ASTM D3849-07

Carbon black morphology significantly affects the transient and end-use properties of carbon black loaded polymer systems. A carbon black’particle size distribution is its single most important property, and it relates to degree of blackness and rubber reinforcement. For a given loading of carbon black, blackness and reinforcement increase with smaller particle size. Aggregate size and shape (structure) also affect a carbon black’end-use performance, as higher carbon black structure increases viscosity and improves dispersion. The stiffness (modulus) of elastomer systems becomes significantly higher with increasing structure. The preferred method for measuring these properties is transmission electron microscopy.

Carbon black aggregate dimensional and shape properties are dependent upon the nature of the system in which the sample is dispersed, as well as the mixing procedure.

1.1 This test method covers the morphological characterization of carbon black primary aggregates from transmission electron microscope images. These measurements are used to derive the mean particle and aggregate size of carbon black in the dry (as manufactured) state, from CAB chip dispersion or removed from a rubber compound.

1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

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.