Investigation of heat release in nanomodified elastomers during stretching and torsion under the action of electric voltage

The authors studied the elastomers modified with carbon nanotubes (MWCNTs) with a mass concentration from 1 to 8 % wt. and investigated the modes of heat release of nanomodified elastomers within the range between 30 and 260 V (of alternating current) at different levels of stretching and torsion. Samples of elastomers with the MWCNT concentration from 1 to 5 % wt. in the supply voltage range up to 260 V did not generate heat. The study showed that heat release when feeding composites of elastomers with MWCNTs was observed at a mass concentration of 6 % wt. of MWCNTs and a supply voltage of 70 V. The maximum voltage for an elastomer sample with 6 % wt. of MWCNTs reaches 260 V. An increase in concentration to 7 % wt. causes the increase in the heat release power and the decrease in the maximum supply voltage level to 180 V when the initial heat release voltage is 40 V. At the 8 % wt. concentration, the power increases, and the limiting voltage drops to 100 V, while the initial voltage becomes 36 V. The study identified that when twisting elastomer by 360°, the areas with an increased temperature on the right and in the central zone of the sample (49.5 °C) are formed. The temperature at the bend point increases up to 50.2° С when twisting elastomer by 540°. An increase in the twisting angle to 1080° leads to the formation of areas with the elevated temperature near the right-side current-carrying clamp. It is worth noting the possibility of using the produced samples of elastomers with MWCNTs as sensitive elements of strain sensors, which will allow obtaining the information on physical and chemical parameters according to the principles of measuring the change in electrical resistance that occurs during stretching and torsion.