Studies of the processing and characterization of corn starch and its composites with banana and sugarcane fibers from Brazil

This paper presents results on the characterization of corn starch by X-ray powder diffraction and thermal analysis, as well as processing and characterization of starch–banana/sugarcane bagasse fiber composites. X-ray diffraction studies revealed that the starch sample belongs to the A-type, common in cereals. Thermal analysis showed good thermal stability for making composites, while fractographic studies of 70 wt.% starch and 30% glycerol matrix revealed cracks between smooth and rough surface and dimples in rough regions, suggesting the sample was ductile. The composites of this matrix with banana and bagasse fibers prepared by compression molding showed more homogeneous composites with crude glycerin and structural changes in both the fiber composites, while their morphology was dictated by the properties of the fibers rather than by those of the matrix. Improvements in tensile properties were observed in these composites over those of the matrix, which are explained based on fractographic observations.