Rheology

Our labs provide several rotational and capillary rheometers (Fungilab) which can be used for the analysis of the viscoelastic properties of solutions and dispersions over a wide temperature range. The knowledge of the rheological properties is a crucial factor in many processes in the cellulose manufacturing industry. The molecular mass (M) and the degree of polymerization (DP) can be determined viscosimetrically after dissolving the cellulose samples in solvent EWNN (FeTNa sodium salt of ferric tartaric acid) according to standard DIN 54 270. The viscosity measurements were performed in a modified Ubbelohde viscometer (capillary length 78 mm, capillary bore width 0.75 mm, volume of the bulb between the marks 7 cm3). The intrinsic viscosity [] was calculated from the efflux time of cellulose solution (t), the blank EWNN solution (t0), and from the concentration of cellulose in solution (c) according to the Schulz-Blaschke equation. Suitable samples: solutions.