A common question that gets asked frequently is ‘does silicon melt.’ All the time, silicone stands out among a range of materials by virtue of its incredible heat resistance. While most plastics begin to melt at a high temperature, silicone retains its integrity and function. Till today, it is known that silicone has a wide temperature range tolerance varying from -60°C (-76°F) to 230°C (446°F). However, in regard to the melting point of silicone, even silicone engineers cannot give a definite answer. Some people doubt that the melting of silicone is virtually impossible. But it should be explained with further explorations.
This article will clarify the same doubt and cover the related silicone melting questions.
Top 4 Q&A Regarding Heating Silicone
(1) Does silicone melt in the heat?
Yes, the melting of silicone occurs in the right condition, with a much higher temperature than other polymers.
Silicone slowly loses its physical properties at extreme temperatures (above 200°C), becoming harder and more brittle. And this process will be further accelerated along with the increased heat temperature. Once the heat temperature reaches its unset auto-ignition point (around 450°C), the heat-resistant material will begin to smoke, expand in volume and emit volatile matters. Following this is the cracking and combustion of silicone. Ultimately it will crumble with powder.
However, the melting point and burning point of silicone are normally not achieved in the most industrial heating process. So it can be concluded that silicone can and does melt and burn, just at extremely intense temperatures and conditions.
(2) Why is silicone heat resistant?
Silicone has a high thermal due to its strong inter-atomic forces.
To more fully explore this matter, it is significant to figure out the formation of silicone. Unlike naturally occurring element silicon, all types of silicone are synthetic compounds made up of a long continuous chain of vertical and horizontal Si-O-Si bonds. The silicon-oxygen bond is much stronger than silicon-silicon bonds and not easily oxidized. Furthermore, the organic groups attached to silicon atoms can only be oxidized to form silica under high energies. That’s to say, the strong interaction of silicon and oxygen atoms makes the melting point of silicone so high.
(3) What are the effects of heating on silicone?
Generally speaking, silicone hardens when heated in air, and elongation decreases as it deteriorates. However, under sealed conditions, it will soften as it deteriorates, and its service life at high temperatures is shorter than in the air.
This softening stems from the degradation of the silicone polymer. Adjusting the silicone formulation to use a different curing agent can help prevent softening under high temperatures and sealed conditions.
(4) Is silicone toxic when heated?
If the question arises whether silicone becomes toxic after heating or not, the answer is no.
Silicone is non-toxic for the covalent bond of silicon-oxygen. In 1979, the FDA deemed silicone safe for cooking and everyday usage. Silicone products are microwave-safe, freezer-safe, and oven-safe. Despite common concerns, temperature changes will not cause food-grade silicone to leach into the environment.
Other Properties/Advantages of Silicone
Silicone is a commonly used substance, mainly due to its mechanical properties. Apart from high thermal, the following 3 strengths win a large advocate.
1. Stability Under UV Radiation
The high bonding energy of the silicon-to-oxygen backbone provides stability against breakdown by UV irradiation. Even high UV or harsh weather conditions, such as those found in coastal areas or deserts, have little or no effect on this resistance performance. Silicone only shows slight changes in mechanical and wet conditions, even after extended and accelerated weathering testing in climatic chambers.
Silicone polymers and molded components made with silicone elastomers exhibit low surface energy that does not allow water to spread over their surface, i.e., a hydrophobic or water-repellency property. These highly desirable characteristics can be evaluated by measuring the wetting angle of water droplets on the surface of silicone specimens.
3. Flame Retardancy
Silicone ignites only at very high temperature and thus exhibit good flame retardancy. Typically, silicone elastomers show either class V0 or HB under the relevant test criteria, making them particularly safe in operation. Moreover, if they do ignite, they burn without producing toxic gases, so they are well suited for applications subject to strict fire safety requirements, e.g., subways, tunnels, high-rise buildings, etc.
XHF, a Professional Provider of a High-quality All-round Services in Silicone Products
Silicone occupies an important place for its use because of its extraordinary physical property. The use of silicone appliances in daily life can be heard from the kitchen to the aerospace rockets. Being a big market, silicone products are definitely worth investing in.
This article presents XHF, a trustworthy silicone products supplier to you. The company has 18 years of rich industry experience and provides one-stop, customized services to its customers with its quality R & D team. Additionally, the company is equipped with advanced production lines and dust-free workplaces to guarantee product quality and safeguard customers’ rights.
In brief, never hesitate to XHF when selecting a silicone products supplier.