Study on properties of polyurea resin curing system based on unbalanced molar ratio

Abstract The construction of local insulating protective layers on transmission towers and their cross-arm structures can significantly improve the insulating performance of their gaps and thus reduce the risk of gap breakdown accidents. In this study, six polyurea resin materials with different molar ratios were successfully prepared, and the polyurea curing systems with non-standard molar ratios were comprehensively characterized by using Fourier transform infrared spectroscopy, scanning electron microscopy observation, and differential scanning calorimetry analysis. In addition, static contact angle tests, water absorption assessments, and AC breakdown strength tests were performed on these materials. The results of the study showed that the hydrophobicity and electrical properties of the polyurea-cured systems deteriorate when the molar ratio deviates from the standard value (i.e., 10:10). However, a positive finding is that increasing the amine content significantly reduces defects in the polyurea cured system, decreases water absorption, and improves both hydrophobicity and electrical properties. However, increasing the content of amine compounds can significantly reduce the defects in the polyurea curing system, decrease water absorption, and simultaneously improve its hydrophobicity and electrical properties.