Phenyl raw rubber is a key raw material for preparing high-performance phenyl silicone rubber, and seals made from it play a crucial role in automotive exhaust systems. Its primary function is to provide a durable and reliable seal under extreme high temperatures and vibrations, preventing the leakage of harmful exhaust gases.

Core Function: Coping with Extreme Conditions
Automotive exhaust systems, especially those near the engine, operate in extremely harsh environments. Phenyl silicone rubber seals are able to perform this task primarily due to the following key properties:

Excellent High-Temperature Resistance
The exhaust system operates at extremely high temperatures. Ordinary rubber materials would rapidly age, harden, or even carbonize under these conditions, leading to seal failure. Phenyl silicone rubber, however, can operate stably at temperatures above 250°C for extended periods and can withstand short-term thermal shocks up to 400°C, ensuring good elasticity and sealing performance even under extreme conditions.

Excellent Wide Temperature Range Elasticity
In addition to high-temperature resistance, the exhaust system cools to ambient temperature after the vehicle is turned off, especially in winter when temperature fluctuations are significant. Phenyl silicone rubber (especially low-phenyl content varieties) has a glass transition temperature (Tg) as low as -100℃ and does not harden or become brittle at extremely low temperatures. This ability to maintain elasticity over a wide temperature range ensures that the seals effectively fill gaps and prevent leakage throughout the entire process, from cold start to high-temperature operation.

Excellent Chemical Corrosion Resistance
Exhaust gases contain various corrosive chemicals. Phenyl silicone rubber, with its stable chemical structure, effectively resists the erosion of these chemicals and is not prone to swelling or degradation, thus ensuring a long service life for the seals.

Main Application Scenarios
Based on the above characteristics, phenyl silicone rubber seals are mainly used in critical connection points of the exhaust system:
* Exhaust Manifold/Exhaust Pipe to Cylinder Head Connection: This is the first point of contact for high-temperature exhaust gases leaving the engine, with the highest temperature, making it the most typical application scenario for phenyl silicone rubber seals, usually appearing in the form of exhaust pipe gaskets.

* Exhaust Pipe Connections: Used for flange connections between components such as mufflers and catalytic converters to prevent exhaust gas leakage in the pipeline.

In summary, phenyl raw rubber gives rubber materials the ability to work in the extreme environments of automotive exhaust systems, and the seals made from it are key components for ensuring vehicle emission safety, preventing environmental pollution, and ensuring the safety of drivers and passengers.