Study on the compounding of sodium N-lauroyl glutamate and cationic cellulose

Abstract

In this work, sodium N-lauroyl glutamate (SLG) was mixed with cationic cellulose JR30 M. The rapidly occurring change in surface tension and the mass action law of the mixed (compound) system were investigated using dynamic and equilibrium surface tension methods. The behaviour of the system during phase separation was investigated by turbidimetry. The results showed that in the presence of JR30 M, the surface tension of SLG was reduced to a lower level in the given time interval due to the strong interaction compared to that of a solution with the same concentration of SLG but without JR30 M. The largest decrease was obtained with a JR30 M concentration of 0.2 g L⁻¹, which reduced the equilibrium surface tension of SLG from 38.4 mN m⁻¹ to 31.7 mN m⁻¹. The rate of decrease in surface tension increased from 37.61 mN m⁻¹ s⁻¹ to 74.7 mN m⁻¹ s⁻¹. An association complex formed between SLG and JR30 M, and the equilibrium surface tension curve showed a double platform. As the concentration of JR30 M increased, the first platform broadened and the CMC value increased. The phase separation behaviour of the compound system disappeared with the increase of SLG concentration, and the area became narrower with the decrease of JR30 M concentration.