Rheological study of polymer‐surfactant interactions in cellulose derivatives and gelatin aqueous solution

Abstract

The rheological properties of water soluble cellulose derivatives (hydroxypropylcellulose, modified hydroxyethylcellulose) and gelatin aqueous solutions in a system with ionic surfactant were studied. The viscosity maximum was found in the region of critical micellar concentration (CMC) of the surfactant as a result of micelle formation. An increase of the CMC value with increasing molecular weight was observed and a decrease of this value for the hydrophobically modified polymer solution was found compared to the CMC value of the surfactant aqueous solution. A slight viscosity maximum was also found in gelatin systems with cationic and anionic surfactant. The viscosity increase (cross bonding) of gelatin aqueous solutions is more affected by a cationic surfactant than by an anionic one. pH measurements on gelatin systems indicate that the minimal viscosity is reached in the region of the isoelectric point.

Influence of additives on the fabric stiffness and colour depth of viscose printed with a guar gum thickener and a reactive dye

“…Commercial [13] Mathis drying machine for 5 min at a temperature of 40 °C, steamed in a Werner Mathis DHE 15973 machine for 10 min using saturated steam at a temperature of 102 °C and washed four times using demineralised water at a temperature of 95 °C. The samples were then conditioned at 20 °C and 65% humidity for 24 h.…”

“…The type of surfactant used and its concentration also significantly influences the extent of dye penetration, as shown in Table 3. The dye penetration is lowest when the C 18 EO 10 surfactant was used, owing to the strong hydrophilic interactions between the surfactant and the guar gum [13,14].…”

“…Table 4 shows the influence of the viscosity (η) and viscoelasticity (tan δ) of printing pastes made with (5% w/w) and without C 18 EO 10 , with reactive dye (5% w/w) and with different thickeners on the paste add-on and the dye penetration. The dye penetration is lower when the C 18 EO 10 surfactant is used (see Table 3), owing to the strong hydrophilic interactions between the surfactant and the guar gum [13,14], resulting in a highly viscous and more elastic (lower tan δ, [15,18]) printing paste. The results in Table 4 show that the increasing DS of the thickeners causes a stronger surface printing and a poor extent of dye penetration.…”