Silicone materials occupy a crucial position in the industrial sector thanks to their outstanding properties, including resistance to extreme temperatures, weathering resistance, insulation performance, and chemical stability. Among these, hydrogen-containing silicone oils and vinyl silicone oils—key subcategories of specialty silicones—possess unique chemical reactivity and functional characteristics achieved through precise molecular design. They have found extensive applications across multiple high-end manufacturing sectors, such as new energy, electronics, textiles, and healthcare, making them pivotal materials driving industrial upgrades. This article will focus on the distinctive features of these two types of silicone oils, combining practical industrial scenarios to provide a detailed analysis of their application value and the current state of industry development.

I. Hydrogen-Containing Silicone Oil: A Versatile Specialty Material Driven by Activity

The chemical name of hydrogen-containing silicone oil is poly(methylhydrogen siloxane). Its molecular chain contains reactive Si-H bonds. This core structure endows it with unique chemical activity and functional properties, setting it apart from conventional methyl silicone oils. It enables a variety of functions, including crosslinking, modification, and surface treatment, and exhibits outstanding adaptability to extreme environmental conditions.

(1) Core Special Features

1. Low-Temperature Crosslinking and Film-Forming Properties: Under the catalytic action of metal salt catalysts, hydrogen-containing silicone oils can undergo crosslinking reactions at relatively low temperatures, forming a dense three-dimensional network structure. After film formation, the original properties of the substrate remain unaffected, and the resulting film exhibits excellent adhesion and toughness. By precisely controlling the amount of catalyst used and the reaction temperature, the crosslinking reaction enables fine-tuned control over both the film-forming rate and the performance of the film layer, thereby meeting the specific requirements of various application scenarios.

2. Ultra-hydrophobic and oleophobic properties: The molecular structure of hydrogen-containing silicone oil features an extremely low surface tension. After film formation, it creates a nanoscale waterproof barrier on the surfaces of various substrates, effectively preventing the penetration of moisture and oil stains while maintaining the substrate’s porosity and breathability. Materials treated with this substance exhibit a significantly reduced water absorption rate, and their waterproof rating can be elevated to higher standards.

3. Chemical modification activity: The Si-H bond can undergo hydrosilation reactions with a variety of unsaturated compounds, making it an important intermediate for organosilicon modification. It can be used to synthesize derivative materials such as polyether-modified silicone oils and long-chain alkyl silicone oils, enabling customized functional enhancements. Meanwhile, it can also serve as a crosslinking agent, working synergistically with other organosilicon materials to optimize the mechanical properties and operational stability of these materials.

4. Extreme Environmental Tolerance: Hydrogen-containing silicone oil maintains a stable molecular structure even under high-temperature conditions (up to 700℃), showing no decomposition or yellowing. In low-temperature environments, it neither solidifies nor becomes brittle. Additionally, it exhibits excellent resistance to acids, bases, and ozone, making it well-suited for the complex operating conditions encountered in industrial production.

(2) Major Industrial Applications

1. In the field of silicone synthesis: As the core crosslinking agent for addition-type liquid silicone rubber (LSR), hydrogen-containing silicone oil, through platinum-catalyzed reactions with other silicone materials, forms Si-C bonds and constructs a three-dimensional network structure. This makes it ideal for producing highly safety-critical products such as baby nipples and medical catheters. Meanwhile, as a modifying intermediate, it can be used to synthesize derivative products like polyurethane foam stabilizers and cosmetic emulsifiers, thereby expanding the application scope of silicones.

2. Textile and Apparel Industry: The combination of hydrogenated silicone oil emulsions with hydroxyl silicone oils can be used for surface treatment of fabrics, imparting them with breathable, waterproof, wear-resistant, and tear-resistant properties. At the same time, this formulation optimizes the fabric’s hand feel, giving it a silky-smooth texture. It is widely used in the production of high-end outdoor apparel and medical protective clothing. In addition, it can serve as a lubricant for sewing threads, reducing thread breakage during high-speed sewing and thereby improving production efficiency.

3. Construction and Building Materials Sector: As a specialized waterproofing agent, hydrogen-containing silicone oil can be used for surface treatment of building materials such as gypsum boards, marble curtain walls, and polished tiles. It reduces the water absorption rate of gypsum boards to below 10%, effectively resisting rainwater erosion and extending the service life of these materials. Meanwhile, it can also treat electrical-grade magnesium oxide powder, preventing high-voltage insulating materials from becoming damp and causing electrical leakage, thereby ensuring electrical safety.

4. Electronics and New Energy Fields: Electronic components treated with hydrogen-containing silicone oil exhibit excellent insulation and moisture-proof properties, enhancing the stability and service life of electronic devices. In the new energy sector, this material can serve as an auxiliary component in battery assemblies, optimizing battery sealing performance and reducing the impact of environmental factors on battery performance.

5. Other applications: Hydrogen-containing silicone oils can serve as surface treatments for dry-powder fire extinguishing agents, enhancing their hydrophobic properties and extinguishing efficiency. They can also be used as water- and corrosion-resistant coatings for leather and wood, thereby extending the service life of these products. In the cosmetics industry, low-volatility, highly biocompatible hydrogen-containing silicone oil derivatives can be incorporated into formulations for skincare products and makeup, improving product feel and stability.

II. Vinyl Silicone Oil: A High-End Functional Material with Tunable Crosslinking

Vinyl silicone oil features a polydimethylsiloxane backbone with vinyl groups introduced into the side chains. This design not only retains the core advantages of conventional silicone materials—such as excellent resistance to high and low temperatures and outstanding weatherability—but also enables precise control over crosslinking density thanks to the reactivity of the vinyl groups. As a result, it boasts excellent processability and functional versatility, making it an indispensable specialty material in the high-end manufacturing sector.

(1) Core Special Features

1. Controllable Crosslinking Properties: The vinyl groups in the molecular chains of vinyl silicone oils can undergo addition reactions with hydrogen-containing silicone oils and other substances. By precisely controlling the vinyl content (ranging from 0.1% to 2%), the crosslinking density can be accurately adjusted, thereby fine-tuning the mechanical properties of the cured material, such as hardness and elasticity. The hardness can be increased by 3 to 5 points on the Shore A scale, meeting customized requirements for various applications.

2. Excellent Light Transmittance and Stability: Vinyl silicone oil itself boasts good light transmittance. When compounded with MQ resin and subsequently cured, its light transmittance can exceed 90%, and its refractive index can be adjusted to between 1.41 and 1.53, achieving high compatibility with the refractive indices of electronic chips and LED chips. Meanwhile, it exhibits outstanding resistance to UV aging; after curing, it can maintain a light transmittance of over 85% even when continuously operated at a high temperature of 150℃ for 10,000 hours.

3. Excellent processability: Vinyl silicone oil has low viscosity and excellent fluidity, allowing it to be processed via a variety of methods—including injection molding, potting, and coating—thus accommodating the production of products with diverse shapes and specifications. Moreover, the processing does not produce significant volatile substances, making it compliant with green manufacturing requirements. It exhibits good compatibility with conductive fillers and reinforcing fillers, enabling functional enhancements through composite modification.

4. Biocompatibility: Medical-grade vinyl silicone oil meets the USP Class VI standard, exhibits low cytotoxicity, elicits only mild inflammatory responses upon implantation in vivo, and demonstrates excellent biocompatibility, making it suitable for the manufacture of medical implant devices.

(2) Major Industrial Applications

1. Optoelectronics and Electronics: In LED packaging, a composite material made of vinyl silicone oil and MQ resin, cured with a platinum catalyst, can produce a high-strength, highly transparent encapsulant that effectively protects LED chips, enhances chip luminous efficiency, and extends chip service life—making it a core material for high-power LED lighting. In the semiconductor industry, vinyl silicone resins with low cyclic impurity levels can meet the stringent requirements of Chiplet advanced packaging processes regarding thermal expansion coefficients (15–18 ppm/℃), and are thus used in critical areas such as underfill materials for chips.

2. Medical Field: As the base polymer for medical silicone implants, vinyl silicone oil, by controlling its degree of crosslinking, can yield materials with mechanical properties that closely match those of human tissues, making it suitable for the production of medical devices such as breast implants and medical catheters. Meanwhile, it can also serve as a carrier in drug-delivery systems, leveraging the controlled-release characteristics of silicone rubber to achieve precise drug administration and enhance therapeutic efficacy.

3. Automotive and New Energy Fields: Liquid silicone rubber (LSR) containing vinyl silicone oil reduces injection molding time by 30% compared to conventional materials. At 140°C, its tear strength can reach up to 25 kN/m. It is widely used in the production of automotive seals and vibration-damping components, particularly well-suited for sealing applications in the 800V high-voltage platforms of new-energy vehicles. In the wind power sector, its excellent weather resistance makes it ideal for developing protective coatings for turbine blades; after undergoing a 3,000-hour salt-spray test, the coating surface showed no cracking, and its hydrophobic contact angle remained above 115°.

4. Cosmetics and Flexible Electronics: The compatibility between modified vinyl silicone oil and color pigments has improved by 40% compared to conventional materials, making it suitable for use in makeup products such as eyeshadows and foundations, thereby enhancing color intensity and long-lasting performance. Nano-sized vinyl silicone oil particles can be incorporated into high-end skincare products to form a lightweight, breathable protective film that improves skin feel. In the field of flexible electronics, stretchable conductors prepared by compounding these silicones with conductive fillers exhibit a resistance change rate of less than 5% even under 100% strain, providing crucial material support for wearable devices and flexible electronic skins.

5. Other Applications: Vinyl silicone oil can be used in 3D printing of photosensitive resins, breaking through bottlenecks in the manufacturing of precision components. As a modifier in rubber processing, it can enhance the mechanical properties of silicone rubber, such as tensile strength and tear resistance. In the coatings industry, it can be used to produce industrial coatings with outstanding weather resistance and abrasion resistance, meeting the surface protection requirements of high-end equipment.

III. Current Status and Trends in Industry Development

In recent years, driven by both innovations in molecular structure and growing demand for high-end downstream manufacturing, the hydrogen-containing silicone oil and vinyl silicone oil industries have experienced rapid growth. As a global hub of silicon-based material production capacity, China saw its domestic output of specialty silicon monomers reach 680,000 tons in 2024, representing a year-on-year increase of 12.3%. Among these, the share of high-end functional products such as hydrogen-containing silicone oil and vinyl silicone oil has continued to rise. Currently, Chinese companies have achieved breakthroughs in areas such as high-purity products and green synthesis processes through technological innovation, gradually breaking the technological monopoly held by international giants. In 2024, the localization rate in related sub-sectors had already climbed to 58%, and it is projected that by 2026, the localization rate of semiconductor-grade materials will exceed 40%.

In the future, as demand rises in high-end sectors such as new energy, semiconductors, and healthcare, hydrogen-containing silicone oils and vinyl silicone oils will evolve toward higher purity, lower volatility, and customized functionalities. The application of AI-assisted molecular design and continuous-flow microreactor technology will shorten product development cycles and enhance product performance stability. The widespread adoption of green synthesis processes will reduce environmental pollution during production, aligning with the “dual-carbon” goals. Meanwhile, the ongoing expansion of downstream application scenarios will further unleash market demand for these products, driving the specialty silicone industry toward a stage of high-quality development.

IV. Conclusion

Hydrogen-containing silicone oils and vinyl silicone oils, as core representatives of specialty silicones, have become a crucial link connecting molecular structure innovation with industrial applications thanks to their unique functional characteristics. Hydrogen-containing silicone oils, driven by the reactivity of Si-H bonds, enable multifunctional adaptations such as waterproofing, crosslinking, and modification. Vinyl silicone oils, on the other hand, leverage the controllable crosslinking capability of vinyl groups to meet the precise performance requirements of high-end manufacturing. The widespread application of these two types of silicone oils across multiple industrial sectors has not only enhanced the performance and quality of end products but also spurred technological upgrades in related industries. As industry technologies continue to advance and demand keeps growing, the application scope of hydrogen-containing silicone oils and vinyl silicone oils will further expand, providing stronger material support for the development of high-end manufacturing industries.