The core difference between conductive silicone and ordinary silicone materials lies in functional properties and application scenarios. The former gives the material the ability to transmit electrons through conductive fillers, while the latter focuses on insulation and elasticity. The following is a systematic comparative analysis from four dimensions: material composition, performance differences, application areas and technical difficulties:
1. Differences in material composition
Dimension Conductive silicone Ordinary silicone
Material Mainly methyl vinyl silicone rubber (VMQ), with vulcanizers, crosslinkers and other additives added Pure silicone rubber matrix (such as methyl silicone rubber, phenyl silicone rubber), only containing necessary vulcanization/processing aids
Conductive fillers Metal particles (silver, copper, nickel), carbon materials (carbon black, graphene) or conductive fibers must be added, accounting for 5-80% No conductive fillers, may add reinforcing fillers such as silica to improve mechanical properties
Auxiliary system Antioxidants (to prevent metal oxidation) and dispersants (to improve filler dispersion) are required Only basic additives such as vulcanizers and release agents are required
Analogy explanation:
Conductive silicone is like adding a "conductive particle highway" to ordinary silicone, allowing electrons to be transmitted through the filler network; while ordinary silicone is like a pure "insulating sponge", which only has physical support and sealing functions.
2. Performance Difference Comparison
Performance Index Conductive Silicone Ordinary Silicone
Conductivity Volume Resistivity 10⁻²~10⁶ Ω·cm (Silver powder filler can reach 10⁻², carbon black filler is about 10²) Volume Resistivity >10¹⁵ Ω·cm (insulation grade)
Mechanical Properties Tensile Strength 5~10 MPa, Elongation at Break 300%~800% (decreases with increasing filler) Tensile Strength 7~15 MPa, Elongation at Break 500%~1200%
Temperature Resistance -60℃~200℃ (Special formula can reach 300℃) -50℃~250℃ (some high temperature resistant models)
Electromagnetic Shielding Effectiveness Shielding Effectiveness 20~80 dB (10 MHz~18 GHz, depending on filler type and density) No shielding capability
Compression Set 10%~30% (recovery ability after long-term compression) 5%~15% (better elastic recovery)
Key conclusions:
The conductivity of conductive silicone is improved at the expense of some mechanical properties (such as reduced tensile strength and increased hardness);
Ordinary silicone has more advantages in temperature resistance and elastic recovery, but cannot achieve electronic signal transmission.
3. Differences in application scenarios
Application fields Conductive silicone Ordinary silicone
Electronic and electrical Electromagnetic shielding seals, conductive buttons, flexible circuit connectors, anti-static trays Sealing rings, gaskets, O-rings, insulating sleeves
Communication equipment 5G base station antenna seals, filter shielding, handheld terminal buttons Optical fiber sheaths, cable connector seals
Automotive electronics Conductive seals for new energy vehicle battery packs, conductive parts of sensors Engine seals, car light seals
Medical equipment Flexible electrodes, biosensors, conductive parts of wearable devices Medical catheters, artificial organ sealing layers
Industrial fields Conductive seals for high-voltage equipment, anti-static floor mats Pipeline seals, valve gaskets
Typical cases:
Conductive silicone: Conductive contacts used for mobile phone buttons must meet both the pressing life (>100,000 times) and resistance stability (<100 Ω);
Ordinary silicone: Used for water cup seals, only food-grade safety and water resistance are required.
IV. Comparison of technical difficulties
Technical difficulties Conductive silicone Ordinary silicone
Filler dispersion The problem of metal particle agglomeration needs to be solved (such as silver powder is easy to oxidize and carbon black is easy to settle), and surface modification technology needs to be used. Only the dispersion of reinforcing fillers needs to be controlled, and the process is relatively simple
Long-term stability Metal fillers are easily oxidized, resulting in increased resistance (such as copper powder increases resistance by 30% in 6 months under high temperature and high humidity) Excellent weather resistance, no performance degradation after long-term use
Cost and process The cost of silver powder accounts for more than 60% of the total material price, and low-cost composite fillers (such as nickel-coated graphite) need to be developed. Low raw material cost, mature process, high yield rate
Environmental protection requirements RoHS/REACH regulations need to be met, and some metal fillers may be banned Natural silicone is biodegradable and has significant environmental advantages
5. Summary and selection suggestions
Scenario for selecting conductive silicone:
Electronic signal transmission or electromagnetic shielding function is required;
Sealability and conductivity need to be met at the same time (such as high-voltage equipment, aerospace);
Acceptable cost increase (usually 30%~200% higher than ordinary silicone).
Scenarios for choosing ordinary silicone:
Only insulation, sealing or buffering functions are required;
Cost-sensitive (such as daily necessities, industrial seals);
Long-term exposure to high temperature, high pressure or chemical corrosion environment (ordinary silicone has better weather resistance).
Final conclusion:
Conductive silicone is a functional modified material with conductivity as its core competitiveness; ordinary silicone is a basic elastomer material with cost and versatility. There is no absolute advantage or disadvantage between the two, and the choice needs to be based on specific application requirements.