As a specialty synthetic rubber, ethyl silicone rubber maintains excellent elastic and mechanical properties even in extremely cold environments below -60°C. The core of its cold resistance lies in the synergistic effect of molecular structure design and performance control.
From a molecular perspective, the backbone of ethyl silicone rubber is composed of silicon-oxygen bonds, with a bond energy of up to 443 kJ/mol, far exceeding that of carbon-carbon bonds. This structure imparts excellent flexibility to the backbone. Furthermore, the ethyl side chain substituents offer less steric hindrance and weaker intermolecular forces than the methyl groups in methyl silicone rubber, making the molecular chain less susceptible to rigid freezing at low temperatures. When the ambient temperature drops suddenly, the molecular chain maintains a certain degree of rotational freedom, preventing the rubber from losing its elasticity due to the glass transition.
In addition, in industrial production, its cold resistance is further enhanced through optimized polymerization processes and formulation modifications. Using low-molecular-weight polydiethylsiloxane as a plasticizer can lower the glass transition temperature of the rubber system. Introducing a small amount of reactive groups, such as vinyl groups, for crosslinking ensures crosslink density without excessively restricting molecular chain motion. In applications such as seals and cable sheaths in extremely cold regions, ethyl silicone rubber, with this characteristic, can effectively resist the brittle damage to the material caused by low temperature, ensuring the stable operation of equipment in severe cold environments, and becoming one of the key materials in the fields of aerospace, polar scientific research, etc.