High-efficiency enhancement of the surface weatherability and electrical and mechanical properties of a cycloaliphatic epoxy-based hybrid nanocomposite via reaction-induced organic functional groups

Abstract

Designing an outdoor insulation-appropriate material architecture with superior surface weatherability, hydrophobicity transfer, and electrical and mechanical properties would play an essential role in enhancing the security operations of power systems. In this work, a cycloaliphatic epoxy resin (CEP) was modified with organofluorine and organosilicon to introduce functional groups to improve its surface properties. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectral analysis showed that these functional groups were successfully introduced into the modified CEP. The characteristics of the modified CEP were assessed in terms of weather resistance, mechanical properties and hydrophobicity. The results show that the modified CEP composite surface integrates the complementary characteristics of multiple components, thereby greatly improving the surface impact toughness, hydrophobicity and weatherability. The hydrophobicity migration of the new composite was tested. The results show that a large number of hydrophobic groups (Si−CH3) migrate to the sample surface, causing self-healing of hydrophobicity, which helps prevent pollution flashover. In addition, electric insulation tests were conducted on modified CEPs with different contents of micro-nanometre fillers without affecting the mechanical properties of the composite system. The test results revealed the best combination of inorganic fillers to improve the insulation performance. The micromorphology and mechanism of interaction between the CEP-based composite and nanoparticles were analysed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermally stimulated depolarization current (TSDC) and broadband dielectric spectroscopy. This work provides an invaluable guideline for the design of outdoor insulation composite materials.