I. Basic Electrical Performance Parameters
Dielectric Strength: Phenyl silicone rubber has a dielectric strength exceeding 20 kV/mm, and its electrical performance fluctuates less than 5% within the temperature range of -50°C to 200°C.

1. High-phenyl silicone rubber (phenyl content ≥30%) exhibits enhanced molecular rigidity and excellent radiation resistance, maintaining stable insulation properties even in extreme environments.
Volume Resistivity: Low-phenyl silicone rubber (phenyl content 5-15%) has a room-temperature volume resistivity >10¹⁶Ω·m, comparable to that of ordinary silicone rubber, but exhibits superior low-temperature resistance (curing temperature up to -115°C).

II. Performance in High-Voltage Equipment Applications
Sealing and Insulation Synergy: In equipment such as large transformers and high-voltage switches, phenyl silicone rubber seals provide both physical sealing and corona discharge suppression through uniform electric field distribution. For example, Wacker Chemie's conductive silicone rubber (ELASTOSIL® N 9189) effectively dissipates charge accumulation with its 10Ω·cm volume resistivity.

Adaptability to Extreme Environments:
Temperature Resistance: Medium-phenyl silicone rubber (15-25% phenyl) maintains elasticity in the -100°C to 250°C range, making it suitable for high-voltage equipment subjected to alternating hot and cold temperatures.

Aging Resistance: After adding phenyl siloxane and a light stabilizer, the tensile strength retention rate was ≥90% after 500 cycles of temperature cycling from -40°C to 150°C.

III. Typical Application Scenarios
Power Equipment: Used in cable shielding and insulators to prevent flashover and improve operational stability.

New Energy Vehicles: In high-voltage wiring harness encapsulation solutions, phenyl silicone rubber, through flame retardant modification (UL94 V-0 rating) and chemical resistance (volume change rate ≤5%), ensures secure sealing in 300-1000V voltage systems.

IV. Performance Optimization Directions
By adjusting the phenyl content (e.g., 15-25% for medium-phenyl silicone rubber), we can balance cold resistance, flame retardancy, and processing difficulty to meet the customized requirements of different high-voltage equipment.