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

Abstract 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 ~20 ± 2.1 g/m 2 and high water contact angles of 119 ± 6.3 °. 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.