ASTM D6845 - 12 Standard Test Method for Silica, Precipitated, Hydrated—CTAB (Cetyltrimethylammonium Bromide) Surface Area
The CTAB molecule is relatively large; so it is not adsorbed in micropores or on surface roughness. Thus, the CTAB surface area reflects only the surface of the silica that is available for interaction with rubber molecules.
1.1 This test method covers the measurement of the specific surface area of precipitated silicas exclusive of area contained in micropores too small to admit hexadecyltrimethylammonium bromide (cetyltrimethylammonium bromide, commonly referred to as CTAB) molecules. This test method is suitable for characterizing rubber-grade silicas of all types.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately)
D1193 Specification for Reagent Water
D1799 Practice for Carbon Black--Sampling Packaged Shipments
D1900 Practice for Carbon Black--Sampling Bulk Shipments
D4483 Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries
cetyltrimethylammonium bromide; CTAB; silica; surface area by CTAB method; turbidity titration; Cetyltrimethylammonium bromide (CTAB); Hydrated silica; Precipitated hydrated silica; Silica; Surface analysis--rubber chemicals/materials; Turbidity titration
ICS Number Code 71.100.55 (Silicones)
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