Effect of the Simultaneous Addition of Polycaprolactone and Carbon Nanotubes on the Mechanical, Electrical, and Adhesive Properties of Epoxy Resins Cured with Ionic Liquids

Abstract

Electrically-conductive epoxy nanocomposites (NCs) with improved mechanical and adhesive properties were achieved through the combined addition of poly(ε-caprolactone) (PCL) and carbon nanotubes (CNTs). Three different ionic liquids (ILs) were used as dual role agents, i.e., as both curing and dispersing agents. Regardless of the IL used, the epoxy/PCL matrix of the NCs showed a single-phase behaviour and similar glass transition (Tg) and crosslinking density (νe) values to the unfilled epoxy/PCL/IL systems. Although the CNTs were more poorly dispersed in the epoxy/PCL/CNT/IL NCs than in the reference epoxy/CNT/IL NCs, which led to slightly lower electrical conductivity values, the epoxy/PCL/CNT/IL NCs were still semiconductive. Their low-strain mechanical properties (i.e., flexural modulus and flexural strength) were similar or better than those of the reference epoxy/IL systems and their high-strain mechanical properties (i.e., deformation at break and impact strength) were significantly better. In addition, the positive effects of the PCL and the CNTs on the adhesive properties of the epoxy/IL system were combined. The substitution of ILs for traditional amine-based curing agents and biodegradable PCL for part of the epoxy resin represents an important advance on the road towards greater sustainability.

Graphene Oxide Facilitates Transformation of Waste PET into MOF Nanorods in Ionic Liquids

“…By introducing structural and chemical functionalities on either or both cationic and anionic parts, it is possible to design "task specific" or tunable ILs with targeted properties and functions [18]. Moreover, the ability of ILs exist as either liquid or visco-elastic liquids over a wide range of temperatures and pressures have garnered significant attention in applications such as carbon dioxide sequestration [19], compatabilizers in polymer blends [20], anti-corrosion coatings [21], packaging [22], curing agents in polymers [23], polymer gel electrolytes [24], lignin fractionation [25], etc.…”