ASTM D3849-14

Standard Test Method for Carbon Black—Morphological Characterization of Carbon Black Using Electron Microscopy

SIGNIFICANCE AND USE
4.1 Carbon black morphology significantly affects the transient and end-use properties of carbon black loaded polymer systems. A carbon black's particle size distribution is its single most important property, and it relates to degree of blackness, rubber reinforcement, and ability to impart UV protection. For a given loading of carbon black, blackness, reinforcement, and UV protection increase with smaller particle size. Aggregate size and shape (structure) also affect a carbon black's 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 carbon black morphology (for example, size and shape) is transmission electron microscopy (TEM), but due to the semi-quantitative nature of TEM, it is not suited for mean particle size (MPS) certification.  
4.2 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.
SCOPE
1.1 This test method covers (1) the morphological (for example, size and shape) characterization of carbon black from transmission electron microscope images which 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 and (2) the certification of mean particle size using a correlation based on statistical thickness surface area measurements.  
1.2 The values stated in SI units are to be regarded as the standard. The values 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2013
• ICS: 83.040.20 - Rubber compounding ingredients
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.81 - Carbon Black Microscopy and Morphology

Relations

• Replaces: ASTM D3849-13 - Standard Test Method for Carbon Black—Morphological Characterization of Carbon Black Using Electron Microscopy
• Effective Date: 01-Jan-2014
• Referred By: ASTM D3053-23 - Standard Terminology Relating to Carbon Black
• Effective Date: 01-Jan-2014
• Referred By: ASTM D8466-22 - Standard Guide for Recovered Carbon Black—Carbon Black Test Methods for Testing rCB
• Effective Date: 01-Jan-2014
• Referred By: ASTM D6602-13(2022)e1 - Standard Practice for Sampling and Testing of Possible Carbon Black Fugitive Emissions or Other Environmental Particulate, or Both
• Effective Date: 01-Jan-2014

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D3849 − 14
StandardTest Method for
Carbon Black—Morphological Characterization of Carbon
1
Black Using Electron Microscopy
This standard is issued under the fixed designation D3849; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1.2 carbon black aggregate—a discrete, rigid colloidal
entity that is the smallest dispersible unit; it is composed of
1.1 This test method covers (1) the morphological (for
extensively coalesced particles; carbon black aggregate size is
example,sizeandshape)characterizationofcarbonblackfrom
a distributional property; therefore, the term aggregate size
transmission electron microscope images which are used to
implies the mean value from multiple measurements.
derive the mean particle and aggregate size of carbon black in
the dry (as manufactured) state, from CAB chip dispersion or 3.1.1.3 statistical thickness surface area (STSA)—the exter-
removed from a rubber compound and (2) the certification of nalspecificsurfaceareaofcarbonblackthatiscalculatedfrom
mean particle size using a correlation based on statistical nitrogenadsorptiondatausingthedeBoertheoryandacarbon
thickness surface area measurements. black-specific model.
1.2 The values stated in SI units are to be regarded as the 3.1.1.4 glow discharge—a plasma of ionized gas that is
standard. The values in parentheses are for information only. formed in a high-voltage field at pressures of about 3 to 20 Pa
-3
(25 to 150 × 10 torr); an alternating current (a-c) glow
1.3 This standard does not purport to address all of the
discharge using air is effective in cleaning and oxidizing the
safety concerns, if any, associated with its use. It is the
surface of carbon substrates to improve the wetting character-
responsibility of the user of this standard to establish appro-
istics of polar vehicles containing pigment dispersions.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3.1.1.5 substrate—athinfilmthatisusedtosupportelectron
microscopespecimens;evaporatedcarbonfilmsarecommonly
2. Referenced Documents
used because of relatively good mechanical strength, stability,
2
and conductivity.
2.1 ASTM Standards:
D6556Test Method for Carbon Black—Total and External
3.1.2 Aggregate Dimensional Properties from Image Analy-
Surface Area by Nitrogen Adsorption
sis:
3.1.2.1 area (A)—the two-dimensional projected area of the
3. Terminology
carbon black aggregate image.
3.1 Definitions:
3.1.2.2 perimeter (P)—the total boundary length of an
3.1.1 General:
aggregate.
3.1.1.1 carbon black particle—a small spheroidally shaped,
3.1.2.3 volume (V)—anestimateofthevolumeofthecarbon
paracrystalline,non-discretecomponentofanaggregate;itcan
black aggregate using stereological principles.
only be separated from the aggregate by fracturing; carbon
3.1.3 Image Analysis:
black particle size is a distributional property; therefore, the
3.1.3.1 dilation—the converse of erosion; this process is
term particle size implies the mean value from multiple
accomplished by changing any OFF pixel to ON if it has
measurements.
greaterthanapresetminimumofONneighbors,causingimage
features to grow in size, which fills in small breaks in features,
internal voids, or small indentations along the feature surface.
1
This test method is under the jurisdiction ofASTM Committee D24 on Carbon
Black and is the direct responsibility of Subcommittee D24.81 on Carbon Black
3.1.3.2 erosion—the process by which image features are
Microscopy and Morphology.
reduced in size by selectively removing pixels from their
Current edition approved Jan. 1, 2014. Published January 2014. Originally
periphery; it consists of examining each binary pixel and
approved in 1980. Last previous edition approved in 2013 as D3849–13. DOI:
10.1520/D3849-14.
changing it from ON to OFF if it has greater than a preset
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
minimum of neighbors that are OFF; it serves a number of
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
useful functions, such as smoothing feature outlines and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. separating features touching each other.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D3849 − 14
3.1.3.3 feature—areas within a single continuous boundary 6.2 Image Analysis System, consisting at minimum of a
that have gray-level ranges tha
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3849 − 13 D3849 − 14
Standard Test Method for
Carbon Black—Morphological Characterization of Carbon
1
Black Using Electron Microscopy
This standard is issued under the fixed designation D3849; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers (1) the morphological (for example, size and shape) characterization of carbon black from
transmission electron microscope images which 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 and (2) the certification of mean particle
size using a correlation based on statistical thickness surface area measurements.
1.2 The values stated in SI units are to be regarded as the standard. The values 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
2
2.1 ASTM Standards:
D6556 Test Method for Carbon Black—Total and External Surface Area by Nitrogen Adsorption
3. Terminology
3.1 Definitions:
3.1.1 General:
3.1.1.1 carbon black particle—a small spheroidally shaped, paracrystalline, non-discrete component of an aggregate; it can only
be separated from the aggregate by fracturing; carbon black particle size is a distributional property; therefore, the term particle
size implies the mean value from multiple measurements.
3.1.1.2 carbon black aggregate—a discrete, rigid colloidal entity that is the smallest dispersible unit; it is composed of
extensively coalesced particles; carbon black aggregate size is a distributional property; therefore, the term aggregate size implies
the mean value from multiple measurements.
3.1.1.3 statistical thickness surface area (STSA)—the external specific surface area of carbon black that is calculated from
nitrogen adsorption data using the de Boer theory and a carbon black-specific model.
3.1.1.4 glow discharge—a plasma of ionized gas that is formed in a high-voltage field at pressures of about 3 to 20 Pa (25 to
-3
150 × 10 torr); an alternating current (a-c) glow discharge using air is effective in cleaning and oxidizing the surface of carbon
substrates to improve the wetting characteristics of polar vehicles containing pigment dispersions.
3.1.1.5 substrate—a thin film that is used to support electron microscope specimens; evaporated carbon films are commonly
used because of relatively good mechanical strength, stability, and conductivity.
3.1.2 Aggregate Dimensional Properties from Image Analysis:
3.1.2.1 area (A)—the two-dimensional projected area of the carbon black aggregate image.
3.1.2.2 perimeter (P)—the total boundary length of an aggregate.
3.1.2.3 volume (V)—an estimate of the volume of the carbon black aggregate using stereological principles.
1
This test method is under the jurisdiction of ASTM Committee D24 on Carbon Black and is the direct responsibility of Subcommittee D24.81 on Carbon Black
Microscopy and Morphology.
Current edition approved Oct. 1, 2013Jan. 1, 2014. Published October 2013January 2014. Originally approved in 1980. Last previous edition approved in 20112013 as
D3849 – 07 (2011).D3849 – 13. DOI: 10.1520/D3849-13.10.1520/D3849-14.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D3849 − 14
3.1.3 Image Analysis:
3.1.3.1 dilation—the converse of erosion; this process is accomplished by changing any OFF pixel to ON if it has greater than
a preset minimum of ON neighbors, causing image features to grow in size, which fills in small breaks in features, internal voids,
or small indentations along the feature surface.
3.1.3.2 erosion—the process by which image features are reduced in size by selectively removing pixels from their
...