Silicone materials, or organic silicon compounds, are a class of compounds with unique physical and chemical properties. They contain Si-C bonds and at least one organic group is directly connected to the silicon atom. The following are the main physical and chemical properties of silicone materials:
I. Physical properties
Thermal stability:
Silicon products have a silicon-oxygen (Si-O) bond as the main chain structure. The bond energy of this bond is relatively high (121 kcal/g molecule, compared with 82.6 kcal/g molecule of C-C bond), which makes silicone materials stable at high temperatures and not easy to decompose or break. Therefore, silicone materials have excellent high temperature resistance and low temperature resistance, and can be used in a wide temperature range.
Surface tension:
Silicon materials have low surface tension, which makes them have good film-forming ability and wetting properties. This low surface tension is also one of the main reasons why silicone materials have been used in many aspects (such as hydrophobic, defoaming, anti-sticking, etc.).
Viscosity and fluidity:
The main chain of silicone materials is flexible and the intermolecular force is relatively weak, so their viscosity is low and their fluidity is good. This property makes silicone materials more flexible in processing and application.
Gas permeability:
Silicone materials have high gas permeability, which affects their sealing performance to a certain extent, but is beneficial in certain specific applications (such as gas separation membranes).
2. Chemical properties
Weather resistance:
Since there are no double bonds in the main chain of silicone materials, they are not easily decomposed by ultraviolet light and ozone, and have excellent weather resistance. This allows silicone materials to maintain stable performance for a long time in outdoor environments.
Corrosion resistance:
Silicone materials have good corrosion resistance to a variety of chemicals (such as acids, alkalis, salts, etc.), which makes them widely used in chemical, textile, food and other industries.
Electrical insulation:
Silicone materials have excellent electrical insulation properties, and their dielectric loss, voltage resistance, arc resistance, corona resistance and other properties are excellent. This makes silicone materials widely used in the electrical and electronic industries, such as the manufacture of wires and cables, electronic components, etc.
Biological inertness:
Silicone materials are non-toxic, odorless and physiologically inert to human tissue, which means that they will not react with human tissue or cause discomfort. Therefore, silicone materials are widely used in the medical industry, such as in the manufacture of artificial joints, pacemakers and other medical devices.
