Materials for Spacecraft Sealing Phenyl silicone rubber, as a special polymer material, plays an irreplaceable and important role in the field of spacecraft sealing components. Based on search results, the following are detailed technical requirements and applications of phenyl silicone rubber materials for spacecraft sealing:

I. Core Performance Requirements Spacecraft sealing components impose extremely stringent performance requirements on phenyl silicone rubber materials:

Space Environment Adaptability: * Excellent vacuum resistance to adapt to the extreme low-pressure environment of space.
* Excellent resistance to ultraviolet radiation and charged particle irradiation, allowing for long-term exposure to space radiation.
* Good resistance to space atomic oxygen to prevent material degradation caused by atomic oxygen erosion.
* Excellent resistance to the combined effects of various space environmental factors.

Extreme Temperature Performance:
* Maintain good flexibility at extremely low temperatures (below -40℃) to prevent material hardening and cracking.
* Excellent resistance to thermal cycling to withstand drastic temperature changes in the space environment.
* High-Temperature Stability to withstand instantaneous high temperatures during launch.

Mechanical and Chemical Properties:
* High tear strength (up to 49 kN/m) and appropriate tensile strength (10.41 kN/m). (MPa) Excellent ozone resistance, preventing ozone-induced material aging. Non-toxic and non-polluting properties, ensuring no adverse effects on astronaut safety and instrument operation. Good resistance to radiation degradation, maintaining mechanical properties even under radiation conditions.

Processing performance: Suitable vulcanization characteristics (t90 time controllable). Vulcanization efficiency can be optimized by adjusting the vinyl content (0.03%-0.25%). The amount of hydrogen-containing silicone oil added (e.g., 1.5 phr) can significantly improve tear strength.

II. Material Standards and Formulation Characteristics
National Standards and Industry Level: The performance of the phenyl silicone rubber material developed by Aiyota Silicone Oil Co., Ltd. has reached the level of similar foreign products. Performance breakthroughs have been achieved through controlling key technologies such as the molecular weight and distribution, and sequence structure of phenyl silicone rubber.

Key Formulation Parameters: Vinyl content: 0.04%-0.08% is the preferred range. Hydrogen-containing silicone oil addition: 1.5 phr PHR achieves optimal overall performance. Selection and dosage optimization of vulcanizing agent DBPMH. Nano-processing of silica filler (20-30 nm particle size).

Special modification technologies: Surface modification technology for fumed silica, increasing the upper temperature resistance by 15%; Vinyl end-capping technology, creating active cross-linking points at the ends of raw rubber molecular chains; Segmented temperature vulcanization method (two reaction steps: 160℃ and 200℃).

III. Typical Application Cases
China Space Station Project: Used in the sealing components of the Tianhe core module, serving as the "lifeline" material of the space station; meeting the long-term on-orbit sealing requirements of manned spacecraft sealing components.

Launch Vehicle System: Key sealing components of the Long March 5B Y2 launch vehicle; withstands vibration and thermal shock during launch.
Other aerospace applications: Satellite space sealing system; Spacecraft environmental control and life support system sealing; Spacecraft thermal insulation materials; Nuclear power cable protective layer.

IV. Technological Development Trends
Continuous Performance Improvement:
Development of low-temperature resistant rubber compounds with 7% phenyl content (maintaining elasticity even at -40℃)
Introduction of fluorinated surface additives, achieving a hydrophobic angle of 120°
Design of a gradient hardness structure (Shore A40-70)

Production Process Optimization:
Closed-loop mixing system reduces mixing time from 40 minutes to 12 minutes
Energy consumption reduced by 35%, batch performance variation less than 2%
PID temperature control system ensures heat treatment temperature fluctuations do not exceed ±1℃

Testing and Verification Requirements:
Passing 200 cycles of thermal shock (-40℃~120℃)
Corona resistance life exceeding 100,000 hours
Space comprehensive environmental simulation test

The application of phenyl silicone rubber materials in the aerospace field fully demonstrates the irreplaceable nature of special polymer materials in extreme environments. With the rapid development of China's aerospace industry, the demand and technical requirements for such high-performance materials will continue to increase.