The growing environmental and health concerns over fluorochemicals coated paper and single use plastics/plastic coated paper, have led to a great interest in biodegradable and repulpable alternatives to obtain water- and oil-repellent paper substrates. The work reported herein aims at addressing these concerns by developing a fluorine-free, thermoplastic-free, and cost-effective water- and grease-resistant paper coating, using biodegradable polymers like polyvinyl-alcohol (PVOH) and starch blended with chitosan-graft-polydimethylsiloxane (chitosan-g-PDMS) copolymer. The hydrophobic and oleophobic performance of the coated paper with PVOH and chitosan-g-PDMS blend yielded good water-resistance (Cobb60 value: 20±2.4 g/m2) and a moderate oil resistance (7/12 kit rating). Superior water and grease resistance were achieved with starch and chitosan-g-PDMS blend as the coating material where the Cobb60 values and kit ratings were 13±0.9 g/m2 and 12/12, respectively. The repulpability of the coated papers is also demonstrated in this study by washing the coating materials from the paper and repulping the pulp. This novel, inexpensive, water- and grease-resistant, environmentally friendly coating offers promising candidacy for commercial use in a myriad of applications in the packaging sector.
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