Effect of Acetylated SEBS/PP for Potential HVDC Cable Insulation

Area of Science:

• Materials Science
• Polymer Chemistry
• Electrical Engineering

Background:

• Polypropylene (PP) blended with thermoplastic elastomers offers potential for high-voltage direct current (HVDC) cable insulation due to improved toughness.
• High loadings of thermoplastic elastomers in PP decrease electrical strength, failing to meet HVDC cable requirements.

Purpose of the Study:

• To enhance the electrical strength of PP/thermoplastic elastomer blends for HVDC cable insulation.
• To investigate the DC electrical insulation and mechanical properties of acetylated SEBS (Ac-SEBS)/PP blends.

Main Methods:

• Synthesized Ac-SEBS by introducing acetophenone units onto SEBS via Friedel-Crafts acylation.
• Investigated the DC breakdown field strength, conductivity currents, and space charge accumulation in Ac-SEBS/PP blends.
• Evaluated the tensile strength and elongation at break of the Ac-SEBS/PP blends.

Main Results:

• Doping 30% Ac-SEBS into PP significantly increased DC breakdown field strength by 22.4% due to acetophenone units absorbing high-energy electrons.
• Ac-SEBS reduced carrier mobility and conductivity currents by capturing electrons, suppressing space charge accumulation.
• Ac-SEBS maintained the toughening effect, enhancing PP's tensile strength and elongation at break.

Conclusions:

• Ac-SEBS/PP blends exhibit simultaneously excellent insulation and mechanical properties.
• The developed Ac-SEBS acts as a voltage stabilizer, enhancing the electrical performance of PP for HVDC cable insulation.
• These blends show promise as advanced insulation materials for high-voltage direct current cables.