Are you struggling to choose between silicone and acrylic products? Both silicone and acrylic are used in construction, coatings, and medical applications. While they may appear similar in application, they are fundamentally distinct in their properties. This article will compare them in terms of adhesion, durability, and cost—hoping it helps you make a better choice.
What is silicone?
Silicone is a synthetic material made from elements like silicon, oxygen, hydrogen, and carbon. It is very soft and has properties such as being waterproof, resistant to aging, and able to withstand high and low temperatures, which makes it useful in many fields. Additionally, because it is safe,non-toxic and comfort skin contact, it is also widely used in the food and medical industries.
Advantages:
As a chemically inert material, silicone is resistant to reactions with other chemicals. It also possesses a combination of valuable properties, including resistance to oxidation and UV light, the ability to withstand extreme temperatures, and high tensile strength.
Disadvantages：
While silicone can turn yellow after prolonged use, this can be addressed by including anti-yellowing agents during processing. It also experiences a gradual loss of oil resistance over time. Moreover, the expensive nature of silicone is largely due to its complex and costly production methods.
What is acrylic？
Acrylic is a transparent thermoplastic polymer utilized as an engineering plastic, also widely known as poly(methyl methacrylate) (PMMA), acrylic glass, plexiglass. In its unmodified state, acrylic exhibits characteristics of brittleness, light weight, and transparency. Through chemical modification, its properties are enhanced to become strong, tough, and rigid. Frequently employed as a substitute for both glass and conventional plastics, acrylic is categorically classified as a type of plastic.
Advantages：
Acrylic offers diverse applications and long-lasting durability. It is cost-effective, lightweight, and exhibits high optical clarity. As a substitute for glass, it possesses softer and shatter resistance, eliminating the risk of sharp fragments and potential injuries. Additionally, it provides sound insulation properties.
Disadvantages:
Acrylic exhibits limited flexibility and relatively low heat resistance. Under high-temperature conditions, it may deform or become brittle. Prolonged exposure to ultraviolet (UV) radiation can cause acrylic to fade. Additionally, unless protected with a specialized scratch-resistant coating, surface scratches can compromise its optical clarity.
Differences between Silicone and Acrylic
Adhesion
Silicone sealant adheres effectively to various substrates including glass, metal and so on. It offers waterproof properties along with inherent hygienic qualities, being both antimicrobial and mold-resistant. These characteristics make it particularly suitable for moisture areas like your bathroom and kitchen. Furthermore, its permanent elasticity ensures optimal performance in expansion joints and moving gaps.
In contrast, acrylic sealants or coatings—available in both water-based and solvent-based formulations—demonstrate superior suitability for filling wall cracks, a application where silicone proves inadequate. While effective for gap sealing, acrylic products require dry conditions during application and service, as it lack moisture tolerance.
Modified acrylic enables you to achieve enhanced chemical resistance and superior adhesion to various substrates—even on oily or greasy surfaces—without experiencing significant deterioration. This formulation ensures reliable performance for your specific requirements.
Durability
Oil Resistance
Silicone exhibits poor oil resistance and may swell or deform upon prolonged contact with oils. It is particularly vulnerable to gasoline and other fuels, which can cause significant swelling or even degradation of the material.
If the silicone product you purchase is only briefly exposed to edible oils, it is generally acceptable. However, if you intend to use silicone in contact with industrial oils—such as gasoline, engine oil, or lubricants—prolonged exposure will cause the silicone to deteriorate, completely losing its elasticity and sealing function.
For standard acrylic, its oil resistance is also limited. While acrylic generally does not dissolve or corrode when exposed to oils, it may undergo certain physical changes. When in contact with solvent-based oils such as gasoline or engine oil, these substances can penetrate microscopic surface imperfections—intrinsic stress cracks formed during the acrylic manufacturing process. This penetration can lead to stress cracking or even fracture of the material. Following prolonged exposure, acrylic may experience gradual deterioration including loss of surface luster, haze formation, and slight softening.
However, acrylic rubber—a specialty synthetic rubber and an elastomer form—demonstrates exceptional resistance to both temperature and oil. Even when immersed in oil for extended periods, it effectively maintains its original shape, hardness, mechanical strength, and sealing performance. If you require materials with excellent oil resistance, acrylic rubber is exactly what you need.
UV Resistance
Silicone possesses a highly stable chemical structure that enables it to resist UV radiation effectively without strong absorption. While prolonged UV exposure may cause some surface-level changes, the inherent thermal and oxidative stability of silicone significantly minimizes its degradation.
Acrylic does not yellow or become brittle under prolonged UV exposure, unlike many other plastics—a key reason for its widespread outdoor applications. This durability stems from its inherent chemical structure, which allows transmission of ultraviolet radiation rather than absorption. During manufacturing, UV stabilizers or absorbers are often incorporated to further extend its service life.
Temperature Resistance
Silicone exhibits exceptional thermal stability across a wide temperature range (-60℃ to 250℃), maintaining both chemical integrity and flexibility under extreme conditions. Its tensile properties remain well-preserved throughout this spectrum. Even when exposed to temperatures exceeding 200℃, silicone neither softens nor melts, and unlike many plastics, it does not release toxic substances.
In contrast, acrylic demonstrates inferior temperature resistance compared to silicone. With a boiling point around 200℃ and a high coefficient of thermal expansion, acrylic undergoes dimensional changes rather than deformation when temperatures surpass 80℃—manifesting as expansion under heat and corresponding contraction in low-temperature environments.
Water Resistance
The polymer chains of silicone contain numerous methyl groups (a type of organic functional group). These methyl groups are non-polar and thus are not attracted to polar water molecules, resulting in a hydrophobic surface. Furthermore, when silicone products are used as surface materials, the methyl groups form an effective barrier that prevents water from penetrating the material’s interior. When water comes into contact with a silicone surface, it beads up and rolls off easily, allowing external moisture to be readily shed. Additionally, the material’s gas permeability enables internal moisture to escape. These combined properties give silicone its excellent water resistance.
Acrylic exhibits a moderate level of hydrophobicity, which primarily relies on its smooth surface finish rather than a durable and stable molecular structure like silicone. The smooth surface facilitates the beading of water droplets. However, this hydrophobic property is not permanent and can be compromised by surface scratches or abrasion. When abraded acrylic is exposed to water, the liquid tends to spread and remain on the surface instead of forming beads. This makes the material appear hydrophilic and often leads to the formation of water stain residues.
Cost
Silicone is significantly more costly than acrylic, primarily due to its higher production expenses. The raw material cost begins with the extraction of silicon, which must then undergo complex chemical synthesis to produce silicone. In contrast, acrylic benefits from a more mature and straightforward synthesis process, resulting in lower material costs.
The manufacturing process for silicone is also more intricate, requiring the mixing of different components and a series of steps like vulcanization. This longer production cycle inherently increases its cost.
Acrylic manufacturing is considerably simpler. It can be formed in a single step through casting or extrusion, making the production process more direct, rapid, and far more conducive to large-scale continuous manufacturing. Consequently, its production efficiency substantially outpaces that of silicone.
If you require exceptional water resistance, UV protection, and anti-aging properties without budget constraints, silicone is your ideal choice. For cost-sensitive applications where hydrophobicity and UV resistance are less critical, acrylic provides a practical alternative.
Applications
Silicone
Automotive
Silicone oil is widely used as a lubricant in the automotive industry due to its temperature resistance, water insolubility, and low tendency for dirt accumulation. Furthermore, silicone rubber serves as insulation for spark plug wires and engine wiring, and also functions as a sealing compound for safety airbag systems.
Cookware
Silicone is skin-friendly, non-toxic, environmentally low-impact, chemically stable, and exhibits excellent temperature resistance, making it a premier material for kitchenware. Oven mitts made from silicone can directly contact baked goods without risk. Its reliable performance in cold environments also makes it suitable for refrigeration molds, such as ice cube trays. Furthermore, owing to its good oil and water resistance, silicone is widely used to produce kitchen utensils like basting brushes and spatulas.
Electronic
Silicone enhances the stability of electronic components against mechanical shock and vibration when used for encapsulation. Its durability and high performance make it suitable for applications in extreme environments.
However, the use of silicone in electronic devices also presents certain issues. For instance, it can be corroded by certain solvents, and the residual gases or liquids released after corrosion may migrate to other electronic components, potentially causing malfunctions.
Silicone is also widely applied in everyday electronic products, such as silicone buttons and silicone phone cases.
Beyond these applications, silicone is also utilized in mold making, 3D printing, as a fire-retardant coating, and even in aerospace applications, etc..
Acrylic
Pure acrylic typically cannot be directly sold as a final product. It generally requires the addition of comonomer additives or reinforcing fillers to enhance its toughness and strength, thereby meeting diverse application requirements under various conditions.
Glass Substitute
Acrylic’s transparency, strength, and resistance to shattering into sharp fragments make it an ideal substitute for glass. It is commonly employed in the construction of residential buildings, aquariums, and similar structures. Furthermore, its applications extend to office building windows, automotive light covers, bullet-resistant windows for police vehicles, and aircraft windows.
Medicine
Acrylic exhibits biocompatibility, enabling direct contact with human tissues. It serves as an ideal material for intraocular lenses in cataract surgery, with minimal risk of causing inflammation. Furthermore, acrylic is widely used in ophthalmic lenses for eyeglasses. Soft contact lenses are also fabricated from related polymeric materials, demonstrating notable hydrophilic properties. Beyond these applications, acrylic finds extensive use in cosmetic surgery and the fabrication of artificial teeth, among other medical and dental applications.
Additionally, its versatility extends to non-medical domains such as art exhibitions, sculpture creation, and protective casings.
Conclusion
Silicone and acrylic share some overlapping applications, yet their distinct material properties make them easily distinguishable. In summary, silicone is soft, highly elastic, non-toxic,abrasion-resistant, UV-resistant, oxidation-resistant, hydrophobic, and adheres well to diverse materials. Acrylic offers excellent transparency, high rigidity, and lower cost, and can be brushed into gaps—though it demands stricter application conditions. You can confidently select the most suitable material based on your specific requirements.
FAQ
Which is better for sealants, silicone or acrylic?
In most applications requiring elastic sealing, silicone undoubtedly outperforms acrylic by a significant margin. Silicone maintains exceptional elasticity, accommodating joint movement and expansion, whereas acrylic hardens and becomes rigid upon curing, offering minimal flexibility. Furthermore, silicone demonstrates superior water resistance and adhesion compared to acrylic. The only notable drawback is that silicone sealant is more expensive than its acrylic counterpart.
Therefore, for sealing dynamic joints that require waterproofing and temperature resistance, silicone is the optimal choice for you. If the sealant is intended for filling static gaps in dry, indoor environments, acrylic presents a viable and cost-effective option for you.
Which material is stronger and more abrasion-resistant?
Silicone boasts a soft, highly elastic texture that effectively cushions against friction and compression. It resists crushing and stretching without tearing, though its pliable surface remains vulnerable to punctures by sharp objects.
In contrast, acrylic possesses a rigid surface prone to scratching, and most variants are brittle upon impact—cracking or shattering easily. Its ductility and elasticity fall far short of silicone’s performance.
Therefore, if you require a rigid protective casing that resists deformation and surface scratches—such as for transparent covers or instrument panels—acrylic is a suitable choice. If, however, you need a flexible, impact-resistant, and shock-absorbing buffer layer, silicone offers greater abrasion resistance and overall durability.
Which material is better suited for prolonged compression?
Silicone is superior to acrylic for long-term compression applications. As an elastomer, it behaves similarly to memory foam—deforming under pressure but rapidly recovering its original shape once the load is removed. In contrast, when acrylic is subjected to stress exceeding its load-bearing capacity, it undergoes permanent deformation or fractures.
Silicone performs exceptionally well in environments involving sustained compression, such as silicone washers or shock-absorbing pads for precision instruments. Acrylic, however, is better suited for use as a supporting plate rather than being subjected to compressive forces. Therefore, for components requiring rigid support, acrylic is your appropriate choice.
