Effect of initial fiber length on the rheological properties of sisal fiber/polylactic acid composites

The rheological properties of sisal fiber (SF)/polylactic acid (PLA) composites of different SF content and initial fiber length were evaluated using a torque rheometer. Since the SF configuration directly affected the rheological properties of the composites, the length and width of SFs in the final composites were measured. The effect of fiber content, angular velocity, and initial fiber length on the fiber aspect ratio (length to width ratio) and composite rheological properties were analyzed. Initial fiber length significantly affects the rheological properties of SF/PLA composites at low SF content, while fiber content predominantly affects rheological properties at high SF content, and rheological parameters are similar for the composites of different initial fiber length. The average shear stress and mixing temperature are affected by feeding speed for composites of very high SF content. POLYM. COMPOS., © 2011 Society of Plastics Engineers.