Strengthening Abaca Fiber-Polymer Composite via Fiber Surface Modification

The interfacial interaction of abaca fiber and unsaturated polyester matrix was modified through chemical treatments using nitric acid and acetic anhydride. The natural fibers were treated at varying concentrations of these chemicals and varying treatment duration before they were unidirectionally embedded in the unsaturated polyester matrix. Mechanical testing was done both on the natural fibers and the composites to investigate the effect of the treatment procedures. Microscopy analyses were also performed for morphological characterization of the fibers and fracture surface analysis of the composite products - after mechanical testing. It was shown that both treatments can increase the tensile strength of the natural fibers but it was the acetic anhydride that affected the higher increase both of the natural fiber and the composites at 5 volume % loading. Microscopy analyses revealed an improved fiber-matrix contact after chemical treatment that gave way to increased mechanical bonding as evident at the interface.