Biobased Hydrophobic Solutions for Natural Textiles—Moving Beyond PFAS

In order to achieve hydrophobic properties in textiles, per- and poly-fluoroalkyl substances (PFAS) are often used. These chemicals represent a class of synthetic compounds that have found wide application in numerous industries because of their advantageous properties, such as hydrophobicity, lipophobicity, chemical inertness, remarkable lubricity, non-stickiness, exceptional fire resistance, resistance to high temperatures, and high resistance to various weathering conditions. However, recent scientific research has demonstrated that these compounds possess persistent, accumulative, and highly mobile properties that make them an environmental hazard. Since the toxicity of PFAS is now recognized, ongoing research has been initiated to explore new substitutes. This comprehensive review focuses on the exploration of natural-based hydrophobic coatings for natural textiles, which include materials such as natural waxes, fatty acids, naturally occurring polymeric compounds (including proteins, carbohydrates, complex aromatic polymers, and polymers like natural rubber), and other naturally occurring substances. The role of each compound in the hydrophobic coating is also highlighted. This review aims to evaluate the potential of natural compounds as viable replacements for PFAS, focusing on their efficiency and durability.