THE EFFECT OF FIBER REINFORCEMENT ON FRACTURE TOUGHNESS ASSESSMENT OF NANOCLAY FILLED POLYMER COMPOSITES

This paper represents the nanomechanical properties of various loading levels of montmorillonite clay filled polyester composites and randomly distributed jute fiber reinforced hybrid composites through Vickers micro-hardness test. The study of indentation fracture mechanics in polymer materials is a simple and cost-effective technique for the determination of fracture toughness. Ultrasonication technique was used to disperse the clay in the polyester matrix. The hand layup method was adapted to prepare the test specimens. Incorporation of 5 wt.% montmorillonite clay into the polymer matrix results in an enhancement in hardness of 26.52% and the modulus of elasticity increased from 4205.21 MPa for neat polyester to 5051.46 MPa with the addition of clay. Fracture toughness was observed to depend on the montmorillonite clay content, and the maximum value was observed at 5 wt.% nanoclay and 25 wt.% jute fibers. The results show that the increase in the fiber content reduces the crack propagation in hybrid composites and increases the fracture toughness. To predict the crack size, the scanning electron microscope images are used.