In the complex powertrain systems of hybrid electric vehicles (HEVs), the exhaust manifold faces far more stringent thermal management challenges than traditional gasoline-powered vehicles. Due to frequent engine start-stop cycles and operating condition switching, exhaust manifold seals must withstand drastic temperature shocks and sustained high-temperature environments. Traditional rubber materials often fail under such extreme conditions, while phenyl silicone raw gum, with its unique molecular structure, has become a core material ensuring the reliability of seals in this critical component.

The key to phenyl silicone raw gum's ability to fulfill this responsibility lies in the phenyl groups introduced into its molecular chain. This chemical modification endows the material with exceptional high and low temperature resistance. During cold starts at low temperatures, phenyl silicone raw gum effectively inhibits the crystallization of silicone rubber molecular chains, allowing it to maintain excellent flexibility even at temperatures as low as -40°C, preventing leaks caused by hardening and shrinkage of the seals. When the engine operates under high load, the exhaust manifold temperature can instantly soar to hundreds of degrees Celsius. Phenyl raw rubber, with its high bond energy and thermal stability due to the benzene rings, can withstand high temperatures for extended periods without thermal degradation or permanent deformation from excessive compression, ensuring a strong rebound seal at high temperatures.

Furthermore, exhaust manifold seals in hybrid systems must possess excellent oil and media resistance to resist the corrosive effects of high-temperature exhaust gases and oil mist. Phenyl raw rubber not only maintains the original insulation properties of silicone but also further enhances its resistance to complex chemical environments.

By using phenyl raw rubber as the base polymer, exhaust manifold gaskets can achieve a "rigid yet flexible" sealing effect across a wide temperature range, effectively solving the leakage and aging problems caused by frequent thermal cycling in hybrid vehicles, providing a solid material guarantee for improving overall vehicle fuel economy and reducing emissions.