Views: 262 Author: Jasmine Publish Time: 2023-07-17 Origin: Site
Learn about the many forms of this versatile material and their applications.
Since its creation in the 1930s, silicone rubber has evolved into hundreds of material grades and forms that may be used in applications that were not even imagined when it was initially produced. Silicone product growth is expected to continue because of its exceptional temperature resistance, flexibility, and chemical inert nature. Silicones have proliferated in nearly every industrial, consumer, and medical market area.
This article will go through the four major forms of silicone rubber. We will also discuss the other major silicone rubber varieties and their applications.
"Room-temperature vulcanizing" (RTV) silicones are silicones that do not require heat to cure to their ultimate form. RTV is classified into two types: one-component formulations (RTV-1) and two-component formulations (RTV-2).
RTV-1 is delivered ready to use. Once sprayed, a silicone stabilizing agent soon begins to react with moisture in the air, curing the exterior. Cross-linking agents of several sorts are utilized. While setting, some emit trace quantities of acetic acid, amines, or alcohols, while others are odorless. RTV-1 silicones are recognized for their simplicity of usage, adhesion, and high-temperature stability. Sealants, bonding glues, and coatings have common uses. The picture below depicts RTV-1 being used as a sealant.
RTV-2 comes in two parts that must be blended immediately before usage. Once blended, it cures quicker than RTV-1. RTV-2 is available in a greater range of goods and has superior mechanical qualities throughout a wide temperature range. Condensation-cured RTV-2 is less costly than platinum-cured RTV-2. Platinum-cured silicone emits no byproducts, which is beneficial in some applications. RTV-2 has a wide range of uses, including 3D printing, coatings, and molds.
The term "liquid silicone" primarily refers to the initial state of the incoming stock utilized to make silicone goods. Previously, silicone grades were delivered in a semi-solid, gummy condition that required compression molding. Liquid silicone rubber (LSR) is a fluid, two-part platinum-cured raw material. This enables fine detail capture in injection-molded components or adhering to any surface shape as a coating. LSR's platinum-curing cross-linking method produces no byproducts during curing, making it suitable for food and medical-grade applications.
Fluorosilicone is a polysiloxane (silicone) molecular variant. It shares the same fundamental silicon-oxygen chain. Trifluoropropyl groups replace some of the methyl (CH3) groups found on the typical silicone molecule. This modification improves fluorosilicone's resistance to a variety of challenging service conditions, including gasoline and oil, mineral spirits, toluene, and other organic solvents. Fluorosilicone provides significant chemical resistance improvements while retaining almost the same mechanical qualities as traditional silicone. Fluorosilicone does not function as well as silicone in hot air, and it is significantly more costly. It is most suited to aerospace and automotive applications, where exposure to gasoline and other chemicals is more likely.
Silicone rubber with a high consistency is often known as "solid silicone" or "gum stock." It is made up of polysiloxane chains with a high molecular weight. To improve particular qualities like hardness and heat resistance, HCR can incorporate a variety of fillers. HCR can be treated using either peroxide or platinum catalyst compositions. During curing, the latter produces no chemical byproducts. For further processing, the material is offered in bulk forms such as bars, tubes, and cylinders. HCR is an excellent material for long-term implanted medical devices, automobile engine components, and a wide range of consumer goods.