Influence of gamma and ultraviolet radiation on the mechanical behavior of a hybrid polyester composite reinforced with curaua mat and aramid fabric

Functionalization of composite materials by ionizing radiation is considered an environmentally friendly technology to improve the compatibility of natural fibers with a polymer matrix. However, depending on the dose, it might also cause degradation. In particular, the effect of ionizing radiation on hybrid polymer composites reinforced with both naturals and synthetics fibers still needs more attention. In the present work, for the first time, the mechanical behavior of a hybrid polyester composite reinforced with 33 wt% of curaua fibers mat and 7 wt% of aramid fabric subjected to ultraviolet (UV) and gamma ionizing radiation, was investigated. Ultraviolet exposure for 300 and 600 h and gamma radiation doses of 150 and 300 kGy were applied before 3 points bending tests. The results disclose an increase in flexural strength and modulus with increasing UV when compared to other irradiated conditions. Macroscopic observation and scanning electron microscopy analysis of fractured irradiated specimens revealed delamination as the main failure mechanism.