Insulation properties enhancement of crosslinked polyethylene by grafting electron‐buffering voltage stabilizers

Abstract

Grafting a voltage stabilizer on molecular chains of cross‐linked polyethylene (XLPE) can effectively improve the materials' insulation properties. Four different samples (XLPE, XLPE grafted with the voltage stabilizer, low‐density polyethylene (LDPE) blended with the voltage stabilizer, and LDPE grafted with the voltage stabilizer) are prepared in this paper. Several physicochemical and dielectric tests are performed to investigate the properties of the samples. The results demonstrate that the m‐aminobenzoic acid is successfully grafted onto the XLPE molecular chain. Moreover, the crosslinking and grafting processes are equally important for enhancing the materials' performance of the XLPE. In addition, the grafted voltage stabilizer negligibly affects the gel content and thermal properties of XLPE. However, it increases the crystallinity but decreases the lamella thickness. Moreover, the XLPE grafted with a voltage stabilizer has lower direct current (DC) electrical conductivity, less aggregation of space charge, and higher DC breakdown strength. The trap distribution results indicate that the voltage stabilizer introduces shallow traps in the sample and the quantum chemical calculations describe that the material bandgap is decreased. Thus, the high‐energy charge carriers are buffered by the newly‐introduced traps and the functional groups, leading to the enhanced material properties of the XLPE.

Improvement of Age-Resistance of LDPE-Based Nanocomposite Films by Addition of a Modified Layered Double Hydroxide with an Anionic UV Screener

“…PBS-LDH showed a much better thermal stability than PBS because the UV absorber in PE + PBS films could be partially degraded during the casting process and the sunscreen activity is enhanced in the encapsulated form. In this regard, the addition of PBS-LDH showed improved age-resistance and is a suitable option for outdoors applications such as fabrication of greenhouses [34], pipe coatings [35], or insulation [36].…”

Design of voltage stabilizers for high breakdown strength materials

“…One approach to the development of new high breakdown strength material is compounding voltage stabilizer molecules into polyethylene, which can then be further crosslinked. [2][3][4][5][6][7][8][9] Chen and co-workers 7 have also tried to use nanofillers in cross-linked polyethylene and found that the addition of nanofillers typically will decrease the electrical insulation performance. The study of voltage stabilizers has a history of more than half a century.…”