Hydrophobic modification of nanocellulose and all-cellulose composite films using deep eutectic solvent as a reaction medium

Abstract In this work, deep eutectic solvent (DES) based on imidazole and triethylmethylammonium chloride was used as a reaction medium for the esterification of cellulose nanofiber (CNF) all-cellulose composite (ACC) films with n-octylsuccinic anhydride (OSA) to obtain high strength sustainable increased hydrophobicity. Diffuse reflectance infrared Fourier transform spectroscopy X-ray photoelectron were prove success modification. The mechanical modified analyzed in dry, humid, wet conditions, hydrophobicity indicated terms contact angle measurements. addition, water absorption transparency characterized. modification proven be simple fast, mild conditions 80 °C temperature 1 h time used. DES/OSA- CNF film exhibited better properties compared reference film, DES/OSA-modified ACC displayed notable higher state that (31 MPa tensile 6.1% strain at break vs. 18 2.2%, respectively). These improvements partly attributed angles (ACC-DES/OSA 60° CNF-DES/OSA 51°) (37°). Graphic abstract