All-Cellulose Nanocomposite Made from Nanofibrillated Cellulose

Commercial microfibrillated cellulose (MFC) was ground and turned into nanofibrillated cellulose (NFC), then all-cellulose nanocomposites (ACNC) were prepared by partially dissolving method. The nanocomposites, with different ratios of undissolved core part of NFC in a matrix of partially dissolved skin part of NFC, were produced using DMAc/LiCl as solvent system. Five dissolution times of 5, 10, 20, 30 and 60 minutes were used as variables and the results were compared with the properties of neat MFC and NFC sheets. The structure and properties of MFC, NFC and nanocomposites were characterized using atomic force microscopy, field emission scanning electron microscopy, X-ray diffraction and tensile tests. The mechanical properties of NFC are significantly larger than those of MFC. As dissolution time increased, the apparent crystallinity of ACNC decreased and more amount of matrix covered the nanofibre surfaces. The ACNC showed best tensile strength (156 MPa) and Young's modulus (13.2 GPa) at 10 minutes dissolution time. The advantage of ACNC is that they are fully bio-based, easily recyclable, fully biodegradable and strong materials.