Long-chain cellulose esters from recycling textile waste as highly effective superhydrophobic additive: synthesis and evaluation

The textile industry has a strong interest in superhydrophobicity and water repellence and, in particular, in the development of waterproof, self-cleaning and stain-resistant clothing and other textile products. In this study, to promote hydrophobicity in textiles, novel fluorine-free formulations were developed based on long-chain cellulose esters (LCCEs), synthesized from recycled cellulose in a heterogeneous system. The synthesized LCCEs (with alkyl side chains containing 6 to 18 carbon atoms, C6-C18) were characterized by spectroscopic (nuclear magnetic resonance and Fourier-transform infrared spectroscopy) and thermal (thermogravimetry analysis and differential scanning calorimetry) methods in order to validate their synthesis and intrinsic characteristics. The recycled cellulose was obtained from textile residues, in a circular approach toward textile functionalization. The developed formulations contain regular dry-cleaning solvents. Because of their nontoxicity, and ease of application by conventional drycleaning methods, these LCCEs provide a simple, eco-friendly, sustainable and effective alternative to the compounds currently used for promoting water repellency in textiles. The fabrics treated with the LCCE-based formulations were evaluated for static and dynamic contact angles, surface energy, wettability, water vapor permeability and cytotoxicity. The resistance of the treatment to domestic washing and thermal treatment was also assessed.