Effect of fiber treatments on mechanical behavior of short fique fiber-reinforced polyacetal composites

Different types of natural fiber composites with thermoplastic matrices have been extensively investigated, especially with polyolefins. However, the ability of these fibers as reinforcement of technical matrices has been less studied. This study evaluates the possibilities of using fique fibers (hard fibers) obtained from leaves to reinforce technical matrices such as polyoxymethylene (POM). The mechanical behavior of fique fiber-POM matrix composites has been analyzed as a function of the fiber length, the fiber content, and the surface modification of the fiber. The treatments used correspond to alkalization, and using of formaldehyde, glycidyl methacrylate, and an isocyanate compound. The mechanical properties of these treated fiber composites are higher than those of the untreated ones, due to the enhancement of the fiber-matrix adhesion, observed by the reduction on the hydrophilic tendency of fique fibers. The hydrophilicity has been analyzed by following the variation of the polar component of the free surface energy, calculated by the Owens-Wendt method.