The influence of a magnetic field on the morphology and thermomechanical properties of a liquid crystalline epoxy carbon composite

The synthesis of a novel ordered liquid crystalline epoxy carbon composite was presented in this article. Anthracite thermally modified at 2,000 degrees C (SV2000) having graphitic structure was used as a filler in the composite with matrix obtained by crosslinking a liquid crystalline diepoxy monomer LCEM containing triaromatic mesogenic group. The curing agent was 4,4 '-diaminodiphenylmethane. The morphology and thermomechanical properties of the final products were characterized by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and wide angle X-ray scattering (WAXS) analysis. It was found by WAXS measurements that alignment of LCEM was effectively induced in the matrix and in the composite filled with SV2000 by applying external magnetic field during cure. Thermosets with locked smectic C structure were obtained in all cases, with mesogenic fragments arranged along the applied field. The experimental results indicated that the presence of SV2000 as the filler of composite partially decreased the degree of order. The oriented composites exhibited anisotropy of the dynamic-mechanical properties. POLYM. COMPOS., 39:E2573-E2583, 2018. (c) 2018 Society of Plastics Engineers