Self-Healing Properties of Water Tree with Microcapsule/Cross-Linked Polyethylene Composite Material Based on...

Area of Science:

• Materials Science
• Polymer Science
• Electrical Engineering

Background:

• Water tree aging degrades the insulating properties of cross-linked polyethylene (XLPE).
• Existing XLPE materials lack inherent self-repair capabilities against such degradation.
• Microcapsule systems offer a potential solution for self-healing materials.

Purpose of the Study:

• To develop and evaluate a self-repairing XLPE material using a microcapsule system.
• To investigate the effect of microcapsule doping concentration on XLPE's electrical properties and water tree resistance.
• To assess the self-healing efficiency of microcapsules in repairing water tree damage.

Main Methods:

• Preparation of three-layer shell nucleus microcapsules/XLPE composites with varying doping concentrations.
• Water tree aging experiments using the water-needle electrode method.
• Analysis of electrical properties (breakdown strength, dielectric loss factor, space charge density) and self-healing effects.

Main Results:

• High microcapsule doping concentrations led to significant degradation of electrical properties.
• At 1.0 wt% doping, microcapsule/XLPE composites showed no significant change in breakdown strength or dielectric loss.
• Space charge density decreased, indicating improved space charge properties, and microcapsules effectively filled water tree cavities upon rupture.

Conclusions:

• Microcapsule-based self-repairing XLPE demonstrates effective healing of water tree damage.
• An optimal doping concentration (1.0 wt%) enhances electrical properties and self-healing without detrimental effects.
• Surface nano-SiO2 on microcapsules improves matrix integration and repair rate, mitigating aggregation issues.