Oil- and water-resistant paper substrate using blends of chitosan-graft-polydimethylsiloxane and poly(vinyl alcohol)

Reported herein is an economical, plastic- and fluorine-free coating approach for oil and water repellent paper substrates using blends of poly(vinyl alcohol) and chitosan-graft-polydimethylsiloxane copolymer. The obtained coated paper showed good water-resistance, as evidenced by its low Cobb60 values of similar to 20 +/- 2.1 g/m(2) and high water contact angles of 119 +/- 6.3 degrees. The kit rating of the coated paper was 7.6/12, indicating decent grease-resistant properties as compared to the kit value of 0/12 for the uncoated paper. The coated paper is also repulpable as demonstrated by the complete washing off the coating from the coated paper. Giving the cost-effective nature of the coating materials and good water and oil-resistant properties of the coated paper, the approach developed here is commercially viable, and will offer a multitude of environmental benefits such as the elimination of microplastic- and PFAS problems associated with existing paper coatings.