Silicone

Silicone Material Superiority

Silicone rubber is a very special elastomer mixed with a polysiloxane polymer, which is shared by organic and inorganic groups, and inorganic silica. This is what we call a silicone rubber. Silicone RUBBER has very good properties not found in other organic rubbers and is used in a wide variety of industries such as medical, kitchen, construction, shipbuilding, aviation, electricity, electronics, communication, machinery, automotive, painting, Silicone rubbers have superior resilience, weatherability, ultraviolet rays and heat resistance among the existing rubber used.

 


 

Definition of Silicone

1. Terminology: Silicon and Silicone

Silicon

an element represented by Si. The material is a dark gray metal phase

(Ex. silicon wiper for semiconductors)

Silicone

It means a polymer in which the organic group-containing silicone (organodilicon) and oxygen are chemically bonded to each other. It is a unique chemical material having both organic and inorganic properties. It is applied in various forms, (A polymer formed by linking an organic group-bonded silicone with a siloxane bond [Si-O-Si])

 

2. Origin

Since the chemical formula R2SiO of the SILICONE synthesized in the late 19C laboratory was similar to R2C0 of the ketone, it was called Silco-Ketone (silicone ketone), and was reduced to SILICONE

 


 

Characteristics of Silicone

Heat resistance

The C-C bonding energy, which is the main axis of organic synthetic rubber, is 83 kcal / mol, while the Si-0 bonding energy is 108 kcal / mol. Due to the difference in bonding energy, excellent heat resistance of the silicone rubber is exhibited. Silicone rubber has a heat-resistant temperature range of 150 ~ 25013, and can be used up to 350 ℃ when used intermittently for a short time.

Continuous use time of silicone rubber by temperature Temperature (℃) Continuous use time
150 15,000
200 7,500
260 2,000
316 100
370 1/4-2/1
Cold resistance

The low temperature resistance of silicone rubber is the best among all kinds of rubber.

 

The saturation point of the general organic rubber is -20 ° C to -4 ° C compared with -60 ° C to -70 ° C of the silicone rubber. Therefore, the silicone rubber maintains elasticity almost unchanged even at a low temperature at which the organic rubber breaks, Rubber (PVMQ) can be used at ultra-low temperatures up to -100 ° C

Weatherability Unlike other organic rubbers, oxygen in the atmosphere in the molecular structure. Ozone, ultraviolet rays, and so on, it has excellent weatherability because there is no double bond that causes cracks.
Compression Permanent String Ratio Compressive permanent shrinkage of general organic rubber increases remarkably with temperature, whereas elasticity and restoring force are maintained in a wide temperature range from -10 ℃ to 250 ℃. Therefore, even if compressive deformation is required under extreme conditions Performance
Oil resistance Silicone rubber is excellent in oil resistance at high temperatures where general organic rubber except fluorine rubber can not be used.

Chemical resistance

Heat-water-resistantr

Excellent chemical resistance. It is not infringed by polar organic compounds such as alkali. However, strong acid or strong alkali may be infringed. Therefore, when it is used in connection with these, it must be decided whether or not to use after testing. Silicone rubber hardly changes in properties even when it is settled in water for a long time or comes into contact with steam. If the steam pressure is 2 kgf / ㎤, some decomposition may occur at the contact surface, but it can be improved by selecting the appropriate hardening agent and changing the hardening condition.
Electrical characteristic

Silicone rubber has a unique chemical structure and low carbon content in the molecule. It does not use carbon black, which is used as filler in general organic rubber. Therefore, it has excellent resistance to arc (ARC) and corona discharge lamps under high voltage regardless of temperature and frequency It can be used as an insulator even under harsh conditions because it is widely used as an insulating material and leaves silica as an insulating material even when it is burned.

On the other hand, there are conductive silicone rubbers that have a resistance value of 5 Ω-cm or less by mixing conductive additives such as carbon.

ductility Silicone rubber does not burn easily because its molecular structure contains less hydrocarbon than conventional organic rubber. It does not contain halogen element and does not generate toxic gas when burned. In addition, when a separate flame retardant is blended, it becomes a flame retardant or a self-extinguishing silicone rubber that conforms to the UL standard.

Etc

In addition to the above characteristics, silicone rubber has many characteristics that ordinary organic rubber does not have.

It has higher thermal conductivity than conventional organic rubber and is used as insulation buffer for insulation coating and heat dissipation electrical appliances.

Its permeability to gases is 30 to 40 times higher than that of organic rubber, and is used for special applications such as air permeation membranes for air curing and water separators.

Excellent durability against radiation.

Excellent transparency and coloring.

It is chemically inert and does not corrode other materials. Excellent durability.

 

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