Ionic liquids facilitated dispersion of chitin nanowhiskers for reinforced epoxy composites.

In this work, we propose a novel approach to produce a high-strength epoxy nanocomposite using ionic liquids facilitated dispersion of chitin nanowhiskers (CNWs). Samples with 0-3 wt% CNWs and 1 wt% of [Emim][OAc] were fabricated by mixing, casting, and curing. The morphological observations of the ethanol/ionic liquid suspensions by TEM indicated that [Emim][OAc] helped in dispersing the CNWs. The tensile, impact, dynamical mechanical properties, and thermal stability of the composites were further evaluated to access the reinforcing effect of CNWs. Increase of 35 % tensile strength, 175 % toughness and 90 % impact strength were observed upon addition of 2 wt% of CNWs. Thermal stability of the epoxy was not affected by the addition of CNWs. The SEM observations of the composites evidenced that the fracture mechanisms had changed upon CNWs addition. This work shows the advantage of the novel approach using ionic liquids as nanofiller dispersant in fabricating CNWs nanocomposites.

Chitin nano-whiskers (CNWs) as a bio-based bio-degradable reinforcement for epoxy: evaluation of the impact of CNWs on the morphological, fracture, mechanical, dynamic mechanical, and thermal characteristics of DGEBA epoxy resin.

Chitin nano-whiskers (CNWs) are high performance nanomaterials that can be extracted from chitin, which is one of the most widely available bio-resources. Herein we investigate the effect of CNWs on the morphological, mechanical, dynamic mechanical and thermal properties of DGEBA epoxy. Optically transparent, bulk epoxy nano-composites with 0.25 wt%, 0.5 wt% and 0.75 wt% CNWs were evaluated in addition to neat epoxy. The composites were prepared based on a modified slurry compounding method. CNWs appear to be well dispersed within the epoxy matrix with increasing tendency for clustering as the CNW content is increased. The addition of 0.25 wt% CNWs to neat epoxy results in a decrease in the glass transition temperature and an increase in the tensile strength, modulus, damping and thermal degradation temperature. All the composites evaluated with CNWs showed distinct crack arrest events upon initiation of the first major crack growth during fracture toughness testing. Composites with 0.75 wt% CNWs showed the highest damping and an increase in the fracture toughness and resilience over neat epoxy.