Influence of moisture absorption on the impact properties of flax, basalt and hybrid flax/basalt fiber reinforced green composites

Several studies have been carried out over recent years with the aim of obtaining ecofriendly, biodegradable, low cost, lightweight natural fiber reinforced polymer composites. In this article, two types of natural fibers, basalt and flax, together with their hybridization, have been used to reinforce a green vinyl ester matrix in a wet hand lay-up lamination. The hybrid composite, with flax fiber reinforcement (FFR) in the central zone and basalt fiber reinforcement (BFR) in the outer layers, was intended for construction of boats and yachts. The influence of BFR and FFR on the impact properties of dry and salt-water conditioned composite samples has been investigated. In particular, a comprehensive scanning electron microscope (SEM) analysis of the damaged surface and cross section has been undertaken in order to investigate the mechanisms of energy absorption. The results show significant impact behavior improvements for hybrid composites compared to single composites, especially in the case of conditioned samples.