Influence of Different Treated Cellulose Fibers on the Mechanical and Thermal Properties of Poly(lactic acid)

Cellulose microfibrils (CMFs) were prepared from sisal fiber (SF) and characterized using Fourier transform infrared and X-ray diffraction analysis. Further, modification of CMF has been carried out using alkali and silane. Thereafter, modified as well as unmodified CMF reinforced poly(lactic acid) (PLA) biocomposites were fabricated using melt blending technique followed by injection molding. PLA has also been grafted with maleic anhydride and fabricated with unmodified CMF. Differential scanning calorimetry measurements confirmed that the addition of CMF accelerates the crystallization process of the PLA matrix. The NaOH treated SF, i.e. NCMF, reinforced biocomposites exhibited optimum mechanical strength which increased by 21.4% over that of CMF reinforced PLA biocomposites. A silane treated PLA biocomposite showed a maximum impact strength which was 24% higher than that of virgin PLA. The thermal stability of PLA/CMF biocomposites has been evaluated using thermogravimetric analysis. The scanning electron micrographs also confirmed the uniform dispersion of CMF within the PLA matrix.