Study on insulating properties of polyethylene terephthalate/montmorillonite nanocomposites

Photovoltaic (PV) power is one of the most effective green energies, which has attracted extensive attention from the industry and the international community. Polyethylene terephthalate (PET) is the main material of the PV backsheet, providing insulation protection for PV modules. Although PET has excellent optical properties, weather resistance, and chemical resistance, its relatively weak insulation properties restrict its application in engineering plastic. In this paper, the insulating properties of PET/montmorillonite (MMT) are studied. PET/MMT nanocomposites with an MMT content of 1%, 3%, and 5% are prepared by the melt blending method, and their insulating properties are tested. The results show that the addition of MMT can change the distribution of the electric field inside PET, thus, increasing the breakdown voltage. Furthermore, it can reduce the number of times of partial discharge (PD) and weaken the intensity of PD in PET/MMT composites to some extent. When the MMT content is 3%, PET/MMT composites have the best insulation performance. This study can provide a reference for the application of nanocomposites in the field of green energy.