dynamics, extensional rheology, and stringiness of saliva substitutes

“…Therefore, the rheology displays sensitivity to salt, pH, temperature, and solvent composition. 69,72–80…”

“…Therefore, the rheology displays sensitivity to salt, pH, temperature, and solvent composition. 69,[72][73][74][75][76][77][78][79][80] Pinching dynamics of artificial saliva formulations manufactured for industry use Pinching dynamics and extensional rheology response of the saliva substitutes were characterized using a dripping-ontosubstrate (DoS) rheometry set-up schematically shown in Fig. 3a.…”

Effect of isopropanol cosolvent on the rheology and spinnability of aqueous polyacrylic acid solutions

“…Despite their importance, previous studies examining the effect of water–alcohol composition on fiber morphology of PAA solutions have only considered shear rheology in correlating to the fiber morphology, and are rarely reported even in studies on using aqueous or other media. Studies focused on extensional rheology are also fewer on polyelectrolyte solutions in water–alcohol mixtures 44–47 compared to in water/polar media 48–51 …”

“…Studies focused on extensional rheology are also fewer on polyelectrolyte solutions in water-alcohol mixtures [44][45][46][47] compared to in water/polar media. [48][49][50][51] In this study, we examine the influence of alcohol cosolvent on the shear and extensional rheological properties, and the onset of fibers-both beaded and uniform-of PAA solutions. And we analyze the relationship between the onset of fiber formation and rheological properties to understand the role of viscoelasticity on fiber formation.…”