Silicone elastomers are compounded using reactive, straight-chained molecules with a cross-linking agent and reinforcement materials to enhance their mechanical properties, such as elasticity, absorption, and tear strength.
Chemical structure
Silicone elastomers are produced by combining linear polymers, reinforcing agents, a crosslinker, and a catalyst. The viscosity and type of the base straight-chain molecule combined with the processing temperature, determine the type of elastomer formed: Heat Cured Rubber (HCR), Liquid Silicone Rubber (LSR), or Room Temperature Vulcanization (RTV). These elastomers can be reinforced by incorporating mineral fillers like alumina, silicone resins, silica, calcium carbonate, …
Radical, condensation, or additional crosslinking reactions depend on the selected technology to meet specific processing requirements. To achieve desired characteristics (such as color, rheology, pot life) or performance standards (electrical insulation or conduction, heat transfer, fire retardancy, chemical adhesion, mold release), a wide range of additives can be included in the final composition of the elastomer.
Advantages Of Silicone Elastomer
Key benefits of silicone elastomers include:
Extreme Temperature & Excellent Environmental Resistance: Silicone elastomers are used in high-performance applications, particularly in demanding environments where other polymeric materials would fail. Components fabricated from silicone elastomer rubber offer exceptional durability and reliability, even when subjected to extreme temperature ranges (-50 °C to 250 °C) or harsh outdoor conditions (humidity, UV radiation, ozone exposure). Their excellent dielectric properties and thermal resistance make them particularly suitable for insulating and safeguarding electronic equipment, including the protection of high-voltage lines.
Quality: Silicone elastomers are well-suited for high-performance applications where exceptional purity is required. They adapt to diverse manufacturing challenges across various industries, including mold-making, automotive, electronics, household item manufacturing, and more. Additionally, silicone elastomers can be manufactured to be food-grade compliant, expanding their potential for specialized uses..
Versatility: Silicone elastomers are highly customizable, allowing for easy and economical adaptation to changing procedural and performance requirements. This versatility makes silicone elastomers a preferred choice for dynamic organizations that drive innovation in manufacturing and testing.
Performance: Specific properties of silicone elastomers include resistance to hot and cold temperatures maintaining a low compression set even in extreme heat while remaining flexible in environments as cold as -40˚C. Furthermore, silicone elastomers offer additional qualities such as low flammability, high dielectric strength, sterilizability, durability, and excellent overall mechanical properties, enhancing their suitability for a wide range of applications. Silicone elastomers are also innocuous for the human body making them ideal for medical applications (skin contact, medical devices, long-term implants, etc.).
See more: Medical Grade Liquid Silicone Rubber
Disadvantages Of Silicone Elastomer
Cost: Silicone elastomers are considered a premium product, which typically come with a higher price tag compared to rubber and other materials. However, in many cases, this higher initial cost can be offset by improvements in quality control and uptime, as they tend to have fewer issues with contamination. Evaluating whether the cost is justifiable for your specific application requires a careful examination of your budget and production requirements.
Feel: Untreated silicone elastomers can have a slightly sticky feel when touched. This gives them a rougher appearance and may cause dust and other particles to adhere to the surface. If this is a concern for your application, specific treatments can be applied to minimize or eliminate this issue.
Compatibility: One significant disadvantage of silicone elastomers is their chemical compatibility. While they are highly versatile, there are certain environments and applications where they may perform poorly or have negative reactions. For example, silicone elastomers should not be submerged in alcohol or gasoline, and exposure to latex, sulfur, and certain other materials can inhibit their curing process. It is crucial to carefully assess the chemical environment present in your processes before determining if silicone elastomers are suitable for your needs.
In conclusion, elastomeric silicone, like any other material, comes with its own set of advantages and disadvantages. While it offers great versatility, it may not be suitable for every application. To explore the potential uses of silicone elastomers further, we recommend reaching out to the A1 Silicones directly for more information.