Understanding Trap Effects on Electrical Treeing Phenomena in EPDM/POSS Composites.

Area of Science:

• Materials Science
• Electrical Engineering
• Polymer Science

Background:

• Electrical degradation and treeing are critical failure mechanisms in polymer insulation.
• Polyhedral oligomeric silsesquioxane (POSS) offers superior dielectric properties compared to traditional nano-silica.
• Enhancing ethylene propylene diene monomer (EPDM) insulation is crucial for extending the lifetime of electrical components.

Purpose of the Study:

• To investigate the electrical treeing phenomena in EPDM/octavinyl-POSS (OVPOSS) composites.
• To evaluate the impact of POSS incorporation on the physicochemical properties and trap distributions of EPDM.
• To determine the optimal POSS content for improved dielectric performance and electrical tree suppression.

Main Methods:

• Characterization of chemical structure and physical dispersion using ATR-IR and SEM.
• Study of electrical treeing characteristics using a needle-plane electrode setup.
• Analysis of trap level distributions via surface potential decay (SPD) tests.

Main Results:

• The 3 wt% EPDM/OVPOSS composite demonstrated superior electrical tree growth restraint compared to neat EPDM.
• Incorporation of 3 wt% OVPOSS created deeper trap energy levels and higher trap densities.
• Suppressed charge carrier transport and polymer degradation were observed in the optimized composite.

Conclusions:

• EPDM/OVPOSS composites, particularly at 3 wt% loading, effectively suppress electrical treeing in EPDM insulation.
• The enhanced dielectric performance is attributed to increased deep trap density, hindering charge carrier movement.
• Understanding trap distributions and polarity effects is key to designing advanced polymer dielectrics.