ASTM D8036-16

Standard Test Method for Polyurethane Raw Materials: Determination of Dimer Ratio in Pure MDI

SIGNIFICANCE AND USE
5.1 This test method can be used for research or for quality control to determine the dimer ratio of Pure MDI.  
5.2 Uretidinedione begins forming in Pure MDI with the rate of formation increasing with increasing temperature. High levels can affect the appearance of Pure MDI and the quality of products made from it.
SCOPE
1.1 This test method determines the ratio of the infrared absorbance of uretidinedione (dimer) in methylene-4,4’- di(phenylisocyanate) to an infrared absorbance at a reference wavelength within the same material. It is applicable to monomeric methylene-di(phenylisocyanate), or “Pure MDI,” containing 95 % or greater methylene-4,4’-di(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.
Note 1: There is no known ISO equivalent to this standard.

General Information

• Status: Published
• Publication Date: 30-Apr-2016
• ICS: 83.040.10 - Latex and raw rubber
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.22 - Cellular Materials - Plastics and Elastomers

Relations

• Refers: ASTM D883-17 - Standard Terminology Relating to Plastics
• Effective Date: 15-Aug-2017
• Refers: ASTM D883-18 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2018
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020

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: D8036 − 16
Standard Test Method for
Polyurethane Raw Materials: Determination of Dimer Ratio
1
in Pure MDI
This standard is issued under the fixed designation D8036; 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 absorbance ratio of the peak maximum at approximately 1778
–1
cm , corresponding to the carbonyls present in uretidinedione,
1.1 This test method determines the ratio of the infrared
to the para-substituted ring combination peak maximum at
absorbance of uretidinedione (dimer) in methylene-4,4’- di-
–1
approximately 1900 cm is calculated.
(phenylisocyanate) to an infrared absorbance at a reference
wavelength within the same material. It is applicable to
5. Significance and Use
monomeric methylene-di(phenylisocyanate), or “Pure MDI,”
containing 95 % or greater methylene-4,4’- 5.1 This test method can be used for research or for quality
di(phenylisocyanate).
control to determine the dimer ratio of Pure MDI.
1.2 This standard does not purport to address all of the
5.2 Uretidinedione begins forming in Pure MDI with the
safety concerns, if any, associated with its use. It is the
rate of formation increasing with increasing temperature. High
responsibility of the user of this standard to establish appro-
levels can affect the appearance of Pure MDI and the quality of
priate safety and health practices and determine the applica-
products made from it.
bility of regulatory limitations prior to use.
6. Apparatus
NOTE 1—There is no known ISO equivalent to this standard.
6.1 Spectrometer—A Fourier-Transform infrared spectrom-
2. Referenced Documents
eter accurate to 0.2 % transmission and capable of resolving
2 –1
2.1 ASTM Standards: the dimer peak maximum at approximately 1778 cm and
–1
D883 Terminology Relating to Plastics reference peak maximum at approximately 1900 cm .
E691 Practice for Conducting an Interlaboratory Study to
6.2 Cell, sealed sodium chloride (NaCl) liquid absorption
Determine the Precision of a Test Method
cell with 0.5-mm path length.
6.3 Glassware, 25-mL, glass-stoppered, volumetric flask
3. Terminology
and an all-glass syringe.
3.1 Terminology in this test method is in accordance with
Terminology D883.
7. Reagents and Materials
3.2 Definitions of Terms Specific to This Standard:
7.1 Purity of Reagents—Use reagent grade chemicals in all
3.2.1 dimer, n—uretidinedione, with the structure in Fig. 1,
tests. Unless otherwise noted, all reagents conform to the
is an undesirable reaction product of two or more isocyanate
specifications of the Committee on Analytical Reagents of the
groups.
American Chemical Society where such specifications are
3
available. It is acceptable to use other grades, provided it is
4. Summary of Test Method
ascertained that the reagent is of sufficiently high purity to
4.1 The infrared spectrum of a dichloromethane solution of
permit its use without lessening the accuracy of the determi-
–1
the sample is recorded in the 1600 to 2000 cm region. The
nation.
7.2 Dichloromethane, reagent grade.
1
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.22 on Cellular Materials -
Plastics and Elastomers.
3
Current edition approved May 1, 2016. Published May 2016. DOI: 10.1520/ Reagent Chemicals, American Chemical Society Specifications, American
D8036-16. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
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1

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D8036 − 16
FIG. 1 Dimer Structure
8. Sampling 11. Procedure
8.1 Since organic isocyanates react with atmospheric
11.1 Scan an open-path background (the light path clear of
–1
moisture, take special precautions in sampling. Usual sampling
any cell). Use a resolution of 4 cm or better and take at least
methods, even when conducted rapidly, can caus
...