Adhesive silicone is a versatile sealant that can be used for anything from household tasks to bonding components in outer space. It can withstand extreme temperatures and resist aging, making it ideal for many different applications.
When using silicone adhesives it is important to consider substrate wettability. This is the ability of a substrate to accept a liquid adhesive and can be determined by its surface energy value.
Easy to Apply
Adhesive silicone can be used on a variety of surfaces. Its non-reactive, chemically stable properties make it a good choice for bonding different materials such as metals and glass. It also resists extreme temperatures, making it a good choice for high-performance and long-lasting applications.
Unlike other adhesives, which may have negative effects on your health, adhesive silicone is safe to use and does not release harmful fumes. It is also very easy to apply, requiring no significant preparation. It is a good idea to clean the surface of the item you are applying the silicone to, though, as it could have a residue that will prevent the silicone from adhering properly.
Before applying the adhesive, sand it down with low-grit sandpaper or use a fine grit steel wool to remove any corrosion. After this, wipe down the area with a lint-free cloth. You should then spray the surface with a solvent-based Activator/Accelerator or our Poly Prep to promote adhesion.
Once the surface is ready, simply apply a thick coat of the product to the desired area. Then, wait for it to set before attaching anything else. Depending on the type of silicone you have chosen, this will take a different amount of time. Some are fast setting, while others will require more time to cure fully. For best results, you should use an RTV silicone that is formulated for high temperature applications.
Despite their flexible nature, silicone adhesives are extremely strong and durable. This makes them ideal for bonding to difficult-to-bond-to surfaces, especially in demanding applications that require the adhesive to maintain its strength adhesive silicone under high temperatures, water submersion, vibrations and other environmental stresses. These features make silicone adhesives suitable for a wide range of industries, including electronics, automotive and life science. For example, silicone-based adhesives can be used for the assembly of medical catheters, and they are often applied to the surface of printed circuit boards to provide electrical insulation.
To achieve their robust adhesion, silicone adhesives rely on both physisorption and chemisorption mechanisms of adhesion. The silanol groups on the PDMS backbone react with surface chemical groups found on many common substrates, forming Si-O-Si bonds. This mechanism allows the silicone to adhere to the substrate without being pretreated with a primer.
However, some substrates are difficult to stick to with a single silicone adhesive, which is why some formulations of silicone adhesive include a primer to facilitate this reaction. These primers are typically a mixture of organosilanes, which can react with the silanol groups on the PDMS to form Si-O-Si bonds with the substrate.
Another way to improve the adhesion of a silicone adhesive is by using a pressure sensitive silicone (PSA). These are synthetic elastomers that bond when they are exposed to pressure. These adhesives are perfect for use on surfaces that are not easy to stick to, such as release liners and low surface energy (LSE) materials. They also have excellent moisture resistance and can withstand exposure to chemicals and solvents.
When cured, silicone sealants can resist harsh weather elements such as rain, humidity and hot and cold temperatures. This durability makes it a great choice for outdoor projects, such as sealing gutters and vents or caulking windows and doors. Silicone can also be used to seal ductwork, appliances and other household items. Its weather resistance means it doesn’t shrink, crack or peel and can keep a secure seal in any climate.
There are many different types of silicone sealants available to meet specific applications. For example, sanitary sealants, like the GE GE012A, are ideal for use in bathrooms and kitchens because they can help prevent mold and mildew. Frame silicone sealants, such as the GE 31314, are durable and easy to apply to window or door frames. High-temperature silicones, like the Vitcas SS-30, are designed to handle high heat and are resistant to aging, shock and vibration.
Before you use a silicone sealant, make sure it’s the right one for your project. There are several things to consider when choosing a silicone adhesive, including its modulus and curing time. Low modulus sealants will need little force to stretch and are more elastic, while higher-modulus silicones are stiffer. Acid-cure silicones release vinegar-smelling acetic acid as they cure and can corrode metal, while neutral alkoxy silicones bond well to glass, plastics and aluminium but take longer to dry.
Silicone adhesives have low toxicity before, during and after curing. This makes them safer to work with than most other glues. Some silicone systems, like MasterSil 711, are non-corrosive and designed to be used with electronics while others, such as MasterSil 151Med, meet USP Class VI standards for medical applications and are biocompatible. Other silicone systems, like Kwik-Sil and Kwik-Cast, have platinum complex catalysts that are not sensitive to contamination from amines or animal tissue and offer rapid curing times of only a few minutes.
These properties make silicone adhesive tapes ideal adhesive silicone for use in medical and microfluidic applications as well as for bonding dissimilar materials. Additionally, silicone adhesives are inert and biocompatible which means they can be used around living tissue without causing irritation. They also have excellent moisture resistance and conformability. These characteristics, along with their chemical stability and adherence to LSE surfaces, make them ideal for use in research laboratories.
Pressure Sensitive Adhesives (PSA) are a type of silicone adhesive that creates a strong bond when exposed to pressure. PSAs can be applied to a variety of substrates and are often used in the automotive and aerospace industries. They are also commonly used for potting and sealing in electronic assemblies. They can be cured with UV light and are resistant to vibrations, shocks and temperature changes.