Recyclable, UV-shielding, and biodegradable chitosan-based cardanol glycidyl ether as excellent water and oil resistance as well as gas barrier coating for paper

Developing a feasible and low-cost approach to fabricate recyclable, UV-shielding, biodegradable as well as water- and oil-resistant coating for paper substance is still a challenge. Herein, novel full-biobased chitosanderived cardanol glycidyl ether (CS-xCGE, x = 1/8, 1/4, 1/2, and 1) coatings with different contents of cardanol glycidyl ether (CGE) were developed for paper substance via the ethoxylation of cardanol and sequent addition with chitosan in a one-pot process. Benefiting from the hydrophobicity and ultraviolet resistance of CGE, the resultant CS-CGE (x = 1) coated paper exhibited not only remarkable oil resistance (kit rating value of 11/12), but also water resistance (Cobb 60 value of 5.78 g/m2), UV shielding and excellent recyclability. Compared with the uncoated paper, the mechanical properties of CS-CGE coated paper including tensile strength, folding strength, and resistance of water vapor permeability were improved 25 %, 63 %, and 73.4 %, respectively, which could be ascribed to the flexible long-alkyl chain in the structure of CS-CGE and the continuous and homogeneous CS-CGE derived film covered in paper substance. Most importantly, CS-CGE film is biodegradable when it is only buried in soil. This study affords a feasible and sustainable strategy for large-scale fabrication of fullbiobased, recyclable, UV-shielding, water and oil resistant, as well as biodegradable coating for green paperderived packaging.

Automated summary

Developing a feasible and low-cost approach to fabricate recyclable, UV-shielding, biodegradable, water- and oil-resistant coating for paper is a challenge. In this study, novel full-biobased chitosan-derived cardanol glycidyl ether (CS-xCGE) coatings with different contents of cardanol glycidyl ether (CGE) were developed for paper substance. The resulting CS-CGE coated paper showed remarkable oil resistance, water resistance, UV shielding, and improved mechanical properties compared to uncoated paper. The CS-CGE film was also found to be biodegradable. This study provides a feasible and sustainable strategy for green packaging made from biodegradable, recyclable, UV-shielding, water- and oil-resistant coating.