Polypropylene‐based soft ternary blends for power cable insulation at low‐to‐high temperature

Abstract

Although cross-linked polyethylene (XLPE) has been widely used as a power cable insulation material in electricity infrastructure for decades, it is necessary to find alternatives that exhibit higher performance than XLPE to meet the increasing demand of the industry. To this end, polypropylene (PP) ternary blends that are soft and exhibit high temperature stability were fabricated by melt blending isotactic PP, ethylene-1-octene polyolefin elastomer and ethylene-propylene random copolymer. These blends exhibited improved higher impact resistance at low temperatures (À40 C) and room temperature than pristine iPP. The blends were mechanically stable even when the temperature was increased to ~120 C, unlike XLPE that exhibited rapid degradation of its modulus above ~90 C. Moreover, the soft ternary blends exhibited increased direct current volume resistivity and breakdown strength. Our work realizes the development of high-performance insulators for power cables that can be used over a wide range of temperatures from cold to hot environments.

Polyvinylidene fluoride dopant as voltage stabilizer for improving high-voltage insulation properties of polypropylene

“…We also measured the direct current breakdown strength (DC BDS) of the samples at 110°C, the normal operating temperature of the high-voltage power cables, as shown in Fig. 4b [33]. The BDS values of iPP and PVDF decreased to approximately 160 and 30 kV/mm, respectively, owing to the loss in elasticity depending on temperature [34].…”

The influence and mechanism of elastomer types on electrical and mechanical properties of polypropylene insulation materials for high voltage cables

“…Due to its poor toughness 8 and accumulation of space charges, PP 9 cannot be directly applied in highvoltage cables, and its mechanical and electrical properties need to be improved. [10][11][12] At present, the modification methods for PP can be divided into two categories: chemical [13][14][15][16] and physical modification. [17][18][19][20][21] Commonly used chemical modifications are copolymerization 13,14 and grafting modification, 15,16 and so on.…”

Polystyrene: A Self-Dispersing, Ultralow Loading Additive for Improving the Breakdown Strength of Polypropylene for High Voltage Power Cable Applications

“…5 However, a rise in applied voltage required for high capacity causes an increase of the operating temperature that is expected to exceed the workable temperature of the XLPE, and hence it would reach its breaking point. 6 To replace the existing XLPE, polypropylene (PP) has recently received great attention as an insulation material for HV power cables because it has excellent mechanical and electrical properties, high-temperature stability, and processability without additional cross-linking. 7,8 To be used as a power cable material, however, the poor impact resistance and a high elastic modulus arising from the intrinsic rigidity of the PP molecules should be improved and reduced, respectively.…”

“…In modern society, the proportion of energy that is renewable is rising to address earth environmental issues such as carbon neutrality. , To globally share the electricity obtained from renewable energyknown as supergrid, direct current (DC) power transmission capable of accepting higher power capacity is required, and the demand for ultrahigh voltage (HV) DC power cables is rapidly increasing. , Over the past few decades, cross-linked polyethylene (XLPE) has been widely used as an insulation material due to its advantageous mechanical, electrical, and thermal properties suitable for power cable applications . However, a rise in applied voltage required for high capacity causes an increase of the operating temperature that is expected to exceed the workable temperature of the XLPE, and hence it would reach its breaking point …”