Surface-Modified $\text{SiO}_{2}$ Nanoparticles on Thermal Aging Life of PP

In the context of realizing the country's “dualcarbon” goal, cross-linked polyethylene (XLPE) insulation materials are gradually being replaced by environmentally friendly, recyclable thermoplastic materials such as polypropylene (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{P P}$</tex>) due to their high energy consumption and environmental pollution. However, in the long-term service of the cable, the insulation layer faces the risk of aging, so the use of PP as cable insulation still needs to overcome its poor resistance to electrical aging and many other shortcomings. In order to study the thermal aging properties, dielectric properties and crystalline properties of silica/polypropylene composites. In this paper, a straight line of Arrhenius equation was fitted based on the oxidation induction time to predict the heat aging life of the materials at the actual working temperature (90° C) for each material. The <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiO}_{2} / \text{PP}$</tex> composites were also characterized by DSC and tested for dielectric properties, and the crystallinity and relative dielectric constant, loss factor of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiO}_{2} / \text{PP}$</tex> nanocomposites were obtained. The results show that the incorporation of nano- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiO}_{2}$</tex> affects the lifetime of polypropylene cable materials, with the doping of 0.8 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{wt} \%$</tex> of R 9 -type <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiO}_{2}$</tex> having the best effect on the heat aging life enhancement. The addition of nano- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiO}_{2}$</tex> also affects the melting and crystallization temperatures of polypropylene cable materials, improves the crystallinity of polypropylene cable materials, and reduces the loss factor and relative dielectric constant.