Effect of ultraviolet radiation and water spraying on the mechanical properties of multi‐walled carbon nanotubes reinforced natural fiber and hybrid composites

The main objective of this study was to investigate the effect of aging by ultraviolet radiation and water spray on the mechanical properties of natural fiber and hybrid composites. Pure jute, hybrid jute/glass, and glass fiber‐reinforced composites were fabricated. All these types of composites were further modified with 0.6 wt% of multi‐walled carbon nanotubes (MWCNTs) and their mechanical behavior was compared to the unmodified specimens. Tensile and flexural tests were used to measure the mechanical properties of unaged (control) and aged specimens. A scanning electron microscopy analysis was used to examine the fracture surfaces of the specimens tested. It was found that the aging process affected the mechanical properties of the composites studied in different ways. For jute and jute + MWCNT composites the properties decreased with increased exposure time. The hybrid jute/glass composites (unmodified and MWCNT modified) were less affected by aging and showed an insignificant change in tensile strength. The hybrid + MWCNT composites, showed an increase of approx. 7% in Young's modulus (1000 h) and 9% (500 h) and 17%, (1000 h) in flexural modulus when compared to the unexposed specimens. The MWCNTs had a positive effect on the mechanical properties of the glass + MWCNT aged samples.