Surface Activated Thermally Conductive Silica

A High Purity, High Thermal Conductivity, High Insulation Engineered Filler

 As a professional Rubber filler factory China, GreenThinking® develops and manufactures advanced functional fillers for global rubber and polymer industries. The SF210 product is a high thermal conductivity silica filler that also serves as a high purity electrical insulation filler, making it an ideal choice for demanding electronic and thermal management applications. Backed by expertise as Rubber Functional filler Manufacturers China and Rubber reinforcing filler Manufacturers China, GreenThinking® delivers consistent, highperformance solutions.

GreenThinking® SF210 is a surface activated thermally conductive powder  a highpurity, highwearresistant thermally conductive silica refined from highpurity quartz and subjected to surface activation treatment. The product remains stable and inert in the presence of catalysts or multicomponent chemical systems, and does not degrade under extreme temperatures or harsh environments. SF210 exhibits high whiteness, chemical inertness, high wear resistance, high thermal conductivity, and excellent electrical insulation, significantly improving the weather resistance and chemical stability of polymers. As a thermally conductive filler for silicone rubber, SF210 enables efficient heat dissipation while maintaining electrical isolation. This report evaluates SF210’s typical physical and performance data, assessing its value as a thermally conductive / reinforcing filler in rubber, plastics, adhesives, epoxy resins, and silicone rubbers.

Sustainable Development and ESG Strategy

1. Product Overview

SF210 is a functional silica manufactured from highpurity quartz through fine processing and surface activation. The surface modification improves compatibility and dispersion in organic matrices while retaining the inherent high hardness, high thermal conductivity, and insulation properties of silica. As a high thermal conductivity insulating filler for rubber, SF210 combines three critical attributes: thermal conductivity >10 W/(K·m), electrical insulation (Dk 4.66, Df 0.0018), and reinforcement capability.

Property	Unit	Typical Value
Appearance	—	White powder
Density	kg/m³	2.64×10³
Mohs hardness	—	7
Dielectric constant (Dk)	εr	4.66
Dielectric loss (Df)	tanδ	0.0018
Coefficient of linear thermal expansion	1/K	14×10⁻⁶
Thermal conductivity	W/(K·m)	12.5

Form: White powder
Typical bulk density: 2.64×10³ kg/m³
Mohs hardness: 7

2. Key Performance Parameters

Particle size distribution (Laser particle size analyzer MS2000):

• D50: 1.72 μm
• D100: 7.43 μm

Chemical purity:

• SiO₂: 99.4%
• Fe₂O₃: 0.012%

Whiteness: ≥ 95
Moisture: ≤ 0.12%

3. Performance Advantages and Mechanism

Property	SF210 Performance	Mechanism
High thermal conductivity	12.5 W/(K·m)	Quartz crystal has inherently high thermal conductivity, far exceeding organic polymers (approx. 0.2 W/(K·m)). This makes SF210 the best thermally conductive filler for silicone rubber compound among nonmetallic options.
High electrical insulation	Dk 4.66, Df 0.0018	Highpurity silica is an excellent insulator, suitable for electronics applications where high purity electrical insulation filler is required.
Surface activation	Improved compatibility with organic matrices	Activation reduces surface polarity, reduces agglomeration, improves dispersion – a true surface activated thermally conductive powder.
High hardness / wear resistance	Mohs hardness 7	Quartz particles provide a rigid skeleton, improving abrasion resistance. This qualifies SF210 as a high wear resistant thermally conductive filler for rollers and other dynamic rubber components.
Low thermal expansion	CTE 14×10⁻⁶ /K	Close to CTE of metals and electronic components, reducing thermal stress.
Chemical inertness	SiO₂ ≥ 99.4%, very low Fe₂O₃	Resists acids/bases, does not catalyze polymer degradation.

4. Applications

SF210 is suitable for polymer systems requiring a combination of thermal conductivity, electrical insulation, and wear resistance:

Application Area	Typical Use	Core Value
Thermally conductive silicone rubber	Thermal pads, thermally conductive potting compounds	As a thermally conductive filler for silicone rubber, SF210 enables high filler loading, thermal conductivity while maintaining electrical insulation.
Epoxy potting compounds	Electronic encapsulation	High thermal conductivity + high insulation + low CTE. Serves as a high thermal conductivity insulating filler for rubber and epoxies alike.
Highperformance rubber compounds	Rollers, wearresistant parts	Improved wear resistance and heat dissipation; specifically functions as a high wear resistant thermally conductive filler for rollers.
Plastics modification	Engineering plastics (PA, PBT, PP)	Reinforcement, thermal conductivity, dimensional stability.
Adhesives / coatings	Structural adhesives, insulating coatings	Increased hardness, thermal conductivity, reduced shrinkage stress.

For silicone rubber formulators seeking the best thermally conductive filler for silicone rubber compound, SF210 consistently outperforms conventional quartz or metal oxide fillers in combined thermalelectrical performance.

5. Processing Recommendations

• Dispersion: The activated surface aids dispersion. Use internal mixers, twinscrew extruders, or highspeed dispersers. For highloading systems, consider staged addition.
• Loading: Typical loading in silicone rubber ranges from 100 to 300 phr (per 100 parts rubber). Optimise based on viscosity and thermal conductivity requirements.
• Drying: Moisture content is very low (≤ 0.12%). Predrying is generally not required. For moisturesensitive systems (e.g., polyurethane), dry at 120°C for 2 hours before use.
• Blending with other fillers: Can be combined with alumina, boron nitride, or other thermally conductive fillers to construct multilevel thermally conductive networks.

6. Typical Performance Comparison

Property	SF210	Conventional quartz powder	Calcium carbonate	Talc
Thermal conductivity (W/(K·m))	12.5	10–12	2–3	2–4
Mohs hardness	7	7	3	1
Dielectric constant	4.66	~4.5	—	—
Surface treatment	Activated	None	None	None
Whiteness	≥ 95	85–90	90–95	85–90

7. Technical Summary

SF210 is a highpurity, surfaceactivated, highthermalconductivity, highinsulation functional silica filler. Its median particle size of 1.72 μm balances reinforcement and processing flowability. The thermal conductivity of 12.5 W/(K·m) is among the highest for nonmetallic fillers, and the dielectric constant of 4.66 with very low loss makes SF210 particularly suitable as a high purity electrical insulation filler for electronics applications. Surface activation further improves dispersion and compatibility in organic matrices, confirming its status as a surface activated thermally conductive powder.

For rubber, plastic, adhesive, and coating systems requiring simultaneous thermal conductivity, electrical insulation, wear resistance, and chemical inertness, SF210 offers a proven engineering solution. As a product from a leading Rubber filler factory China, it is backed by consistent quality and technical support from experienced Rubber Functional filler Manufacturers China and Rubber reinforcing filler Manufacturers China. Whether you need a thermally conductive filler for silicone rubber, a high wear resistant thermally conductive filler for rollers, or the best thermally conductive filler for silicone rubber compound, SF210 delivers measurable performance advantages.

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Access Technical Data and Sample Support

For complete TDS, SDS, thermal conductivity test data based on your specific formulation, or samples (1-2 kg), please visit www.sanezenrubber.com or contact yorichen@sanezen.com. Specify your application (e.g., high thermal conductivity insulating filler for rubber, thermally conductive filler for silicone rubber, or high wear resistant thermally conductive filler for rollers) to receive tailored recommendations.