What is silicone?
Technically, silicone is considered part of the rubber family. But, if you define plastics widely, as we do, silicone is something of a Hybrid between a synthetic rubber and a synthetic plastic polymer. Silicone can be used to make malleable rubber-like items, hard resins, and spreadable fluids.
We treat silicone as a plastic like any other, given that it has many plastic-like properties: flexibility, malleability, clarity, temperature resistance, water resistance.
Like plastic, it can be shaped or formed and softened or hardened into practically anything. But it is a unique material because it is much more temperature resistant and durable than most plastics and has a low reactivity with chemicals. And while water resistant, it is also highly gas permeable, making it useful for medical or industrial applications where air flow is required. It's also easy-to-clean, non-stick, and non-staining, making it popular for cookware, bakeware, kitchen utensils and several other day to day utility products.
Brief description of Silicone?
"First of all, silicone is no more "natural" than fossil-based plastic. It is a man-made polymer, but instead of a carbon backbone like plastic, it has a backbone of silicon and oxygen. (Note: Using two different words here: silicone is the polymer and silicon, spelled without the "e" on the end, is an ingredient in silicone.) Silicon is an element found in silica, i.e., sand, one of the most common materials on earth. However, to make silicone, silicon is extracted from silica (it rarely exists by itself in nature) and passed through hydrocarbons to create a new polymer with an inorganic silicon-oxygen backbone and carbon-based side groups. What that means is that while the silicon might come from a relatively benign and plentiful resource like sand, the hydrocarbons in silicone come from fossil sources like petroleum and natural gas. So silicone is a kind of hybrid material."
Thus, while most plastics have a polymer backbone of hydrogen and carbon where as silicones have a backbone made of silicon and oxygen, and hydrocarbon side groups - all of which gives them plastic-like characteristics for long life.
Silicone is often used for baby nipples, cookware, bakeware, utensils, and toys. Silicones are also used for insulation, sealants, adhesives, lubricants, gaskets, filters, medical applications (e.g., tubing), casing for electrical components.
Toxicity: Is Silicone Safe?
Many experts and authorities consider silicone completely safe for food use. "There are no known health hazards associated with use of silicone cookware. Silicone rubber does not react with food or beverages, or produce any hazardous fumes."
Properties of Silicone.
Silicones exhibit many useful characteristics,
- Low thermal conductivity
- Low chemical reactivity
- Low toxicity
- Thermal stability (constancy of properties over a wide temperature range of −100 to 250 °C).
- The ability to repel water and form watertight seals.
- Does not stick to many substrates, but adheres very well to others, e.g. glass.
- Does not support microbiological growth.
- Resistance to oxygen, ozone, and ultraviolet (UV) light. This property has led to widespread use of silicones in the construction industry (e.g. coatings, fire protection, glazing seals) and the automotive industry (external gaskets, external trim).
- Electrical insulation properties. Because silicone can be formulated to be electrically insulative or conductive, it is suitable for a wide range of electrical applications.
- High gas permeability: at room temperature (25 °C), the permeability of silicone rubber for such gases as oxygen is approximately 400 times that of butyl rubber, making silicone useful for medical applications in which increased aeration is desired. Consequently, silicone rubbers cannot be used where gas-tight seals are necessary.
Why Silicone ? for making a variety of utility products.
- Withstands high & low temperatures far better than organic rubber
- Good thermal stability
- Repels water & forms tight seals
- Excellent electrical insulation, no decline in insulation performance even when immersed in water, making it an ideal insulating material
- Flexible at low temperatures, stiffens up at higher temperatures
- Under ordinary pressure, contact with steam typically causes little or no deterioration
- Flame retardant, will not ignite easily. Some products received UL94 V-0 certification according to the UL94 (USA) standards for flammability classification.
- Unlike most organic elastomer's such as EPDM and neoprene, the compression set of silicone rubber is consistent over a wide range of temperatures from -60° to +250°C. The selection of a proper curing agent and post-curing is particularly recommended when using silicone material to make molded products that require a low compression set.
- Customizable for specific applications by adjusting the compound recipe by selecting the proper curing agent and/or post-curing the compound to improve resistance to flames, steam & hot water (over 150C) Low chemical reactivity.
Scope of Silicone Products in India.
With these characteristics like extended lifetime and a wide temperature operating range, low toxicity, low flammability, low smoke density, inertness to chemicals & solvents, oil & fuel resistance, and high productivity are some key attributes assisting industry penetration a strong R&D focus for application development is creating the growth opportunities in the India Market.