Application of silicone materials in polymer elastomers

Silicone materials have a wide range of applications in polymer elastomers. Their unique molecular structure (organic Si-O-Si side chains) provides properties such as resistance to high and low temperatures, weather resistance, electrical insulation, and physiological inertness. The main applications include Silicone Rubber matrices, modified additives, and hybrid materials.

I. As an elastomer matrix: silicone rubber

1. Classification and characteristics
●High Temperature Vulcanized Silicone Rubber (HTV): Vulcanized using peroxides or addition reactions, it has high strength (tensile strength >30 kN/m) and temperature resistance up to 250°C, making it suitable for applications such as aerospace seals and medical catheters.
●Room Temperature Vulcanized Silicone Rubber (RTV): Vulcanized by condensation or addition reaction, it provides easy handling and deep curing, used in building sealants, mold making, etc.
●Liquid Silicone Rubber (LSR): Vulcanized by platinum-catalyzed addition reactions, provides fast injection molding (

2. Operational advantages
●Temperature resistance range: from -60°C to 250°C (short-term 300°C).
● Chemical stability: resistant to ozone, UV radiation and most solvents (except ketones/alkanes).
●Biocompatibility: Certified to USP Class VI standards (e.g. medical implant materials).
●Electrical properties: volume resistivity >10¹⁵Ω·cm, dielectric strength >20 kV/mm.

II. IN quality modifier for traditional rubber

1. Optimization of processing and performance
●Plasticization and lubrication: The addition of 3-5% diMethyl Silicone Oil (viscosity 50-1000 cSt) reduces the viscosity of Mooney NR/SBR by 20% and reduces energy consumption during mixing. Improves surface smoothness during EPDM extrusion and eliminates the sharkskin phenomenon.
●Improves filler dispersion: Silane coupling agent Si-69 treated with silica increases tread abrasion resistance by 30% (abrasion volume reduced to 0.08 cm³/1.61 km).
●Dynamic performance adjustment: Hydroxyl-modified carbon black reduces the tire's rolling resistance by 15%.

2. Functional modification
●Improved heat resistance: Phenyl silicone resin mixture (10-15 parts) increases the heat resistance temperature of NBR from 120°C to 180°C.
●Fire resistance synergy: Hydrogen-containing silicone oil and ATH platinum catalyst increases the oxygen index of EPDM to >35%.
●Increased adhesion: Aminosilane primer increases the adhesion strength of rubber to metal (peel strength >8 kN/m).

III. Silicone-based hybrid elastomers

1. Interpenetrating network
●Silicone-Polyurethane: Polyurethane prepolymer and vinyl silicone oil are co-cured, achieving a tensile strength of 25 MPa and an elastic recovery of >95%. By copolymerizing silicone monomers with polyurethane monomers, elastomers can be obtained that have the advantages of both. Grafting silicone segments onto the polyurethane backbone improves the surface properties and mechanical properties of the elastomer, while avoiding the performance degradation caused by microphase separation. For example, polyurethane elastomers modified with a silicone block copolymer retain the elasticity of polyurethane while significantly improving hydrophobicity and heat resistance. Applications include high-rebound shock absorbers and artificial heart valves.
●Silicone-acrylate: Acrylate and thiol silicone oil curing systems achieve light transmittance >92% and yellowing resistance (ΔYI

2. Nanocomposite reinforcement

●Nanosilica is hydrophobized using hexamethyldisilazane, resulting in a 40% increase in tensile strength (up to 50 kN/m). It is used in the insulation layers of high-voltage cables. The cage-like siloxane copolymerizes with octaethylenedione, increasing its thermal decomposition temperature by 60°C (up to 550°C). It is used in spacecraft seals.