The viscosity of an aqueous WALOCEL™ CRT solution is defined by the frictional resistance of a fluid to shear forces or to compressive stress, hence to flow.
To cater to the requirements of the many different applications, Dow Wolff Cellulosics offers a broad selection of WALOCEL™ CRT A - Cellulose Gum, clear+stable™, WALOCEL™ C and WALOCEL™ CRT grades. The viscosity range from 10 mPa·s to 100,000 mPa·s as a 2% solution.
The viscosity of CMC solutions is determined using, for instance, Brookfield viscometers, rotary viscometers or Höppler viscometers. The viscosity is stated in Pas or mPa·s. Depending on the method applied, the viscosity stated may vary considerably.
Measuring the viscosity of a 2% aqueous CMC solution, e.g. using WALOCEL CRT 20,000 GA, will result in the following readings:
- 25,000 mPa·s measured with a rotary viscometer at a shear rate of 2.55 1/s
- 42,000 mPa·s measured with a Brookfield LVT viscometer
- 130,000 mPa·s measured with a Höppler viscometer
This shows very clearly that the viscosity of an aqueous CMC solution is not an absolute value, but depends very much on the measuring parameters. In order to ensure that the stated viscosity are comparable, we always specify WALOCEL CRT A - Cellulose Gum and WALOCEL CRT products using Brookfield viscometers at 25°C. WALOCEL CRT...PV products are specified using a rotary viscometer at 20°C.
The properties of WALOCEL CRT are essentially based on the specific behaviour of WALOCEL CRT solutions in water. The WALOCEL CRT solutions are pseudoplastic and - at higher concentration levels - thixotropic.
For some applications, not only the viscous but also the elastic properties are of importance. Do you have any questions or requests? Would you like some more detailed information? If you contact us, we would like to assist you further.
