Electromagnetic and mechanical properties of La(NO₃)₃-doped multi-walled carbon nanotube/epoxy resin composites

La(NO₃)₃-doped MWCNT/epoxy resin (EP) composites were prepared by a solution bending method.Acid-oxidized MWCNTs were first used to adsorb La(NO₃)₃ and were then mixed with EP as matrix and ethylenediamine as a curing agent. The microstructure and morphology of the MWCNTs and MWCNTs-La(NO₃)₃ were investigated by TEM and XRD. The electromagnetic wave absorption properties, curing behavior and mechanical properties of MWCNT/EP and MWCNT-La(NO₃)₃/EP composites were measured by a vector network analyzer, differential scanning calorimetry, an electronic universal tester and a pendulum impact tester. Results indicate that the complex permittivity and permeability of the MWCNTs doped with La(NO₃)₃ are much improved, leading to a substantial increase in the dielectric and magnetic loss of the La(NO₃)₃-doped MWCNT/EP composite in the frequency range from 8.2 to 12.4 GHz and therefore an increase of its electromagnetic wave absorption. The curing rate of EP is accelerated by both the MWCNTs and La(NO₃)₃. The mechanical properties of the MWCNT/EP composite are degraded only slightly by the La(NO₃)₃ doping.