Properties of Organosilicon Elastomers Modified with Multilayer Carbon Nanotubes and Metallic (Cu or Ni) Microparticles

The structural and electro-thermophysical characteristics of organosilicon elastomers modified with multilayer carbon nanotubes (MWCNTs) synthesized on Co-Mo/Al O -MgO and metallic (Cu or Ni) microparticles have been studied. The structures were analyzed with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). The main focus of this study was the influence of metallic dispersed fillers on the resistance of a modified elastomer with Cu and Ni to the degradation of electrophysical parameters under the action of applied electrical voltage. The distribution of the temperature field on the surface of a modified polymer composite with metallic micro-dimensional structures has been recorded. The collected data demonstrate the possibility of controlling the degradation caused by electrical voltage. It has been found that repeated on/off turns of the elastomer with an MWCNTs on 50 and 100 cycles leads to a deterioration in the properties of the conductive elastomer from the available power of 1.1 kW/m (-40 °C) and, as a consequence, a decrease in the power to 0.3 kW/m (-40 °C) after 100 on/off cycles. At the same time, the Ni additive allows increasing the power by 1.4 kW/m (-40 °C) and reducing the intensity of the degradation of the conductive structures (after 100 on/off cycles up to 1.2 kW/m (-40 °C). When Ni is replaced by Cu, the power of the modified composite in the heating mode increases to 1.6 kW/m (-40 °C) and, at the same time, the degradation of the conductive structures in the composite decreases in the mode of cyclic offensives (50 and 100 cycles) (1.5 kW/m (-40 °C)). It was found that the best result in terms of heat removal is typical for an elastomer sample with an MWCNTs and Cu (temperature reaches 93.9 °C), which indicates an intensification of the heat removal from the most overheated places of the composite structure. At the same time, the maximum temperature for the Ni additives reaches 86.7 °C. A sample without the addition of a micro-sized metal is characterized by the local unevenness of the temperature field distribution, which causes undesirable internal overheating and destruction of the current-conducting structures based on the MWCNTs. The maximum temperature at the same time reaches a value of 49.8 °C. The conducted studies of the distribution of the micro-sizes of Ni and Cu show that Cu, due to its larger particles, improves internal heat exc