Cellulose Nano Fibers (CNFs) is expected to be utilized in various fields because of its attractive properties such as high strength, high rigidity, and low coefficient of linear expansion. CNFs have attracted significant attention as materials that can enhance the mechanical properties of polymers. CNFs can easily form hydrogen bonds between CNFs because of the many hydroxyl groups on the surface of a CNF. Therefore, in many cases, CNF agglomerates with diameters greater than 100 μm remain in a composite when compounded with hydrophobic polymers. Recently, we can success in preparing the dry powders of CNFs by coating of hydrophobizing agent and special drying (trial products by Sugino Machine ; 20 nm of fiber diameter, 1 and 10 μm of fiber length) . The CNFs are easily dispersed in a polypropylene (PP) matrix by melt-compounding with using a twin-screw extruder. No agglomerates of CNFs with diameters greater than 1 μm can be found in the composite by optical microscope observations and TEM observations of electron staining ultrathin section.
In this article, we introduce a dispersion mechanism of CNFs in polymers, development of CNF dray powders which are easily dispersed in polymers and the outline of our CNF nanocomposite studies in the joint researches with companies by support programs of MEXT, NEDO and SME Agency.