Changes in the Electrophysical Parameters of Nanomodified Elastomers Caused by Electric Current’s Passage

Abstract

The development of reliable and effective functional materials that can be used in various technological fields and environmental conditions is one of the goals of modern nanotechnology. Heating elements’ manufacturing requires understanding the laws of heat transfer under conditions of different supply voltages, as this expands the possibilities of such materials’ application. Elastomers based on silicon-organic compounds and polyurethane modified with multi-walled carbon nanotubes (MWCNTs) were studied at various concentrations of Ni/MgO or Co-Mo/MgO and voltages (220, 250, and 300 V). It was found that an increase in voltage from 220 to 300 V leads to an initial increase in specific power on one-third followed by a subsequent decrease in a specific power when switched on again to 220 V (for −40 °C) of up to ~44%. In turn, for a polyurethane matrix, an increase in voltage to 300 V leads to an initial peak power value of ~15% and a decrease in power when switched on again by 220 V (for −40 °C) to ~36% (Ni/MgO -MWCNT). The conducted studies have shown that the use of a polyurethane matrix reduces power degradation (associated with voltage surges above 220 V) by 2.59% for Ni/MgO–based MWCNT and by 10.42% for Co-Mo/MgO. This is due to the better heat resistance of polyurethane and the structural features of the polymer and the MWCNT. The current studies allow us to take the next step in the development of functional materials for electric heating and demonstrate the safety of using heaters at a higher voltage of up to 300 V, which does not lead to their ignition, but only causes changes in electrophysical parameters.

Facile microwave synthesis of multi‐walled carbon nanotubes for modification of elastomer used as heaters

“…The electrical conductivity of the nano‐modified composite with MWCNTs (Figure 9) showed the percolation threshold equal to 5 wt% and the critical conductivity index ( t ) as 2.3. MWCNTs synthesized by the microwave method had differences in the electrical conductivity concerning MWCNTs synthesized by the CVD method 35 . This is manifested in the improved electrical conductivity on an identical polymer matrix (organosilicon compound) due to the decarburization of MWCNTs with a layer of iron.…”

“…The degradation of conductive structures in the polymer matrix was considered in this study 35 . The results of changes in the specific power of heat discharge are given in Figure 10A,B.…”

“…MWCNTs synthesized by the microwave method had differences in the electrical conductivity concerning MWCNTs synthesized by the CVD method. 35 This is manifested in the improved electrical conductivity on an identical polymer matrix (organosilicon compound) due to the decarburization of MWCNTs with a layer of iron. The coating of MWCNTs with iron led to improved electrical charge transport due to the formation of a dense continuous coating of most of the MWCNTs.…”

“…The degradation of conductive structures in the polymer matrix was considered in this study. 35 The results of changes in the specific power of heat discharge are given in Figure 10A,B. These results are of an organosilicon matrix and MWCNTs; obtained by the microwave and CVD (NiMg catalyst) methods.…”

A Comprehensive Review on the Thermal Stability Assessment of Polymers and Composites for Aeronautics and Space Applications

“…Polymers such as organosilicon elastomers (silicones) have been extensively investigated, demonstrating their remarkable thermal resistance capabilities [ 66 , 67 , 68 ]. Zhang et al performed a numerical study on the heat transfer behavior of polydimethylsiloxane (PDMS)-based materials filled with graphene foam (GF) [ 69 ].…”