Influence of organo-modified montmorillonite nanolayers on static mechanical and dynamic mechanical behavior of carbon/epoxy composites

Abstract

The combination of carbon fiber and organo-modified montmorillonite nanolayers with epoxy matrix can produce a hybrid composite that is competitive to carbon/epoxy composites. In this work, carbon fabrics and organo-modified montmorillonite nanolayers (1.5, 3, and 5 wt%) were used to produce hybrid carbon/epoxy composites using hand lay-up technique followed by autoclave curing, aiming to evaluate their static mechanical and dynamic mechanical properties. Higher organo-modified montmorillonite content in carbon/epoxy yielded slight decrease in the weight and lower voids in carbon/epoxy composite. Transmission electron micrographs showed that the organo-modification improved the dispersion and interfacial bonding of organo-modified montmorillonite with an epoxy at loadings of 1.5 and 5 wt%. The flexural strength, interlaminar shear strength, and impact strength and modulus of the composites were improved with increasing organo-modified montmorillonite content. Carbon/epoxy composite with 5 wt% organo-modified montmorillonite had the greatest increase in mechanical properties, with the flexural modulus and strength increasing by about 33% and 27%, respectively. Although the flexural properties were improved for hybrid composites, the glass transition temperature decreased for lower organo-modified montmorillonite content up to 3 wt% and increased for 5 wt%. Dynamic mechanical analysis results revealed that the storage modulus of carbon/epoxy composite was increased significantly for 5 wt% organo-modified montmorillonite loading. However, the loss modulus was decreased for 1.5 and 3 wt% organo-modified montmorillonite loading. Also, tan δ has increased for 1.5 wt% and later decreased for 3 and 5 wt% organo-modified montmorillonite loading in carbon/epoxy hybrid composite.