Effect of various water immersions on mechanical properties of roselle fiber-vinyl ester composites

In the present communication, the effect of water absorptions on mechanical properties of roselle fiber reinforced vinyl ester composites prepared by wet hand lay-up method was studied. Water absorption tests were conducted by immersing composite specimens into three different water environments, namely distilled water, ground water, and sea water, which were at room temperature, for a period of 10 days. The water absorption behavior of composite was found to follow a non-Fickian behavior. The maximum water absorption percent and diffusion coefficient were determined from the obtained water absorption curves. The scanning electron microscopy was used for the fractographic studies on the fractured surface of composite. The results show that composites exposed to sea water environment absorb more water absorption percent than that of other water environments. It was observed that the water absorption percent increased with increasing fiber loading. Mechanical properties of dry composite specimens were compared with wet composite specimens. Mechanical properties were found to decrease with an increasing percentage of water uptakes. POLYM. COMPOS., 36:1638-1646, 2015. (c) 2014 Society of Plastics Engineers