CPE is a saturated rubber without carbon-carbon double bonds, so sulfur vulcanization cannot achieve crosslinking. Only two mature industrial processes are available:
1. Peroxide Crosslinking (Mainstream, Recommended for Cables)
· Vulcanizing agents: DCP, Bis-BP; 2.7~5.4 phr DCP is added per 100 phr CPE.
· Compounded with TAIC/TAC co-crosslinkers to greatly improve crosslink density, heat resistance and tensile strength.
· Advantages: Excellent thermal aging resistance, low compression set, oil resistance and weather resistance, ideal for long-term outdoor rubber-sheathed cables.
1. Radiation Crosslinking (High-End Thin-Wall Wires) No vulcanizing agent required; crosslinked by electron beam irradiation. No blooming on product surface, heat resistance up to 105℃/125℃, applicable to power cords and UL-certified wires.
Thiourea/thiadiazole systems are prohibited: poor aging resistance and large permanent deformation, only used for low-cost rubber miscellaneous parts, never for cables.
