Modification of cellulosic fibres with functionalised silanes: development of surface properties

The surface modification of cellulosic fibres was carried out using organofunctional silane coupling agents in an ethanol/water medium. A heat treatment (curing) was applied after reaching the equilibrium adsorption of the prehydrolysed silanes onto the cellulosic substrate. The modified fibres were then characterised by diffuse reflectance infrared spectroscopy and contact angle measurements. The presence of Si–O–Cellulose and Si–O–Si bonds on the cellulose surface confirmed that the silane coupling agent was efficiently held on the fibres surface through both condensation with cellulose hydroxyl groups and self-condensation between silanol groups. The change of the surface properties after the modification was ascertained by contact angle measurements and inverse gas chromatographic analysis. It was shown that the silane functional groups appended to the fibre surface could participate in the chain growth of appropriate monomers to give a covalent continuity between the fibres and the ensuing polymer matrix.