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AEROSIL® R 202

AEROSIL® R 202 is a hydrophobic fumed silica grade, treated with a polydimethylsiloxane. This product can be used in defoamer formulations for sedimentation stabilization and due to its high hydrophobicity as defoaming component.

Brand: AEROSIL (33 products)

INCI Name: Silica Dimethicone Silylate

Chemical Name: Hydrated Silica, Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-,hydrolysis products with silica, Silica gel, pptd., cryst.-free

Functions: Defoamer, Rheology Modifier, Thickener, Thixotrope, Viscosity Modifier

Chemical Family: Silica

Enhanced TDS

Enhanced TDS

Knowde-enriched technical product data sheet

Identification & Functionality

Features & Benefits

Benefit Claims
Labeling Claims
CASE Ingredients Features
Fluids & Lubricants Features
Materials Features
Product Features
  • The silicone oil treatment guarantees the marked hydrophobia of the product
  • Highly efficient effect in the thickening and thixotropy of complex polar liquids, such as those based on epoxy, polyurethane, or vinylester resins
  • With silicone oil treatment, AEROSIL® R 202 offers a tailor-made chemical surface treatment.
  • The high hydrophobicity of PDMS-treated, small particle AEROSIL® grades makes them particularly effective for achieving a high tribo-charge.
  • At the same time, PDMS-treated, small particle AEROSIL® grades maintain good flowability.

Applications & Uses

Markets
Applications
Compatible Polymers & Resins
Fluids & Lubricants Type
Fluids & Lubricants End Use
Plastics & Elastomers End Uses
Plastics & Elastomers Processing Methods
AEROSIL® Fumed Silica in Lubricating Greases

AEROSIL® fumed silica helps to build a stable matrix to increase viscosity and suppress oil separation in lubricating greases. It can be used in the following systems:

  • In non-soap greases, used in high-temperature applications up to 230° C as well as for extreme-pressure and multipurpose greases.
  • In soap greases, thickened by fatty acid soaps of lithium, calcium, sodium or aluminum, AEROSIL® fumed silica can be used to further improve the performance of the lubricating grease.
  • Hydrophilic fumed silica provides optimized thickening effects in non-polar oils.
  • Hydrophobic fumed silica provides viscosity control and increased water repellency in semi-polar to polar oils.
  • The surface area of the silica and the volume fraction of the silica in the fi nal mass play a role in the long term storage and heat stability.
Cable Gel Applications

Use of AEROSIL® fumed silica for cable gels gives excellent performance when it comes to shear-thinning, providing quick recovery and the gel does not require heat to be applied. AEROSIL® fumed silica improves properties of oil-based filling compounds for wire and cables to protect fibers (e. g. optical fibers) as it:

  • Supports to isolate sensitive optical fi bers from external forces
  • Protects the fi bers from moisture
  • Provides thickening to help the gel to stay where it is placed
  • Helps to form a seal to keep out contaminants like dust, dirt and water
  • Is non-conductive / does not negatively infl uence di-electrical properties
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Applications
  • Thickening and thixotropy control of adhesives and sealants for fiberoptic cables
  • Thickening and thixotropy control of epoxy and vinylester resins
  • Booster silica for defoamer formulations
  • Anti-sedimentation aid for fillers, such as chalk or quartz powder
  • Additive for formulation of anti-corrosion systems
  • Improves flowability of powders
  • Enables achieving of a high tribo-charge
Lubricating Grease Applications

The use of AEROSIL® fumed silica is recommended for lubricating greases used in industrial applications, automotive, electrical as well as food grade.

  • Electrical - Offers rheology control as well as water resistance.
  • Industrial - Offers rheology control as well as excellent oxidation resistance against water and chemicals.
  • Automotive - Offers rheology control as well as excellent oxidation resistance against water and chemicals.
  • Food - Hydrophilic AEROSIL® are generally recognized as safe (GRAS; direct food contact). Offers rheology control as well as water resistance

Properties

Physical Form
Appearance
Fluffy white powder
Physico-Chemical Properties
ValueUnitsTest Method / Conditions
Unit Weight (Netto)10kg-
HCI Content⁸,¹¹max. 0.025wt %-
TiO₂ Content⁸max. 0.030wt %-
Fe₂O₃ Content⁸max. 0.010wt %-
Al₂O₃ Content⁸max. 0.050wt %-
SiO₂ Content⁸min. 99.8wt %-
Carbon Content3.5 - 5.0wt %-
pH Value⁵ (4%, Aqueous dispersion)4.0 - 6.0 10wt %-
Loss on Ignition⁴,⁷ (2h at 1000°C)4.0 - 6.0wt %-
Loss on Drying³ (2h at 105°C, when leaving the plant)max. 0.5wt %-
Tamped Density²60g/l-
BET Surface Area (BET¹)80 - 120m²/g-
Behavior Towards WaterHydrophilic--
Note

1 - According to DIN 9277
² - According to DIN EN ISO 787/11, JIS K 5101/20 (not sieved)
3 - According to DIN EN ISO 787/2, ASTM D 280, JIS K 5101/23
4 - According to DIN EN ISO 3262-20, ASTM D 1208, JIS K 5101/24
5 - According to DIN EN ISO 787/9, ASTM D 1208, JIS K 5101/26
6 - According to DIN EN ISO 787/18, JIS K 5101/22
7 - Based on dried substance (2 hours at 105 °C)
8 - Based on ignited substance (2 hours at 1000 °C)
9 - Special moisture-protective packaging
10 - in water: methanol = 1:1
11 - HCI-content is a part of ignition loss
12 - Packaging of densed material: 20 kg

Note

* ex plant

Regulatory & Compliance

Technical Details & Test Data

Test Methods
  • AEROSIL® fumed silica is a highly dispersed, amorphous, very pure silica manufactured by high-temperature hydrolysis of silicon tetrachloride in an oxyhydrogen gas flame. The primary particles formed in the AEROSIL® process are virtually spherical and free of pores.
  • During the formation of the primary particles, aggregates are formed which further accumulate into agglomerates. Under shear, these agglomerates can be returned back into smaller aggregates.
  • Siloxane and silanol groups are found on the surface of the AEROSIL® particles. This latter type of functional group in particular is responsible for the hydrophilic behavior of untreated AEROSIL®. Figure shows the surface groups of hydrophilic AEROSIL® grades.

AEROSIL® R 202 - Aerosil® Fumed Silica

Surface groups of hydrophilic AEROSIL® grades.

Figure below provides a summary of these and highlights the difference between them and hydrophilic AEROSIL® grades according to the schematically represented surface groups. All hydrophobic AEROSIL® grades bear the suffix "R" to indicate their water- repellent character.

AEROSIL® R 202 - Aerosil® Fumed Silica - 1

Surface groups of hydrophobic AEROSIL® grades.

The hydrophobic nature of aftertreated AEROSIL® grades compared with AEROSIL® 300 can be illustrated by means of moisture adsorption in increasingly humid conditions. Figure below shows the corresponding isotherms.

AEROSIL® R 202 - Aerosil® Fumed Silica - 2

Adsorption isotherms of various AEROSIL® grades at room temperature (small samples).

AEROSIL® Fumed Silica
  • AEROSIL® fumed silica is a highly dispersed, amorphous, very pure silica manufactured by high-temperature hydrolysis of silicon tetrachloride in an oxyhydrogen gas flame. The primary particles formed in the AEROSIL® process are virtually spherical and free of pores.
  • During the formation of the primary particles, aggregates are formed which further accumulate into agglomerates. Under shear, these agglomerates can be returned back into smaller aggregates.
  • Siloxane and silanol groups are found on the surface of the AEROSIL® particles. This latter type of functional group in particular is responsible for the hydrophilic behaviour of untreated AEROSIL®. Figure shows the surface groups of hydrophilic AEROSIL® grades.

AEROSIL® R 202 - Aerosil® Fumed Silica

Surface groups of hydrophilic AEROSIL® grades.

Figure below provides a summary of these and highlights the difference between them and hydrophilic AEROSIL® grades according to the schematically represented surface groups. All hydrophobic AEROSIL® grades bear the suffix "R" to indicate their water- repellent character.

AEROSIL® R 202 - Aerosil® Fumed Silica - 1

Surface groups of hydrophobic AEROSIL® grades.

The hydrophobic nature of aftertreated AEROSIL® grades compared with AEROSIL® 300 can be illustrated by means of moisture adsorption in increasingly humid conditions. Figure below shows the corresponding isotherms.

AEROSIL® R 202 - Aerosil® Fumed Silica - 2

Adsorption isotherms of various AEROSIL® grades at room temperature (small samples).

Packaging & Availability

Country Availability
Packaging Type
Regional Availability
  • North America
Packaging Information

AEROSIL® R 202 is supplied in multiple layer 10 kg bags.

Storage & Handling

Shelf Life
2 years
Storage Conditions

Recommend to store the product in closed containers under dry conditions and to protect the material from volatile substances. AEROSIL® R 202 should be used within 2 years after production.