Extensional flow of carboxymethylcellulose sodium salt measured on the opposed-nozzle device

ABSTRACT

The study presents results of the shear viscosity and apparent extensional viscosity measurements performed for semidilute solutions of carboxymethylcellulose sodium salt with two different average molecular weights and three different degrees of substitution, in distilled water and with the addition of NaCl. An increase in the weight average molecular weight of Na-CMC triggers a rapid increase in the apparent extensional viscosity and the Trouton ratio. Another finding was that the values of the apparent extensional viscosity and the Trouton ratio rose with a decrease in the degree of substitution, which can be attributed to the presence of interchain hydrogen bonds. The addition of NaCl to the Na-CMC solutions induces a reduction in the apparent extensional viscosity and the Trouton ratio, which can be linked to a change in the configuration of the polyelectrolyte chain.

Keywords:

• Extensional viscosity
• polyelectrolyte
• sodium carboxymethylcellulose
• Trouton ratio

Funding

The financial support of Ministry of Science and High Education (Poland) is gratefully acknowledged (Grant 03/32/DSPB/0702).

Additional information

Funding

The financial support of Ministry of Science and High Education (Poland) is gratefully acknowledged (Grant 03/32/DSPB/0702).