When you think of silicones, you might picture the silky silicone oils in skincare products, the soft silicone used for phone cases, or the high-temperature-resistant coatings on oven interiors—products that seem vastly different in both appearance and texture yet all belong to the same “family.” The reason silicones can “shine” so brilliantly across multiple fields, from daily life to industry, lies fundamentally in their unique ability to combine both softness and hardness. Underlying this remarkable versatility are three core products: elastomers, resins, and oils. Today, we’ll lift the veil of mystery surrounding these materials and explore just what they have in common—and where they differ.

Let me start with a simple analogy: If we think of the silicone family as a “superhero team of skills,” then elastomers, resins, and oils would be three members with vastly different styles yet sharing the same core genetic code—they all share silicone’s “core skeleton,” but because their “training methods” differ, they’ve developed utterly distinct “superpowers.”

I. Common Origin and Root: The Shared Foundational Basis of the Three Products

Whether it’s a soft elastomer, a rigid resin, or a fluid oil, their “building blocks of life” are all the same—the silicon-oxygen backbone (-Si-O-). This is the organic silicon family’s most fundamental “genetic code” and the very source of their many outstanding properties. Specifically, the commonalities among these three materials primarily manifest in three aspects:

1. Consistent core architecture, superior innate performance

The Si-O bonds in the silicone backbone have an exceptionally high bond energy—452 kJ/mol—far exceeding that of carbon-carbon bonds (346 kJ/mol). This inherent property gives them a natural advantage in terms of “high-temperature resistance and anti-aging.” Whether exposed to high temperatures of 150℃ or subjected to prolonged ultraviolet radiation, these materials maintain structural stability and are unlikely to decompose or degrade easily. Moreover, the silicone backbone exhibits extremely strong hydrophobicity, effectively repelling water—a key factor accounting for the excellent waterproof performance shared by all three materials.

2. The molecular structure is tunable, making it adaptable to diverse needs.

Although the core skeleton is identical, the molecular side chains of these three compounds—such as methyl, phenyl, and amino groups—can all be adjusted through chemical modifications. By varying the types and proportions of these side-chain groups, we can precisely control the performance of the products—for example, making oils smoother, elastomers more resilient, and resins more resistant to high temperatures. This “customizability” enables them to meet the needs of diverse applications.

3. Safe and environmentally friendly, with a wide range of applications.

High-quality silicone products are mostly non-toxic, non-irritating, and exhibit excellent biocompatibility. Whether used in skincare products (oils) that come into contact with the skin, baby and maternal care products (elastomers), or coatings for food-contact equipment (resins), these products all meet stringent safety standards. At the same time, they also boast outstanding electrical insulation properties and exceptional resistance to chemical corrosion, making them safe and reliable for use in high-end industries such as electronics, chemicals, and healthcare.

II. Distinct Styles: The Core Differences Among the Three Products

If we say that commonalities represent the “innate genetic makeup” of these three materials, then their differences are the “fruits of their postnatal cultivation.” The core distinction lies in the degree of molecular crosslinking—simply put, the “tightness of the connections” between molecules. We can think of organosilicon molecules as individual “ropes”: oils are loose, single ropes; elastomers are elastic networks woven from these ropes; and resins are rigid solids formed by tightly interwoven ropes. This structural difference directly leads to significant variations among them in terms of shape, performance, and applications. For a clearer comparison, take a look at this table:

1. Silicone elastomer: “A soft and resilient Transformer”

The core characteristic of silicone elastomers is their “elasticity”—because their molecular structure features a moderately cross-linked network with relatively large pores, much like an elastic fishing net. This network can stretch and compress, yet it effortlessly returns to its original shape once released. Thanks to this unique property, silicone elastomers are ideal materials for applications requiring both sealing and shock absorption. For example, sealing gaskets in automobile engines must maintain a tight seal under conditions of high temperature and vibration—exactly the kind of environment where elastomers excel. Similarly, the silicone phone cases we use daily not only protect our phones but also allow them to be bent and shaped freely—all thanks to the remarkable elasticity of these materials.

Depending on the cross-linking method, elastomers are divided into two types: room-temperature vulcanization and high-temperature vulcanization. Room-temperature vulcanized silicone rubber can cure at ambient temperature, making it suitable for on-site applications (such as sealants for doors and windows). High-temperature vulcanized silicone rubber requires molding at elevated temperatures and offers more stable performance, making it ideal for mass production of silicone products.

2. Silicone Resin: “A Rigid, High-Temperature-Resistant Protective Shield”

If elastomers are the “soft bones,” then resins are the “hard backbone.” Their molecules form a highly cross-linked network with extremely dense pores, in which the molecules are tightly “embraced” by one another. As a result, they exhibit exceptionally high hardness and can withstand extreme high temperatures. The most common application is in high-temperature-resistant coatings—for instance, the coating on the inner walls of ovens, which can endure temperatures above 250°C and prevent food from sticking. Another prominent use is in coatings for aerospace components, enabling them to withstand the intense heat and radiation found at high altitudes.

Moreover, resin has strong adhesive properties and can also be used as an adhesive—for instance, to bond together different materials such as metals and ceramics—while simultaneously providing insulation and corrosion resistance. However, it does have some drawbacks: due to its extreme hardness, it is relatively brittle and cannot withstand severe impacts or tensile forces.

3. Silicone Oil-Based: “A Smooth and Fluid Lubricant”

The molecules of silicone oil products are linear with virtually no cross-linking—much like individual, independent “ropes”—which allows them to flow freely and feel smooth to the touch. This is precisely why silicone oil serves as a key ingredient in skincare and cosmetic formulations: when applied to the skin, it forms a lightweight protective film that leaves the skin feeling silky smooth and helps lock in moisture. At the same time, silicone oil exhibits outstanding lubricity and antifoaming properties—for instance, when used as a lubricant in machinery, it reduces wear and tear; and in industrial production, as an antifoaming agent, it effectively eliminates bubbles from liquids.

Depending on their viscosity, silicone oils are divided into two types: low-viscosity (as thin as water) and high-viscosity (as thick as honey). Low-viscosity silicone oils are suitable for use as lubricants and defoamers, while high-viscosity silicone oils are ideal for sealants and mold-release agents. Additionally, modified amino silicone oils can be used in the textile industry to make fabrics softer and smoother.

III. How to Select the Right Model? 3 Core Principles

Now that we’ve understood the commonalities and differences among the three, how should we choose in practical applications? Actually, it’s quite simple—just remember these three principles:

1. Requirements for “flexibility, sealing, and shock absorption”—choose silicone elastomers: For instance, if you need seals for doors and windows or automotive components, or soft-touch baby and maternal products and medical catheters, elastomers should be your top choice.

2. If you need a material that is “hard, high-temperature resistant, and protective”—choose silicone resin. For example, silicone resin is the ideal choice for coatings on high-temperature equipment, encapsulation of electronic components, and bonding between different materials.

3. For applications requiring “lubrication, defoaming, and smoothness”—choose silicone oils: for instance, in skincare ingredients, mechanical lubricants, textile softeners, and industrial defoamers—silicone oil products can precisely meet these needs.

IV. Summary: The silicone that combines both “softness and hardness” holds great promise for the future.

Silicone elastomers, resins, and oils—though vastly different in form and performance—share a common origin: the exceptional properties of their siloxane backbone. It is precisely this “same genetic code yet diverse appearances” characteristic that enables silicones to seamlessly transition from “soft” silicone products to “hard” high-temperature-resistant coatings and even to “fluid” ingredients in skincare formulations, truly earning them the title of “industrial MSG.”

With the advancement of technology, the performance of these three materials continues to improve through modification techniques—for example, elastomers can become more resistant to high temperatures, resins can gain greater toughness, and silicone oils can become more environmentally friendly. In the future, these “soft yet strong” silicone products will play an even greater role in high-end fields such as new energy, semiconductors, and healthcare, continuing to transform both our daily lives and industrial production.