Effect of chemically modified nanofibrillated cellulose addition on the properties of fiber-based materials

• Modified nanofibrillated cellulose (NFC) added in wet-end paper process for the first time.
• Mechanical reinforcement and decreased air permeability with both modified and unmodified NFC.
• Strong diminution of water absorption (divided by more than 6) with modified NFC.
• Multi-level properties: hydrophobicity, mechanical reinforcement and air permeability.

In the present work, nanofibrillated cellulose (NFC) has been chemically modified by nanoemulsion process. Surface chemical modification has been proved by Fourier transform infra-red spectroscopy (FTIR). Modified NFCs have been added in wet-end paper process for the first time and the properties of the ensuing fibre-based materials have been measured. Mechanical reinforcement is observed whichever the NFC (treated or not). With 16 wt% of modified NFC, Young's modulus and breaking length display an increase of 72% and 51% respectively. Air permeability strongly decreases with modified NFC. The main advantage is the strong diminution of water absorption (divided by more than 6). The synergy of such properties is very difficult to achieve and this new strategy opens the field of several application like barrier material or filtration.