Surface modification of microfibrillated cellulose for epoxy composite applications

Microfibrillated cellulose (MFC) possessing a 'web-like' morphology was successfully modified with three different coupling agents: 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, and a titanate coupling agent (Lica 38). The surface modification was confirmed using infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), environmental scanning electron microscopy (ESEM), and contact angle measurements. These modifications changed the surface character of MFC from hydrophilic to hydrophobic. The untreated and treated MFC were successfully incorporated into an epoxy resin system using acetone as the solvent. Better and stronger adhesion between the microfibrils and the epoxy polymer matrix was observed for the treated fibers, which resulted in better mechanical properties of the composite materials.