Influence of Crosslink Density on Electrical Performance and Rheological Properties of Crosslinked Polyethylene

Abstract

To investigate the influence of the crosslinked polyethylene (XLPE) structure on electrical performance, various analytical methods were employed to study polyethylene structures with different degrees of crosslinking. Dynamic rheological analysis was conducted to determine material shear viscosity, dynamic viscosity, storage modulus (G′), loss modulus (G″), and other rheological parameters. Additionally, the electrical performance of the material was analyzed by studying the phenomenon of space charge accumulation under direct current voltage. The results indicate that with an increasing mass fraction of the crosslinking agent, the crosslink density of crosslinked polyethylene initially increases and then decreases. When the dicumyl peroxide (DCP) content exceeds 1.0 wt.%, there is an accumulation of like-polarity space charges. The best rheological processing performance of crosslinked polyethylene is observed when the DCP content is in the range of 1.0–1.5 wt.%.

Hierarchical Structural Evolution, Electrical and Mechanical Performance of Polypropylene Containing Intrinsic Elastomers under Stretching and Annealing for Cable Insulation Applications

“…5−7 However, there is an irreconcilable contradiction between the intrinsic thermoset features of XLPE and the increased worldwide awareness of sustainable development. 8,9 The thermoplastic polypropylene (PP) insulated cables have become an attractive alternative to substitute traditional cable insulated with XLPE, originating from a series of advantages of PP insulation, such as excellent insulation performance, high operating temperature, brilliant recyclability, fast manufacturing processing with reduced cost, and unlimited cable length without considering scorch phenomena. 10−12 Unfortunately, the brittleness at low temperatures and the lack of flexibility at room temperature for PP can hardly meet the requirement of mechanical properties for cable insulation materials.…”

“…Over the past decades, great development of high-voltage power transmission technologies has been achieved to accommodate the intensely increasing demand for renewable energy and long-distance power transmission. − Extruded cables based on cross-linked polyethylene (XLPE) insulation materials have attracted extensive attention in the field of electric power delivery due to their excellent thermo-mechanical properties and electrical behavior at high temperatures. − However, there is an irreconcilable contradiction between the intrinsic thermoset features of XLPE and the increased worldwide awareness of sustainable development. , The thermoplastic polypropylene (PP) insulated cables have become an attractive alternative to substitute traditional cable insulated with XLPE, originating from a series of advantages of PP insulation, such as excellent insulation performance, high operating temperature, brilliant recyclability, fast manufacturing processing with reduced cost, and unlimited cable length without considering scorch phenomena. − Unfortunately, the brittleness at low temperatures and the lack of flexibility at room temperature for PP can hardly meet the requirement of mechanical properties for cable insulation materials. , For instance, the elastic modulus of PP is up to 1.6 GPa, while it is encouraged to be reduced to lower than 600 MPa. To address the emerging challenge, a growing body of research on PP insulation materials has been conducted to balance their thermo-mechanical and electrical performance.…”