The Effect of Alkali Treatment on Dielectric Properties of Roystonea regia/Epoxy Composites

The present study investigates the electrical conductivity and dielectric properties of untreated and alkali-treated Roystonea regia natural fiber-reinforced epoxy composites at different frequencies along with compression and water absorption properties. Fiber was treated with 5% NaOH and characterized by chemical, thermogravimetric, tensile test, and SEM methods before and after alkali treatment. The interface between matrix and fiber was studied by SEM. Conductivity of alkali-treated fiber composites is lower than that of untreated fiber composites and increased with increase in frequency. The dielectric constant and loss tangent values of the composites were found to decrease after alkali treatment, and these values decreased with increase in frequency. Alkali-treated fiber composites showed improvements in compressive strength and water resistance when compared with untreated fiber composites.