CAB-O-SIL M-5 is an untreated fumed silica with a B.E.T. surface area of 200 m²/g, amorphous X-ray form, and an assay of greater than 99.8% SiO2. For formulators sourcing a rheology control and reinforcement additive, CAB-O-SIL M-5 offers documented sag resistance, anti-settling, and thickening performance based on its published technical data. This guide summarizes the verified specifications, applications, and sourcing considerations buyers should check before placing an order.
CAB-O-SIL M-5 Overview
As one of the recommended international brand products in our auxiliary agent range, this fumed silica is supplied with supply chain resource support for formulators sourcing rheology control and reinforcement additives across multiple industries.
Typical Properties
The following values are taken directly from the manufacturer’s published technical data. Buyers should request the current batch Certificate of Analysis to confirm values prior to large-volume ordering.
| Property | Value |
|---|---|
| B.E.T. surface area | 200 m²/g |
| pH (4% aqueous slurry) | 3.7-4.3 |
| 325 mesh residue (44 microns) | 0.02% max |
| Tamped density | 50 g/l |
| Loss on heating | less than 1.5% |
| Specific gravity | 2.2 g/cm³ |
| Weight per gallon | 18.3 lb |
| Refractive index | 1.46 |
| X-ray form | Amorphous |
| Assay (% SiO2) | greater than 99.8 |
| Oil adsorption | approximately 350 g/100 g oil |
| Average particle (aggregate) length | 0.2-0.3 microns |
Key Functions
- Rheology control
- Reinforcement
- Free flow
- Suspension
- Adsorbent
Applications
This fumed silica is used across a wide range of industries, including adhesives and sealants, coatings, composites, cosmetics, foods, inks, and pharmaceuticals. These applications span our adhesives and paints and coatings industry categories, where consistent rheology control from this additive supports application properties such as sag resistance, anti-settling, and thickening across the formulation.
Why Fumed Silica Rheology Control Matters
Untreated fumed silica particles carry surface silanol groups that form hydrogen bonds with each other and with polar components in a liquid system, building a loose three-dimensional network that increases viscosity at low shear and thins under mechanical agitation. This shear-thinning behavior is why this fumed silica is effective for sag resistance on vertical surfaces and anti-settling in suspensions, while still allowing the finished formulation to flow, spray, or pump normally once shear is applied. The high surface area and small aggregate size of this grade contribute to its effectiveness at relatively low loading levels compared to coarser thickening additives.
Buyers should always confirm dosage and dispersion method against the current technical data sheet, since the rheological performance of CAB-O-SIL M-5 is sensitive to how thoroughly the silica is incorporated into the base system. Common sourcing mistakes include under-shearing during dispersion or substituting a different fumed silica grade without re-validating dosage, both of which can lead to inconsistent sag resistance or anti-settling results.
Where to Source CAB-O-SIL M-5
Thousands Chemicals connects coating formulators, adhesive producers, and composite manufacturers with this fumed silica and related auxiliary agent products through our digital B2B marketplace. Our team can help confirm packaging, lead times, and technical documentation for your target application and order volume.
For buyers comparing processing additives alongside this fumed silica, our auxiliary agent product category lists additional rheology and reinforcement additives suited to coatings, adhesives, and composite formulations. Resin systems commonly formulated with fumed silica additives are available through our unsaturated polyester and vinyl ester resin category. Buyers wanting background on composite filler and additive test methodology can review the ASTM Committee D20 on Plastics resource page.
Frequently Asked Questions About CAB-O-SIL M-5
What is it used for?
It is an untreated fumed silica used for rheology control, reinforcement, free flow, suspension, and as an adsorbent across adhesives, coatings, composites, cosmetics, foods, inks, and pharmaceuticals.
What is the surface area of this fumed silica?
It has a B.E.T. surface area of 200 m²/g, with an average particle (aggregate) length of 0.2-0.3 microns.
How does CAB-O-SIL M-5 affect viscosity?
Its surface silanol groups build a loose network that increases viscosity at low shear and thins under agitation, giving sag resistance and anti-settling properties in the finished formulation.
What is the purity and pH of CAB-O-SIL M-5?
It has an assay of greater than 99.8% SiO2 and a pH of 3.7-4.3 measured as a 4% aqueous slurry.
Can you provide technical documentation and bulk pricing?
Yes, technical data sheets and SDS documentation are available on request, and our team can provide bulk pricing and lead times based on your target volume and delivery location.
Get a Quote for CAB-O-SIL M-5
Contact our team for a quote, technical data sheet, or SDS for this fumed silica. We support bulk supply and global shipping for coating formulators, adhesive producers, and composite manufacturers.
