Phenylvinyl raw rubber, as a special silicone rubber material, exhibits excellent radiation resistance in the nuclear energy field. Its characteristics are analyzed in detail below from several aspects:

I. Basic Material Characteristics
Phenylvinyl raw rubber is a silicone rubber material whose molecular backbone is composed of alternating silicon and oxygen atoms (—Si—O—Si—). The side chains are hydrocarbon or substituted hydrocarbon organic groups connected to silicon atoms, including methyl, unsaturated vinyl (molar fraction generally not exceeding 0.05), or other organic groups. This special structure endows it with the following properties:

High and low temperature resistance: It maintains rubber elasticity at temperatures ranging from -70°C to -100°C, making it the rubber with the best low-temperature performance among all rubbers.

Radiation resistance: High-phenyl silicone rubber (phenyl content above 30%) has excellent radiation resistance.
Chemical stability: Insoluble in water, soluble in organic solvents such as toluene, with low compression set.
Mechanical properties: Possesses excellent physical and chemical properties, and can be made into sealing materials resistant to both high and low temperatures.


II. Types of High-Energy Irradiation in the Nuclear Field and Their Influence Mechanisms
Common types of high-energy irradiation in the nuclear field and their effects on materials:
Irradiation Type | Characteristics | Effects on Materials
α-rays | Helium nuclei, weak penetration | Mainly causes surface damage, leading to material oxidation and pulverization
β-rays | High-speed electron flow, moderate penetration | Causes molecular chain breakage and cross-linking, making the material harder and more brittle

γ-rays | High-energy electromagnetic waves, strong penetration | Causes molecular chain breakage and cross-linking, altering the crystallinity of the material

Neutrons | Uncharged, strong penetration Displacement damage occurs, forming vacancies and interstitial atomic defects.

The main mechanisms by which irradiation affects materials include: Molecular chain breakage and changes in crosslinking density; altered crystallinity and disruption of functional group integrity; material discoloration, surface chalking, and mass loss; and decreased mechanical properties (tensile strength, elongation).

III. Radiation Resistance Performance Phenyl vinyl rubber exhibits excellent radiation resistance in the nuclear field:
Radiation tolerance: High phenyl content (above 30%) significantly improves radiation resistance.
Effectively resists the long-term effects of nuclear radiation such as gamma rays and beta rays.
In nuclear power plants over 80 years... Maintains stable performance even under lifespan requirements

Performance Retention Rate: High retention rate of mechanical properties (tensile strength, elongation) after irradiation; Low compression set, suitable for long-term sealing applications; Minimal hardness change, maintaining the material's original elasticity.

Application Examples: Nuclear power plant cable sheath materials (such as alternatives to ethylene propylene rubber and ethylene-vinyl acetate copolymer); Nuclear facility seals and O-rings; Neutron shielding material assemblies.

IV. Radiation Resistance Testing and Evaluation
The radiation resistance of phenyl vinyl rubber is typically evaluated using the following methods:

Testing Standards: GB/T 26168.1, ISO Standard methods such as 11137 are used. Quantitative irradiation is performed using a cobalt-60 or cesium-137 gamma irradiation device. The irradiation dose is typically set from 1 kGy to 1000 kGy.

Key evaluation indicators:
Mechanical property changes: tensile strength, elongation at break, rate of change of stress at a given elongation; hardness changes: changes in Shore A or IRHD hardness values; compression set: assessing the material's recovery ability; volumetric or mass changes: reflecting the degree of molecular chain breakage or cross-linking.

Accelerated aging testing: Simulating long-term service environments through irradiation with different doses; establishing performance degradation models to predict material lifespan; assessing critical absorbed dose and failure dose points.

V. Technological Advantages and Development Trends
Advantages of Phenylvinyl Raw Rubber in the Nuclear Field:

Structural Advantages:
* The rigidity of the benzene ring provides excellent mechanical and thermal stability.
* Long-chain alkyl side chains impart flexibility and water resistance.
* Vinyl groups act as crosslinking points, resulting in a denser and more uniform network structure.

Modification Technologies:
* Introducing fluorinated surface additives to improve hydrophobicity (hydrophobic angle up to 120°).
* Using fumed silica for reinforcement to improve tear strength.
* Using platinum catalysts + hydrogen-containing silicone oil crosslinking agents.

Future Development Directions:
* Developing radiation-resistant rubber compounds with higher phenyl content.
* Optimizing filler treatment technology to improve radiation stability.
* Developing multifunctional composite radiation-resistant materials.