Developing new types of insulated power cable with excellent comprehensive performance and environmental friendliness has become a hot research topic in recent years. Polypropylene (PP) is a thermoplastic material with excellent electrical resistance. When applied to the insulation of power cables

it features a simple manufacturing process without the need for degassing treatment

which is conducive to energy conservation

emission reduction

and efficient utilization in power cable equipment. However

ordinary polypropylene has poor toughness and is prone to brittle fracture at low temperatures

necessitating toughening modification. This paper analyzes the structure and properties of different co-polymerization modified polypropylene

and studies the thermal

mechanical

and electrical properties of ethylene co-polymerization modified polypropylene

long-chain branched polypropylene

and polypropylene containing antioxidant components. The test results show that

after ethylene copolymerization modification

the mechanical properties of PP are significantly improved

but changes in the molecular chain structure affect the melt crystallization process of PP insulation materials and deteriorate the dielectric properties of the insulation under high-temperature conditions. Long-chain branching helps synergistically enhance the electro-thermal-mechanical properties of PP materials

reducing the average size of the rubber phase

increasing the crystallization temperature

and effectively controlling the dielectric loss tangent at high temperatures. This study can provide guidance for the development and reliable application of polypropylene cable materials.