Introduction
Textiles have relied, for a long time, on coatings containing per- and polyfluoroalkyl substances (PFAS), to achieve superior hydrophobic, oleophobic and stain-resistant properties. These coatings excel not only at repelling liquids, but also stand out for their durability, including resistance to heat, chemicals, and physical stress. However, the exact chemical structure, which provides durable properties, is also responsible for their persistence in the environment and accumulation in living organisms, raising a significant concern for environmental and human health. Our research presents a hydrophobic coating based on natural biopolymers sourced from renewable materials, which not only imparts hydrophobicity on textiles but also offers a safer alternative to PFAS, which reduces environmental and health risks.
Methods
A plain weaved 100% cotton (CO) and polyester (PES) fabrics were rod-coated with multiple variations of a coating, containing a suspension of biopolymer-based microcapsules (MCs). The coated samples were analyzed to determine the presence and the distribution of MCs (scanning electron microscopy—SEM), hydrophobic properties before and after washing (water contact angle—WCA), physical properties (thickness, mass per unit area), mechanical properties (tensile strength), and change in color.
Results
The results showed that hydrophobicity of the coated samples was achieved with minimal impact on the original properties of the CO and PES fabrics. The SEM analysis confirmed the presence of MC on the fibre surface. The WCA has increased from below 10 ° for untreated samples to above 120 ° for coated samples. Samples retained hydrophobic properties after washing, with some samples exceeding WCA of 120 °. No significant changes in colorimetric parameters were observed after the coating deposition.
Conclusions
A hydrophobic coating based on natural biopolymer microcapsules was successfully applied to CO and PES fabrics, providing durable hydrophobicity without altering the fabric color. This fluorine-free formulation offers a safer and environmentally friendly alternative to PFAS-based textile coatings.
