Effect of surface treatments on interfacial properties of natural intralaminar hybrid composites

The objective of this work was to analyze the influence of the alkalization and alkalization + silanization (mixed) treatments on the interfacial adhesion and mechanical properties of intralaminar hybrid composites (jute + sisal, jute + curauá, jute + ramie, and jute + glass fiber). Single‐fiber tensile tests, fragmentation, and short beam tests were performed. Finally, a SEM analysis was used to study the influence of surface chemical treatments on the morphology of the natural fibers used. SEM images showed that the chemical treatments altered the morphology of the natural fibers. The chemical treatments improved the tensile strength of the fibers studied. It was found that the alkaline treatment is the best suited for jute, ramie, and curauá fibers, while the sisal fiber presented the best results after the mixed treatment. The superficial chemical treatments also affect the interfacial/interlaminar adhesion of the hybrid composites studied here. The best superficial treatments for each type of hybrid composite were: alkaline treatment for jute + ramie and jute + sisal, while for jute + curauá the best results were obtained for the untreated specimens.