Title
Solution properties of some modified lignins
Authors
MANUELA-TATIANA NISTOR OANA CHIRILA GEORGETA CAZACU MARIAN I. TOTOLIN and CORNELIA VASILE

Published Volume 48 Issue 9-10 November-December
Keywords lignin, carboxylic acids, butyrolactone, particle size analysis, zeta potential

Abstract
In this paper, the behavior of modified/unmodified organosolv lignin (Alcell) solutions has been studied. Organosolv lignin was modified with different carboxylic acids, such as oleic, butyric, lactic acids and butyrolactone under cold plasma discharge. The modified lignins were characterized by particle size analysis and zeta potential measurements in water and alkaline solutions. It has been established that modification with different carboxylic acids, such as oleic, butyric, lactic acids, and butyrolactone under cold plasma discharge leads to structural and morphology changes of the solution properties for each kind of modified lignin. By cold plasma functionalization, solubility is changed, particle size and conductivity of aqueous solutions decrease, homogeneity decreases and zeta potential takes values close to the stability limit for dispersions. All these characteristics vary with the pH of solutions. In alkaline medium, the sizes of the lignin particles had a bimodal distribution, comparatively with the case of weak alkaline and acidic media. In acidic medium, the lignin associates had the greatest hydrodynamic values.