Why Doesn’t Silicone Melt Or Burn?

Silicones, also known as polysiloxanes, are polymers that include any synthetic compound made up of repeating units of siloxane, which is a chain of alternating silicon atoms and oxygen atoms, combined with carbon, hydrogen, and sometimes other elements. They are typically heat-resistant and either liquid or rubber-like, and are used in sealants, adhesives, lubricants, medicine, cooking utensils, and thermal and electrical insulation. Some common forms include silicone oil, silicone grease, silicone rubber, silicone resin, and silicone caulk.

Silicone rubber offers good resistance to extreme temperatures, being able to operate normally from −100 to 350 °C (−148 to 662 °F). Some properties such as elongation, creep, cyclic flexing, tear strength, compression set, dielectric strength (at high voltage), thermal conductivity, fire resistance and in some cases tensile strength can be—at extreme temperatures—far superior to organic rubbers in general, although a few of these properties are still lower than for some specialty materials. Silicone rubber is a material of choice in the industry when retention of initial shape and mechanical strength are desired under heavy thermal stress or sub-zero temperatures.

Organic rubber has a carbon-to-carbon backbone which can leave it susceptible to ozone, UV, heat and other aging factors that silicone rubber can withstand well. This makes silicone rubber one of the elastomers of choice in many extreme environments.

There are many special grades and forms of silicone rubber, including steam resistant, metal detectable, high tear strength, extremely high temperature, extremely low temperature, electrically conductive, chemical/oil/acid/gas resistant, low smoke emitting, and flame-retardant. A variety of fillers can be used in silicone rubber, although most are non-reinforcing and lower the tensile strength.

Silicone rubber is available in a range of hardness levels, expressed as Shore A or IRHD between 10 and 100, the higher number being the harder compound. It is also available in virtually any color and can be color matched.

So does silicone melt or burn?

1.Does Silicone melt?

While most plastics will begin to melt at high temperatures, silicone does not have a melting point and remains solid until combustion occurs. 

Silicone doesn’t melt at quite high temperatures, but it does melt. so let’s explain by taking a second, deeper look at the naturally occurring chemical element silicon from which silicone rubber is made.

With the high temperature, When silicone decomposes, it becomes silicon. Then it will melt in 1414°C

The first thing you will notice is that silicone doesn’t melt due to temperature alone! Special grades are available to further increase silicones already naturally high resistance to heat such as our silicone grade which can be used intermittently at temperatures up to 350°C

The applicable temperature range of silicone products, the temperature resistance range of conventional silica gel is -40℃~230℃,

After special treatment, the temperature resistance range of certain types of silicone products can be expanded to -110℃~350℃.

In a low-temperature environment, the silicone product will become brittle if it exceeds the limit temperature that the silicone product can withstand.

The Silicon (no “e”) is a semimetallic element that melts at1414 °C, 2577°F.

In a high-temperature environment, if the temperature exceeds the limit temperature of 400℃, It will slowly lose its mechanical properties over time with extended high temperatures and then become brittle.  The silicone products are carbonized.

When the temperature reaches about 600°C, the silica gel products will re-sulfurize, and the products will be sticky, like clay. 

Without going into specifics silicone rubbers are known to remain stable at relatively high temperatures compared to most elastomer materials. Various silicone rubbers can be formulated, with additives, to withstand higher temperatures than the rubber alone can handle. Silicone (an adhesive compound of synthetic rubber) does not melt, Silicone rubbers do not melt but decompose when the temperature goes above certain limits. One of the decomposition products is silicon dioxide, also known as silicon.

2.Does Silicone burn?

Silicone is a non-flammable material in our lives. It is not easy to be burnt in an easy way. It would not burn if the temperature is 350℃. We always say silicone would not burn because the temperature of our lives would not be higher than 100℃. If the temperature is close to 430℃, the silicone would be burnt. But it would self-extinguish if it gets away from fire.

After the silicone burning. The burning area will become white. That is a way to check if your silicone products are real silicone made.

Conclusion

From the above information, we can see the silicone can be melted or burned in special conditions. 

In ZSR Group, We have rich experience in producing Custom silicone products with FDA or LFGB Approved standard products.  We have the FDA register list number is 3011147430.

Any Silicone products or Silicone projects need technical support, contact us.

You also can customize Silicone products at ZSR Group.