ASTM D6556-21

Standard Test Method for Carbon Black—Total and External Surface Area by Nitrogen Adsorption

SIGNIFICANCE AND USE
4.1 This test method is used to measure the total and external surface area of carbon blacks based on multipoint nitrogen adsorption. The NSA measurement is based on the B.E.T. theory and it includes the total surface area, inclusive of micropores, pore diameters less than 2 nm (20 Å). The external surface area, based on the statistical thickness method (STSA), is defined as the specific surface area that is accessible to rubber.  
4.2 CTAB Surface Area (formerly Test Method D3765) has been withdrawn. The CTAB value may be estimated from the STSA value using Eq 1. The equation is based on a linear regression of the STSA and CTAB measured values of the SRB 5 standards.
SCOPE
1.1 This test method covers the determination of the total surface area by the Brunauer, Emmett, and Teller (B.E.T. NSA) theory of multilayer gas adsorption behavior using multipoint determinations and the external surface area based on the statistical thickness surface area method.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (The minimum safety equipment should include protective gloves, sturdy eye and face protection).  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2021
• ICS: 71.060.10 - Chemical elements
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.21 - Carbon Black Surface Area and Related Properties

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6556 − 21
Standard Test Method for
Carbon Black—Total and External Surface Area by Nitrogen
1
Adsorption
This standard is issued under the fixed designation D6556; 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 D3765Test Method for Carbon Black—CTAB (Cetyltrim-
ethylammonium Bromide) Surface Area (Withdrawn
1.1 This test method covers the determination of the total
3
2007)
surfaceareabytheBrunauer,Emmett,andTeller(B.E.T.NSA)
D4483Practice for Evaluating Precision for Test Method
theory of multilayer gas adsorption behavior using multipoint
StandardsintheRubberandCarbonBlackManufacturing
determinations and the external surface area based on the
Industries
statistical thickness surface area method.
3. Summary of Test Method
1.2 The values stated in SI units are to be regarded as the
3.1 The total and external surface areas are measured by
standard. The values given in parentheses are for information
evaluating the amount of nitrogen adsorbed, at liquid nitrogen
only.
temperature, by a carbon black at several partial pressures of
1.3 This standard does not purport to address all of the
nitrogen. The adsorption data is used to calculate the NSAand
safety concerns, if any, associated with its use. It is the
STSA values.
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4.1 This test method is used to measure the total and
(The minimum safety equipment should include protective
external surface area of carbon blacks based on multipoint
gloves, sturdy eye and face protection).
nitrogen adsorption. The NSA measurement is based on the
B.E.T.theoryanditincludesthetotalsurfacearea,inclusiveof
1.4 This international standard was developed in accor-
micropores,porediameterslessthan2nm(20Å).Theexternal
dance with internationally recognized principles on standard-
surfacearea,basedonthestatisticalthicknessmethod(STSA),
ization established in the Decision on Principles for the
is defined as the specific surface area that is accessible to
Development of International Standards, Guides and Recom-
rubber.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 4.2 CTAB SurfaceArea (formerly Test Method D3765) has
been withdrawn. The CTAB value may be estimated from the
STSA value using Eq 1. The equation is based on a linear
2. Referenced Documents
regressionoftheSTSAandCTABmeasuredvaluesoftheSRB
2
2.1 ASTM Standards:
5 standards.
D1799 Practice for Carbon Black—Sampling Packaged
CTAB 5STSA*1.017012.6434 (1)
Shipments
D1900Practice for Carbon Black—Sampling Bulk Ship-
5. Apparatus
ments
5.1 MultipointStatic-VolumetricGasAdsorptionApparatus,
with Dewar flasks and all other accessories required for
operation.
1
This test method is under the jurisdiction ofASTM Committee D24 on Carbon
5.2 Sample Cells, that when attached to the adsorption
Black and is the direct responsibility of Subcommittee D24.21 on Carbon Black
Surface Area and Related Properties. apparatus, will maintain isolation of the sample from the
–5 3
CurrenteditionapprovedMay1,2021.PublishedJuly2021.Originallyapproved
atmosphere equivalent to a helium leak rate of <10 cm /min,
in 2000. Last previous edition approved in 2019 as D6556–19a. DOI: 10.1520/
per atmosphere of pressure difference.
D6556-21.
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
3
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D6556 − 21
5.3 Balance, Analytical, with 0.1 mg sensitivity. especially if moisture exposure has been minimal. In these
cases, the minimum time that gives a stable surface area shall
5.4 Heating Mantle or Equivalent, capable of maintaining a
be the minimum time used for degassing. It will be necessary
temperature of 300 6 10°C.
to determine these minimum times for each grade of carbon
5.5 Oven, Gravity Convection, capable of maintaining a
black.
temperature of 125 6 10°C.
8.4.4 After degassing,
...

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: D6556 − 19a D6556 − 21
Standard Test Method for
Carbon Black—Total and External Surface Area by Nitrogen
1
Adsorption
This standard is issued under the fixed designation D6556; 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 the determination of the total surface area by the Brunauer, Emmett, and Teller (B.E.T. NSA) theory
of multilayer gas adsorption behavior using multipoint determinations and the external surface area based on the statistical
thickness surface area method.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. (The minimum safety equipment should include protective gloves, sturdy eye and face
protection).
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
D1799 Practice for Carbon Black—Sampling Packaged Shipments
D1900 Practice for Carbon Black—Sampling Bulk Shipments
3
D3765 Test Method for Carbon Black—CTAB (Cetyltrimethylammonium Bromide) Surface Area (Withdrawn 2007)
D4483 Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries
3. Summary of Test Method
3.1 The total and external surface areas are measured by evaluating the amount of nitrogen adsorbed, at liquid nitrogen
temperature, by a carbon black at several partial pressures of nitrogen. The adsorption data is used to calculate the NSA and STSA
values.
4. Significance and Use
4.1 This test method is used to measure the total and external surface area of carbon blacks based on multipoint nitrogen
1
This test method is under the jurisdiction of ASTM Committee D24 on Carbon Black and is the direct responsibility of Subcommittee D24.21 on Carbon Black Surface
Area and Related Properties.
Current edition approved Dec. 15, 2019May 1, 2021. Published January 2020July 2021. Originally approved in 2000. Last previous edition approved in 2019 as
D6556 – 19.D6556 – 19a. DOI: 10.1520/D6556-19A.10.1520/D6556-21.
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.
3
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D6556 − 21
adsorption. The NSA measurement is based on the B.E.T. theory and it includes the total surface area, inclusive of micropores,
pore diameters less than 2 nm (20 Å). The external surface area, based on the statistical thickness method (STSA), is defined as
the specific surface area that is accessible to rubber.
4.2 CTAB Surface Area (formerly Test Method D3765) has been withdrawn. The CTAB value may be estimated from the STSA
value using Eq 1. The equation is based on a linear regression of the STSA and CTAB measured values of the SRB 5 standards.
CTAB 5 STSA*1.017012.6434 (1)
5. Apparatus
5.1 Multipoint Static-Volumetric Gas Adsorption Apparatus, with Dewar flasks and all other accessories required for operation.
5.2 Sample Cells, that when attached to the adsorption apparatus, will maintain isolation of the sample from the atmosphere
–5 3
equivalent to a helium leak rate of <10 cm /min, per atmosphere of pressure difference.
5.3 Balance, Analytical, with 0.1 mg sensitivity.
5.4 Heating Mantle or Equivalent, capable of maintaining a temperature of 300 6 10°C.
5.5 Oven, Gravity Convection, capable of maintaining a temperature of 125 6 10°C.
6. Reagents
6.1 L
...