Bio-nanocomposites based on cellulose microfibril

The objective of this study was to develop a new process to manufacture high-strength biocomposites exploiting the unusually high-strength properties of cellulose microfibrils [1, 2]. Most of the studies that have been carried out heretofore were based on film casting techniques of composite fabrication as a way to assure good dispersion of cellulose whiskers or fibrils in the matrix. Some of the studies tried different methods but attained reduced reinforcements due to poor dispersion of cellulose. Here, a novel method to obtain composites by lamination of phenolic resin impregnated sheets of microfibrillated cellulose was proposed. The concept was based on utilizing microfibrillated cellulose (MFC), a cellulose morphology obtained through microfibrillation of kraft pulp fiber by mechanical processesses of refining and high-pressure homogenization [3, 4]. The treatment confers drastically large surface area to the material, characterized by a nano-scalar, web-like networked fibrils and microfibrils, which have the potential to increase interactive forces between reinforcing elements and matrix in a composite. When the mechanical properties of MFC-based composites were compared with those of non-fibrillated kraft pulp-based composites, there were no significant differences in Young's modulus, around 18-19GPa. However, the ultimate strength of MFC composites achieved 370MPa, a value 1.4 times higher than that of pulp composites [5]. The higher strength was an effect of the larger yield strain resultin