Development of fluorine-free waterborne textile finishing agents for anti-stain and solvent-water separation based on low surface energy (co)polymers

Abstract Fabric functionalization to obtain omniphobic textiles is an increasing trend due to science and technology push in our current society. Fluorochemicals dominate the water and oil-repellent textile finishing market because of their excellent performance. However, fluorinated chemicals release harmful substances giving rise to serious damage to ecosystems worldwide. In this paper, a series of fluorine-free, low surface energy and partially bio-based (co)polymethacrylates based on 3-[Tris(trimethylsilyloxy)silyl]propyl methacrylate (M3T) and stearyl methacrylate (SMA) have been successfully synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Energy-Dispersive X-ray Spectroscopy (EDS). Moreover, the particle size, particle size distribution and stability of developed emulsions have been assessed by laser diffraction spectrometry (LDS) and Z-potential measurements. The fluorine-free M3T/SMA (co)polymethacrylates have been applied on cotton fabrics by padding at several product dosages and coated textiles have been characterized by scanning electron microscopy (SEM), EDS element mapping, X ray fluorescence (XRF) and water and olive oil static contact angle measurements, WCA and OCA, respectively. Finally, performance of the fabrics treated with the new M3T/SMA (co)polymethacrylates has been evaluated and compared with textiles finished with conventional fluorinated chemicals. All the synthetized (co)polymethacrylates provide the coated substrates with high static water contact angles as well as excellent solvent-water separation efficiencies. However, only the textiles coated with the (co)polymethacrylates with higher M3T contents showed good repellence to olive oil, being able to keep the drop of oil on the surface for longer times. This time-dependent olive oil’s wettability observed for the copolymers with low contents on M3T units may be ascribed to: i) the evolution with time of the surface free energy of the coatings due to a reorientation over time of stearyl side chains of SMA during contact with the olive oil; and ii) the reduced barrier properties of the coatings with lower content of the bulky tris(trimethylsilyloxy)silyl side chains.