Hydrothermal treatment of sisal fiber for composite preparation

The influence of hydrothermal carbonization of sisal fibers on the mechanical properties of composites based on recycled polypropylene matrices was investigated in this paper. The fibers were characterized by X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The composites, with short fibers randomly distributed, processed by extrusion and injection processes, were characterized using quasi-static tensile and impact mechanical tests and scanning electron microscopy. The hydrothermal carbonized sisal fibers, proved by Fourier-transform infrared spectroscopy analysis, besides increasing the material's crystallinity, caused a larger adherence on the interface fiber/polymer matrix as verified in the scanning electron micrographs. The addition of 10% and 20% of 2？h hydrothermal carbonized sisal fibers treatment produced a composite with, respectively, an increase of 17.9% and 32.2%, on the modulus of elasticity, of 9.25% and 52.3% on the resistance to impact and of 19.06% and 29.85% on yield strength, in comparison to the recycled polypropylene. The hydrothermal carbonization technique changed the concept of recycling the polypropylene allowing new applications to the produced materials due to its mechanical properties