Performance evaluation of basalt/hemp/carbon fiber-reinforced hybrid polymer composites incorporating mineral and natural fillers

Abstract

There have been several efforts on designing hybrid polymer composites using both natural and synthetic reinforcements to harness the potential of combining sustainable aspects of natural fibers and engineering properties of synthetic materials. In this research work, hybrid epoxy composites were fabricated by adding constant amounts of calcium carbonate and coconut shell fillers along with hemp, carbon, and basalt fibers. For testing the effect of fiber hybridization on mechanical properties, moisture resistance and erosive wear behavior, nine different hybrid epoxy composites having variable reinforcement proportions were fabricated. Mechanical properties including tensile strength, flexural strength, and impact strength were evaluated following standard ASTM testing procedures to find the optimal reinforcement arrangement. In the fabricated specimens, hybrid composite containing 20 wt% of treated hemp fiber and 6 wt% of basalt fiber possessed the best mechanical properties with higher values of tensile strength, flexural strength, and impact strength. Water absorption tests showed that the optimized hybrid composites absorbed water at a relatively low rate due to effective reduction of microvoids by hybrid filler. The results of solid particle erosion tests revealed that the composites having carbon and basalt fiber reinforcement exhibited relatively better resistance against erosive wear especially at lower impingement angles. Scanning electron microscopic investigations showed a homogenous distribution of fibers, improved fiber-matrix interfacial bonding and reduction of structural defects in hybrid composite specimens. It can be concluded from this investigation that hybridizing natural and synthetic reinforcements along with fillers significantly improves the performance of epoxy based hybrid composites.

Graphical Abstract