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This study aims to evaluate the influence of fiber hybridization and frequency on the dynamic mechanical properties of ramie/glass hybrid fiber-reinforced polyester composites. The storage modulus (E 0 ), loss modulus (E 00 ) and damping behavior (tan d) were evaluated as a function of different relative glass/ramie fiber volume ratios. For the storage modulus, the importance of the reinforcement effect above T g was revealed. Also, the peak height, peak width at half-height and relaxation area were investigated for the loss modulus and tan d curves, showing the influence of a shoulder below T g for each case. Finally, the tan d peak shifts to higher temperatures by increasing the frequency. Higher activation energy was observed for 75% glass fiber-containing composites.

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The use of ramie fibers as reinforcement in hybrid composites is justified considering their satisfactory mechanical properties if compared with other natural fibers. This study aims to verify changes in chemical composition and thermal stability of the ramie fibers after washing with distilled water. One additional goal is to study glass fiber and washed ramie fiber composites focusing on the effect of varying both the fiber length (25, 35, 45 and 55 mm) and the fiber composition. The overall fiber loading was maintained constant (21 vol.%). Based on the results obtained, the washed ramie fiber may be considered as an alternative for the production of these composites. The higher flexural strength presented being observed for 45 mm fiber length composite, although this difference is not significant for lower glass fiber volume fractions: (0:100) and (25:75). Also, by increasing the relative volume fraction of glass fiber until an upper limit of 75%, higher flexural and impact properties were obtained.

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