High-strength nanocomposite based on fibrillated chemi-thermomechanical pulp

The incompatibility between cellulose fibers and hydrophobic polymers has presented a major obstacle for the fabrication of composites and nanocomposites. In this study, we applied a one-time grinder treatment to disintegrate chemi-thermomechanical pulp (CTMP) and obtained micro- to nano-meter-sized lamellar or fibrous fragments. The CTMP fragments were composed of cellulose microfibrils with high aspect ratios encased in matrix substances including hydrophobic lignin. Furthermore, we produced compression-molded products from the CTMP fragments by thermally plasticizing lignin without any adhesives or resins. The molded products pressed at 180 °C exhibited a plastic-like gloss on the surface and a high bending strength, 221 MPa, which greatly exceeded that of the conventional plant-based binderless boards. The molded products produced here are a novel form of ideal cellulose nanocomposite, which exploited the inherent compatibility between cellulose microfibrils and matrix substances present in CTMP fragments.