ASTM D4527-18(2023)

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: D4527 − 18 (Reapproved 2023)
Standard Test Method for
Carbon Black—Solvent Extractables
This standard is issued under the fixed designation D4527; 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 3. Summary of Test Method
3.1 A specimen of carbon black is extracted for 48 h (or
1.1 This test method covers the procedure for measuring
other specified time) in a Soxhlet extractor, the solvent re-
carbon black solvent extractables.
moved by controlled temperature evaporation, and the ex-
1.1.1 This test method determines the total material ex-
tracted residue determined gravimetrically. If the carbon black
tracted from carbon black by toluene under specified condi-
extractables are to be subjected to additional analysis, see
tions. The procedure is also applicable to other solvents such as
Section 7.
cyclohexane, etc.
1.2 The values stated in SI units are to be regarded as 4. Significance and Use
standard. No other units of measurement are included in this
4.1 The carbon black extract test procedure provides a
standard.
uniform and precise method for the gravimetric determination
of organic-solvent extractables on carbon black. Accuracy and
1.3 This standard does not purport to address all of the
precision are acceptable for most specification or regulatory
safety concerns, if any, associated with its use. It is the
purposes, or both. However, carbon black with very low extract
responsibility of the user of this standard to establish appro-
(less than 0.02 %) may require a more rigorous extraction
priate safety, health, and environmental practices and deter-
procedure. The actual chemical composition of the extract can
mine the applicability of regulatory limitations prior to use.
vary significantly with the type and origin of the carbon black.
For a specific precautionary statement, see Section 7.
1.4 This international standard was developed in accor-
5. Apparatus
dance with internationally recognized principles on standard-
5.1 Soxhlet Extraction Apparatus, with interchangeable
ization established in the Decision on Principles for the
3 3
ground joints, 40 mm I.D. extraction tube, and 250-cm flask.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5.2 Extraction Thimble, glass, 35-mm diameter by 90-mm
Barriers to Trade (TBT) Committee.
height, with coarse porosity fritted disc. When filled with 50
3 3
cm of toluene, drainage time for the first 40 cm should not
2. Referenced Documents
exceed 95 s. Discard thimbles taking longer.
5.3 Heater, for extraction flask, with adjustable heat input. A
2.1 ASTM Standards:
D4483 Practice for Evaluating Precision for Test Method hot plate extraction heater or hemispherical heating mantle is
preferred.
Standards in the Rubber and Carbon Black Manufacturing
Industries
5.4 Filter Funnel, glass fritted disc type, with medium
porosity fritted disc.
5.5 Filter Flask, 125 or 250 cm .
This test method is under the jurisdiction of ASTM Committee D24 on Carbon
Black and is the direct responsibility of Subcommittee D24.31 on Non-Carbon
Black Components of Carbon Black.
Current edition approved Jan. 1, 2023. Published February 2023. Originally Fisher Scientific No. 9-556B available from Fisher Scientific Co., 203 Fisher
approved in 1985. Last previous edition approved in 2018 as D4527 – 18. DOI: Ave., Pittsburgh, PA 15219, has been found satisfactory. The use of Kontas
10.1520/D4527-18R23. K-586100 (glass jacketed) available from Kontas Glass Co., 8000 Spruce St.,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Vineland, NJ 08360, simplifies insulating the apparatus and reduces the possibility
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM of breakage.
Standards volume information, refer to the standard’s Document Summary page on Fisher Scientific 9-653B available from Fisher Scientific Co., has been found
the ASTM website. satisfactory.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4527 − 18 (2023)
5.6 Water Bath, or other suitable warming means for evapo- fritted disc becomes fouled with carbon black, it may be
rating solvent from extract at a controlled temperature of 40 to necessary to burn it out by slowly heating the thimble from
50°C. room temperature to 500°C in a muffle furnace. One hour is
usually sufficient. The use of chromic acid cleaning solution is
5.7 Container, suitable for final solvent removal and weigh-
not recommended. The permeability of the clean thimble
ing of residue. A lightweight aluminum dish 63 by 17.5 mm, a
3 5 should be checked periodically. Discard thimbles with drainage
TFE-fluorocarbon cup or a 50-cm glass beaker is suggested.
times exceeding the 95 s specified under 5.2.
5.8 Vacuum Oven, gravity-convection type, capable of tem-
7.5 To prevent contamination, it is recommended that all
perature regulation within 61°C at 125°C and temperature
glassware used in this procedure be reserved for the extraction
uniformity within 65°C.
of carbon black. If this is not feasible, the glassware must be
5.9 Oven, gravity-convection type, capable of temperature
extracted before use in accordance with 7.6.
regulation within 61°C at 125°C and temperature uniformity
7.6 New glassware, including thimbles, must be extracted,
within 65°C.
repeatedly if necessary, with toluene or other solvent until the
5.10 Desiccator. 3
blank is acceptable (preferably less than 0.3 mg/150 cm
solvent).
5.11 Analytical Balance, with a sensitivity of 60.1 mg.
7.7 Two or three glass beads may be added to the extraction
6. Reagents and Materials
flask to promote smooth boiling. Do not use porous boiling
6.1 Toluene, having a residue after evaporation less than 10
chips.
ppm (preferably less than 2 ppm).
7.8 An extraction must be discarded if there is any visible
6.2 Nitrogen.
carbon black in the extraction flask or if the thimble does not
drain properly and overflows at any time during the extraction.
6.3 Glass wool, extracted with toluene, air-dried, followed
by drying in a convection oven at 125°C for 1 h. Store in a
7.9 The nitrogen should be delivered through a glass or
closed container until ready to use.
metal tip. Do not allow plastic or rubber to contact the solvent.
6.4 Aluminum Foil.
7.10 To protect from dust, a loose cover over the evapora-
tion vessel is recommended.
7. Precautions
7.11 Solvent evaporation may be conducted in a vacuum
7.1 For safety reasons, conduct the extraction and solvent
evaporator, if available.
evaporation in an approved fume hood. Carbon blacks may
7.12 Any further analysis of the extracted material typically
contain polynuclear aromatic compounds, some of which are
requires that it be in solution. Complete re-solution of the dry
carcinogens. These compounds, when present, are so strongly
extract may be difficult or impossible. Therefore, if further
bound to the carbon black that they are biologically inactive.
analysis is to be performed, an additional sample of the carbon
However, they may be removed by extraction with toluene or
black should be extracted and solvent removal carried only to
other appropriate solvents. Avoid skin contact with solvent
the desired reduced volume. It is recommended that exposure
extracts from such carbon blacks.
to strong light, especially sunlight, be avoided during extrac-
7.2 For most pelleted blacks, the depth of 60 mm in the
tion and subsequent handling, and that the extract be blanketed
thimble should provide a sample of 15 to 25 g. Unpelleted
with inert gas (nitrogen) if retained for any length of time.
blacks should be predensified sufficiently that this depth will
7.13 It has been found that there may be significant varia-
require a sample of at least 10 g.
tion in the amount of residue found in different bottles of
7.3 Do not use joint lubricant on the ground joints. To
toluene bearing the same lot number. Consequently, blanks
minimize vapor loss by leakage, the joints may be sealed with
should be run on each bottle.
TFE-fluorocarbon inserts or wrapped with TFE-fluorocarbon
laboratory tape.
8. Procedure
7.4 New thimbles should be washed before use by suction
8.1 Dry an adequate specimen of the carbon black for 1 h in
with hot HCl and then rinsed with distilled or deionized water
the gravity-convection oven set at 125°C in an open container
to remove loose particles of foreign matter such as dust.
of suitable dimensions
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