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Silicone rubber sheets are made of silicon bonded with carbon, hydrogen, and oxygen and is then vulcanized to create a solid silicone elastomer with a unique silicon-oxygen bonded saturated backbone structure. Its unique silicon-oxygen polymer backbone offers superior resistance to extreme high and low temperatures while also creating an environmentally resistant material. Silicone material is an elastomer with excellent flexibility at low temperatures and outstanding resistance to UV radiation and ozone. These properties make silicone weatherstripping a popular product seen in car and home window seals. Furthermore, silicone parts for industrial use will offer long life in abrasive applications whether it be outdoors or in high temperature applications.
How Do You Make Silicone Rubber Sheets?
You can make silicone rubber sheets by vulcanizing the uncured liquid silicone material made up of silicon, carbon, hydrogen, and oxygen to create a solid material. Vulcanization “is a chemical process in which the rubber is heated with sulphur, accelerator, and activator at 140-160C” to create a solid sheet (sciencedirect.com). Silicone rubber sheets are elastomers that are composed of “silicone – itself a polymer – containing silicon together with carbon, hydrogen, and oxygen” that have been vulcanized into a solid material (Wikipedia.org). The element “silica” is found in almost every type of sand around the world and is used in the production of a silicone elastomer. Firstly, the silica “is heated with carbon in an industrial furnace to extract the silicon, which is them passed through hydrocarbons to create a new polymer with an inorganic silicon-oxygen backbone and carbon-based side groups” (earthhero.com). Silicone material is considered an “inorganic” polymer when compared to other variations due to its unique polymer backbone structure. For instance, “silicones differ from most industrial polymers in that the chains of linked atoms that make up the backbones of their molecules do not contain carbon, the characteristic element of organic compounds. The lack of carbon in the polymer backbones makes polysiloxanes into unusual ‘inorganic’ polymers—though in most members of the class two organic groups, usually vinyl (CH2), methyl (CH3), or phenyl (C6H5), are attached to each silicon atom” (Britannica.com). Instead, the backbone structure of silicone rubber sheets is made up of a silicon-oxygen chain which gives the material its unique resistance properties. Compared to organic rubber, silicone is an extremely resilient material that has excellent heat resistance, chemical stability, electrical insulation, abrasion resistance, and weatherability as well as ozone resistance due to its Si-O bond (omnexus.specialchem.com). Silicone rubber sheets are made through the vulcanization of silicon, carbon, hydrogen, and oxygen that creates a solid rubber material that is highly resistant against outdoor damaging factors as well as abrasive temperatures and chemicals.
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(a) Is Silicone a Rubber or Plastic?
Silicone is considered a rubber rather than a plastic due to its flexibility and better resistance against breaking or tearing when stretched. Silicone, or siloxanes, “are something of a hybrid between synthetic rubbers and synthetic plastic elastomers” (mindbodygreen.com). Silicone rubber sheets are valued for being an eco-friendlier option over plastic while also retaining better resistance properties to abrasive temperatures, chemicals, and damaging environmental factors. It is important to understand that silicone rubber sheets are not 100% environmentally friendly materials, but they are eco-friendlier than plastics. This is true because silicon, one of the main chemical elements that make up silicone, derives from silica which is readily available in almost all types of sand. The chemical “silicon” is a for of silica found in sand that is used in the production of silicone rubber sheets; however, the silicon first needs to be extracted from the silica through a heating process that heats the material with carbon. Furthermore, silicone and plastics have contrasting resistance properties. For instance, “Unlike plastics, silicone has a high resistance to temperature, low reactivity with chemicals, doesn’t support microbiological growth, repels water, and is resistant to ultraviolet (UV light)” (earthhero.com). Plastics, on the other hand, are often made of non-renewable crude oil that is then altered to form a unique carbon. The properties of plastic are much weaker than those of silicone material. Plastic retains properties, such as “low density, low electrical conductivity, transparency, and toughness”, but it is not resistant to extreme temperatures or environmental factors making it less versatile than silicone material. Silicone is able to stand up well against degradation caused by UV rays and ozone which often causes materials to fade in color or crack. Due to these outstanding environmental properties, silicone weatherstripping is commonly seen in outdoor settings or applications, such as vehicle or residential window seals. Despite the strong physical properties of plastic, silicone rubber sheets are a far superior material when it comes to elasticity, resilience, and resistance to outdoor damaging factors.
(b) Is Silicone and Rubber the Same Thing?
Although silicone and rubber are both elastomers, the difference in the way they are structured gives them each different resistance properties and lifespans. As polymers, both elastomers retain a unique saturated backbone structure that gives them each their own set of resistance properties. For example, “One of the key differences between silicone and rubber is that most of the rubbers contain polymer chains of carbon, however, silicone rubbers contain silicon in polymer chains instead of carbon” (westlab.com). Its silicon-based polymer backbone gives silicone parts excellent chemical and physical properties that give silicone material its indoor/outdoor versatility. Natural rubber variations are easily degraded by outdoor factors, including UV radiation, ozone, abrasive outdoor temperatures, and oxygen; however, “silicone is not affected by UV light or extremes in temperature” (westlab.com). The biggest different between rubber and a silicone elastomer can be seen through their common applications. A silicone elastomer can be used for human grade applications, such as medical equipment, food service/storage, and cosmetics; however, silicone rubber sheets may be used to create durable industrial silicone parts, such as seals and gaskets. Rubber, contrastingly, are generally used for more industrial applications and is not suitable for human grade applications. Case in point, “Rubber requires toxic additives to stabilize…In contrast with rubber, the process to create quality silicone does not require the addition of questionable stabilizing agents” (westlab.com). Overall, both rubber and silicone are durable elastomers; however, silicone parts tend to have longer lives and better resistance properties to damaging environmental factors.
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Is Silicone a Solid?
Silicone is a solid, but it can also be available in liquid form. Before it goes through the vulcanization process, silicone material, “is a highly adhesive gel or liquid” (Wikipedia.org). This uncured silicone material is then converted into a solid once it goes through the vulcanization, or curing, process. There are two ways of curing silicone. For example, “liquid silicone can be shaped into the shape of the final product and then vulcanized in a prolonged curing process or it can be injection molded…a manufacturing process for producing parts by injecting molten material into a mould, or mold” (Wikipedia.org). Solid silicone rubber sheets are completely different from liquid silicone material not just in form, but also in molecular weight and the length of their polymer chain. Solid silicone rubber sheets are extremely strong materials. For instance, “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…” (Wikipedia.org). Silicone’s wide operating temperature range is one of its most notable qualities and it allows the material to be used in cooking and food storage applications (for FDA approved silicone parts).
The molecular makeup of silicone rubber sheets gives them the ability to withstand abrasively high and low temperatures as well as resist deterioration caused by harsh UV rays and ozone. Unlike plastic, silicone material is far more resilient and better for the environment as the elemental building blocks of the elastomer can be abundantly found in sand whereas plastic is made out of non-renewable crude oil. Silicone elastomer is able to last longer than natural rubbers due to their inorganic silicon-oxygen bonded polymer backbone structure. This allows silicone parts to remain flexible and unfailing in both high and low temperatures whereas materials such as natural rubber or plastic may become brittle and crack. Overall, silicone rubber sheets are highly resilient materials that are made up of a unique silicon-oxygen bonded polymer backbone.
How Do You Make Silicone Rubber Sheets?
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