Fluorosilicone rubber is a linear polymer with Si—O—Si as the main chain and fluoroalkyl or fluoroaryl groups as side chains. Due to the excellent flexibility of the molecular chain, it not only has the good heat resistance, cold resistance, ozone resistance and other properties of silicone rubber, but also contains fluorine atoms in the side chain, and has the resistance to hydrocarbon solvents and hydrocarbon solvents of fluorine-containing rubber materials. It has a series of excellent properties such as oil resistance, chemical resistance, high and low temperature resistance, etc., so it is currently widely used in aerospace, automobiles, ships, electronic communications, electrical appliances, precision machinery, petrochemicals, medical and health and other fields.


Fluorosilicone rubber is a relatively expensive special material, and its shelf life has attracted much attention. Relevant literature points out that under recommended storage conditions, the shelf life of fluorosilicone rubber is 10 years.
What are the recommended storage conditions?
1. Temperature: 5℃ to 25℃ is the ideal storage temperature.
2. Humidity: Relative humidity is lower than 70%, avoid being too humid and too dry.
3. Lighting: Avoid sunlight and strong artificial light sources containing ultraviolet rays.
4. Radiation: Avoid ionizing radiation.

5. Oxygen and Ozone: Avoid exposure to circulating air.

6. Deformation: Place it in a free state as much as possible to avoid stretching, compression or other deformation.

In addition, no contact with solvents, grease, metal, etc. is allowed.

The 53rd Research Institute of China Ordnance Industry Group conducted a 2-year storage experiment in the warehouse.

 

The experiment was carried out in five regions with a relatively typical climate across the country, namely:

Wanning City, Hainan - hot and humid marine climate, hot and humid.

Mohe County, Heilongjiang Province - has a cold inland climate, long winters, and the number of -40°C temperature days can reach more than 2 months per year.

Dunhuang City, Gansu Province - has a hot and dry desert climate, with high temperatures, large temperature differences between day and night, low relative humidity, strong solar radiation, scarce precipitation, and frequent sandstorms.

Xishuangbanna Prefecture, Yunnan Province - subtropical rainforest climate, long summer without winter, spring and autumn are connected, rain and heat are in the same season, rainfall is abundant, and rainfall intensity is high.

Jinan City, Shandong Province - Temperate climate, mild climate, no hot and humid months.

In the natural state, that is, without any external force, the tensile strength, elongation at break, resilience, Shore A hardness, and 100% elongation stress of fluorosilicone rubber samples stocked in different regions increase with aging time. , the changes are not obvious, but due to differences in environmental factors such as moisture and temperature in various regions, there are certain fluctuations in related properties, such as elongation at break, resilience and 100% elongation stress, etc. But overall, the fluctuations in various properties of fluorosilicone rubber in the five regions are not very large, and there is no obvious attenuation or difference.

When the material compression rate is 25%, the compression permanent deformation retention rate of fluorosilicone rubber in each region decreases significantly with aging time, and the magnitude of the decrease is different in each region. Compared with the mechanics of the material in the natural state The performance shows certain differences, which can better reflect the differences in material performance and service life of fluorosilicone rubber in different regions due to differences in environmental factors.

By establishing an inference model, constructing a life equation and verifying the regression effect, the author analyzed and pointed out: the higher the annual average temperature, the stronger the movement ability of the polymer chain, and the more structural units that can move, and then the material's performance change rate also increases. The larger the value, the faster the performance of the material changes when other conditions are the same, which manifests as the shorter the storage life of fluorosilicone rubber.


Low pressure variable fluorosilicone compound