Enhancing the hydrophobicity and strength of paper

An enzymatic method for functionalisation of chitosan (CTS) with a hydrophobic monophenol compound (4-hexyloxyphenol, HP) using laccase was presented, yielding a chitosan derivative (Lac/HP-CTS) as a coating on the Kraft paper sheet.

Improved wet strength

Compared with paper coated by pure chitosan, the hydrophobicity and wet strength of the coated paper via the chitosan derivative were improved significantly at the coating concentration of 0.6 g/100 mL with the coat weight of 1.53 g/m².

Meanwhile, the different enhancement behaviors in the strength (dry or wet) performance were observed, due to the greatly influenced interaction of the hydrogen bonding between the copolymer coating and the cellulose fibers by the grafted HP. Further, the hydrophobicity and strength were observed to be enhanced even at a diluted concentration of 0.1 g/100 mL and a relatively low coating weight of 0.26 g/m² for the chitosan derivative.

Sccording to the publisherx, this study is significant for broadening the coating application of the biomodified chitosan on the packaging papers.

The study has been published in Progress in Organic Coatings, Volume 151, February 2021.