Enhancement of hydrophobicity of kraft pulp via a laccase-lauryl gallate treatment

Abstract

To confer hydrophobic properties to Kraft pulp, an environmentally friendly process using laccase and lauryl gallate (LG) was developed. This treatment resulted in paper with very high water-barrier properties. The loss of hydrophobicity after acetone Soxhlet extraction highlighted the key role of adsorption phenomena on the introduction of pulp properties. GC-FID analysis of the extraction supernatants revealed large quantities of LG and dodecanol, and HPSEC-UV analysis revealed the presence of phenolic oligomers. Additional light microscopy examinations detected filamentous elements in the LG+Lac pulp corresponding to oligomers formed during the enzymatic reaction. Because this treatment is designed for packaging applications, pulp stratification enabled to obtain paper with acceptable mechanical properties. The influence of initial Kraft pulp quality (at different refining degrees and lignin contents) was also investigated