Modification of Cotton Fibre with Functionalized Silane Coupling Agents Vinyltriethoxysilane and Aminopropyltriethoxysilane

Cotton fibre was modified by condensation polymerization with functionalized silane coupling agents like vinyltriethoxysilane (VTES) and aminopropyltriethoxysilane (APTES) in an ethanol/water medium. The modification of cotton fibre enhanced the tensile properties, softness properties, water repellence and wrinkle recovery, due to higher flexibility of the Si-O bond between the silane coupling agents and the cotton fibre. The ability of the modified cotton fibre to swell decreased in an aqueous solution, which affects the overall chemical suitability of the fibre. The optimized condition in which to modify cotton fibre was a monomer concentration of: 500% for VTES and 600% for APTES (depending on the weight of the fibre); pH 3.5 for VTES and 5 for APTES: ethanol-water ratio 40:60 for VTES and 80:20 for APTES; reaction time of 90 minutes both for VTES and APTES at room temperature (30°C), in the fibre-liquor ratio of 1:50. Swelling of the modified cotton fibre decreased in polar solvents and increased in nonpolar solvents. Fourier transform Infrared spectroscopy was used to identify the incorporation of siliconcontaining molecules. Energy Disperse X-ray analysis determined the quantities of atomic silicon which directly reflects its valence bond with organic moieties. Scanning electron microscopy and thermogravimetric analysis were used to investigate the surface morphology and thermal behavior of the modified fibre, respectively. Examination of the dyeability of washed and modified cotton fibres, dyed with Reactive Brown-10 and Reactive Orange-14, showed that the absorption of dye by modified fibre was comparatively higher than that of raw cotton fibre.