Abstract
Functional textiles have been one of the most studied topics in recent decades. Due to toxicity concerns, thetreatment of fabrics for non-wettable properties with fluorinated molecules is nowadays limited to short fluoroalkylchains. In this work, several fluorinated (meth)acrylic monomers such as 1,1,1,3,3,3-hexafluoroisopropylmethacrylate, 2-(perfluorobutyl)ethyl methacrylate, 1H,1H,2H,2H-perfluorooctyl methacrylate, 1H,1H,2H,2Hperfluorooctylacrylate and 1H,1H,2H,2H-perfluorodecyl methacrylate (denoted as M2, M4, M6, AC6 and M8,respectively) were grafted onto flax fabrics to improve their hydrophobic and oleophobic properties by radiograftingusing a pre-irradiation procedure. The effects of the length of the fluoroalkyl group of the monomer, theirradiation dose and the reaction time on the grafting rate were studied. The functionalization of flax fabrics bythese five monomers was confirmed by FTIR spectroscopy analysis. The morphology of the fibers before and aftertreatment was studied by scanning electron microscopy (SEM). The location of fluorine element in the flaxelementary fibers was assessed by SEM-EDX. The hydro- and oleophobic properties were determined by contactangle measurement using water and diiodomethane as solvents, respectively. The sliding angle was alsomeasured to assess the water repellency of hydrophobic fabrics. Significant fluorine contents were obtained forflax fibers irradiated and treated with 10 wt% solutions of monomer. Hydro- and oleophobic fabrics were obtainedfor flax irradiated even at a low dose of 5 kGy and treated with M4, with water and diiodomethane contactangles (CAs) of about 139◦ and 120◦, respectively. Superhydrophobic fabrics (CA = 150◦) were also achieved forsamples irradiated at 20, 50 and 100 kGy and treated with 10 wt% of M8. For this monomer, SEM analysisshowed the formation of spherical microparticles of fluoropolymer covering the surface of elementary fibers. Theformation of these particles is assumed to result from a dispersion polymerization mechanism. This is due to thefewer affinity of M8 with methanol and to the incompatibility of the formed polymer chains with this solventused for the grafting reaction.