Liquid-Crystalline Epoxy Thermosets as Matrices for Ordered Nanocomposites: A Summary of Experimental Studies

This work focuses on obtaining ordered liquid crystalline epoxy networks and applying them as matrices for nanofillers. The article summarizes research carried out by us on the synthesis and curing of a series of composites based on liquid crystalline epoxy monomers. The authors experimented with several factors which influence the crosslinking reaction and determined curing conditions which are the most favorable for developing liquid crystalline-like molecular order in the final products. New results of curing selected mixtures with the addition of anisotropic fillers are also presented. The crosslinking process was followed by differential scanning calorimetry (DSC) measurements and the morphology of liquid crystalline epoxy resin (LCER) composites was investigated by wide-angle X-ray scattering technique (WAXS-2D). The experiments demonstrated that nanorods only have a small impact on the thermal properties of the composite (e. g., the change of Tg is just about 2 degrees C) as well as structural ones (diffraction images of the plain matrix and the nanocomposite only differ in a single additional reflection near 0.73 nm(-1) which appears in all the studied matrices containing nanorods). In one case monodomain ordering could be achieved in both the matrix alone and that with the nanofiller, when curing was conducted in the presence of a magnetic field. (C) 2015 Society of Plastics Engineers