Effect of ionic liquid-containing poly(ε-caprolactone) on the dispersion and dielectric properties of polymer/carbon nanotube composites

Abstract

Supramolecular chemistry is a reliable and effective field that encompasses the functionalization of carbon nanotubes (CNTs) through non-covalent interactions, such as π–π stacking and cation–π interactions. In this work, poly(ε-caprolactone) (PCL) containing an ionic liquid group was synthesized through ring-opening polymerization of ε-caprolactone by using a hydroxylated ionic liquid derived from imidazole and 2-bromoethanol. Ionic liquid-containing PCL exhibited affinity for the π-conjugated structure in CNTs. The fabricated PCL/CNTs composite showed improved CNTs dispersion because of the addition of ionic liquid-containing PCL as a compatibilizer. The composites also demonstrated enhanced electronic and dielectric properties as a result of the excellent interfacial control by the compatibilizer, which could be due to the anchoring of PCL chains onto the CNTs surface via non-covalent (supramolecular) functionalization. This simple approach provides novel supramolecular tools for using renewable resources to prepare CNTs-based composites with high performance.