ASTM D5155-07

Standard Test Methods for Polyurethane Raw Materials Determination of the Isocyanate Content of Aromatic Isocyanates

SIGNIFICANCE AND USE
These test methods can be used for research or for quality control to characterize isocyanates used in polyurethane products.
SCOPE
1.1 These test methods measure the isocyanate content of aromatic isocyanates used as polyurethane raw materials.
1.1.1 Test Method A—Unheated toluene-dibutylamine determines the amount of toluene diisocyanate in refined toluene-2,4-diisocyanate and toluene-2,6-diisocyanate, or mixtures of the two. Other isomers, if present, will be included in the determination. This test method may also be applied to other isocyanates of suitable reactivity and solubility.
1.1.2 Test Method B—Heated toluene-dibutylamine determines the amine equivalent of crude or modified isocyanates derived from toluene diisocyanate, methylenebis-(4-phenylisocyanate), and polymethylene polyphenylisocyanate.
1.1.3 Test Method C—Unheated trichlorobenzene-toluene-dibutylamine determines the isocyanate content of crude or modified isocyanates derived from toluene diisocyanate, methylene-bis-(4-phenylisocyanate), and polymethylene polyphenylisocyanate. This test method can also be used to assay isomer mixtures of toluene diisocyanate and methylene-bis-(phenylisocyanate).
1.2 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. For specific warning and precautionary statements, see Note 2.
Note 1—Method C of this test method is equivalent to Method B of ISO 14896.

General Information

• Status: Historical
• Publication Date: 31-Mar-2007
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.22 - Cellular Materials - Plastics and Elastomers

Relations

• Replaces: ASTM D5155-01 - Standard Test Methods for Polyurethane Raw Materials Determination of the Isocyanate Content of Aromatic Isocyanates
• Effective Date: 01-Apr-2007
• Replaced By: ASTM D5155-10 - Standard Test Methods for Polyurethane Raw Materials Determination of the Isocyanate Content of Aromatic Isocyanates
• Effective Date: 01-Apr-2010
• Referred By: ASTM D1786-21 - Standard Specification for Toluene Diisocyanate
• Effective Date: 01-Apr-2007

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:D5155–07
Standard Test Methods for
Polyurethane Raw Materials: Determination of the
1
Isocyanate Content of Aromatic Isocyanates
This standard is issued under the fixed designation D5155; 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* D1193 Specification for Reagent Water
E180 Practice for Determining the Precision of ASTM
1.1 These test methods measure the isocyanate content of
Methods for Analysis and Testing of Industrial and Spe-
aromatic isocyanates used as polyurethane raw materials.
cialty Chemicals
1.1.1 Test Method A—Unheated toluene-dibutylamine de-
2.2 ISO Standard:
terminestheamountoftoluenediisocyanateinrefinedtoluene-
ISO14896 Polyurethane Raw Materials-Determination of
2,4-diisocyanate and toluene-2,6-diisocyanate, or mixtures of
Isocyanate Content
the two. Other isomers, if present, will be included in the
determination. This test method may also be applied to other
3. Terminology
isocyanates of suitable reactivity and solubility.
3.1 Definitions:
1.1.2 Test Method B—Heated toluene-dibutylamine deter-
3.1.1 polyurethane—a polymer prepared by the reaction of
mines the amine equivalent of crude or modified isocyanates
an organic diisocyanate or polyisocyanate with compounds
derived from toluene diisocyanate, methylenebis-(4-
containing hydroxyl groups.
phenylisocyanate), and polymethylene polyphenylisocyanate.
3.1.1.1 Discussion—Polyurethanesorurethanes,astheyare
1.1.3 Test Method C—Unheated trichlorobenzene-toluene-
sometimes called, may be thermosetting, thermoplastic, rigid
dibutylamine determines the isocyanate content of crude or
or soft and flexible, or cellular or solid (see Terminology
modified isocyanates derived from toluene diisocyanate,
D883).
methylene-bis-(4-phenylisocyanate), and polymethylene
3.2 Definitions of Terms Specific to This Standard:
polyphenylisocyanate. This test method can also be used to
3.2.1 amine equivalent—the weight of sample that will
assay isomer mixtures of toluene diisocyanate and methylene-
combine with 1.0-g equivalent weight of dibutylamine.
bis-(phenylisocyanate).
3.2.2 assay—the percent by weight of toluene diisocyanate
1.2 This standard does not purport to address all of the
present in the sample.
safety concerns, if any, associated with its use. It is the
3.2.3 isocyanate (NCO) content—the weight percent of the
responsibility of the user of this standard to establish appro-
NCO groups present in the sample.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. For specific
4. Summary of Test Methods
warning and precautionary statements, see Note 2.
4.1 All three test methods react the isocyanate sample with
NOTE 1—Method C of this test method is equivalent to Method B of
an excess of dibutylamine to form the corresponding urea.The
ISO14896.
NCO content is determined from the amount of dibutylamine
consumed in the reaction. Each test method varies solvent or
2. Referenced Documents
heating times to yield accurate assays of the sample in
2
2.1 ASTM Standards:
question.
D883 Terminology Relating to Plastics
4.1.1 Test Method A—The sample is added to an excess of
dibutylamineintolueneandallowedtostandatroomtempera-
1
These test methods are under the jurisdiction of ASTM Committee D20 on
ture for 15 min. The reaction mixture is diluted with isopropyl
Plastics and are the direct responsibility of Subcommittee D20.22 on Cellular
alcohol, and the excess dibutylamine is back-titrated with
Materials - Plastics and Elastomers. These test methods were recommended to
hydrochloric acid.
ASTMbytheSocietyofthePlasticsIndustryPolyurethaneRawMaterialsAnalysis
Committee.
4.1.2 Test Method B—The sample is added to an excess of
Current edition approved April 1, 2007. Published April 2007. Originally
dibutylamine in toluene and stirred for 20 min. The resulting
approved in 1991. Last previous edition approved in 2001 as D5155-01. DOI:
solution is then heated rapidly to 100°C, removed from the
10.1520/D5155-07.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or heat, and allowed to stand for 30 min. The reaction mixture is
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
diluted with isopropyl alcohol, and the excess dibutylamine is
Standards volume information, refer to the standard’s Document Summary page on
back-titrated with hydrochloric acid.
the ASTM website.
*A Summary of Changes section appears at the end of this standard.
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