PROPERTIES OF NANOFIBRILLATED CELLULOSE PREPARED BY MECHANICAL MEANS

Nanofibrillated celluloses (NFCs) were prepared from four different sources of cellulose, namely, hardwood, softwood, cotton linter and cattail, by using a Super Masscolloider mechanical fibrillation device. The NFCs had the average diameters in the range of 30 to 70 nm and the average lengths of several micrometers. Their aspect ratio was found to be of 70-150. Cattail fiber turned out to be a valuable NFC source due to the least energy needed for NFC preparation. Nevertheless, cattail NFC showed high tensile and excellent thermal properties, similarly to wood cellulose NFCs. It was also found that the alpha-cellulose contents, the degrees of polymerization and the crystallinity indices of the NFCs all decreased greatly because of the grinding treatment. The NFCs were used as reinforcing materials in preparing unrefined hardwood (Hw) handsheets (with various Hw:NFC ratios) and a great improvement in bonding properties was observed. The NFC films exhibited Young's moduli of 8-10 GPa, while cotton linter NFC presented the least film strength among them because of lack of hemicelluloses.