Investigation of Cyclic Stability and Pyro-Resistive Properties in High-Density Polyethylene/Tungsten Carbide Composites Under Thermal and Electric Activation

The investigation of cyclic stability holds paramount significance in the realm of conductive polymer composites (CPCs), specifically in applications related to overcurrent protection, self-heating, and sensors. This study employs a melt-blending methodology to synthesize CPCs comprising high-density polyethylene (HDPE) and tungsten carbide (WC), with a focus on identifying the key factors influencing cyclic stability. A comparative analysis is conducted between two triggering mechanisms: external thermal activation and electric heating. The CPCs demonstrate a pronounced positive temperature coefficient (PTC) and exceptional cyclic stability when subjected to external thermal triggering. Subsequent to the electrical triggering of the composite material, the resistance change rate exhibits an increase with a rising impact voltage. Moreover, the rate of resistance variation correlates positively with a reduction in the WC content. Utilizing the dielectrophoresis theory model, this study scrutinizes alterations in the conductive network under an electric field, revealing agglomeration tendencies among particles of the CPCs. Significantly, the introduction of self-cross-linking agents proves effective in mitigating this phenomenon. Consequently, beyond ensuring external thermal cyclic stability, as well as that under electric field conditions, this emerges as a pivotal consideration in the realm of CPCs.