ASTM D4671-05

Standard Test Method for Polyurethane Raw Materials Determination of Unsaturation of Polyols

SIGNIFICANCE AND USE
These test methods are suitable for quality control, as specification tests, and for research.
Side reactions that form unsaturated compounds in polypropylene oxides produce small amounts of polymers with only one hydroxyl group per chain. These unsaturated polymers lower functionality and molecular weight, while broadening the overall molecular-weight distribution.
SCOPE
1.1 These test methods measure unsaturation in polyether polyols. (See Note 0.)
1.1.1 Test Method A, High-Volume Reagent MethodUses about 50 mL of 0.1 M mercuric acetate reagent in methanol and 15 g or more of sample. These test methods use an indicator for colorimetric determination of an end point. It is recommended for polyols with low values (below 0.01 millequivalents per gram (meq/g)) of unsaturation where large sample sizes are required.
1.1.2 Test Method B, Low-Volume Reagent MethodUses 2 mL of ca. 0.05 M mercuric acetate reagent in methanol and about 1 g of sample or less. These test methods use a potentiometric determination of an end point.
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 0
There is no equivalent ISO standard.

General Information

• Status: Historical
• Publication Date: 28-Feb-2005
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.22 - Cellular Materials - Plastics and Elastomers

Relations

• Replaces: ASTM D4671-99 - Standard Test Method for Polyurethane Raw Materials Determination of Unsaturation of Polyols
• Effective Date: 01-Mar-2005
• Replaced By: ASTM D4671-05(2010)e1 - Standard Test Method for Polyurethane Raw Materials Determination of Unsaturation of Polyols
• Effective Date: 01-Jul-2010

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D4671–05
Standard Test Methods for
Polyurethane Raw Materials: Determination of Unsaturation
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of Polyols
This standard is issued under the fixed designation D4671; 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* 4. Summary of Test Method
1.1 These test methods measure unsaturation in polyether 4.1 Carbon-to-carbon unsaturated compounds in the sample
polyols. (See Note 1.) are reacted with mercuric acetate and methanol in a methanolic
1.1.1 Test Method A, High-Volume Reagent Method—Uses solution to produce acetoxymercuricmethoxy compounds and
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about50mLof0.1 Mmercuricacetatereagentinmethanoland acetic acid. The amount of acetic acid released in this
15gormoreofsample.Thesetestmethodsuseanindicatorfor equimolar reaction, which is determined by titration with
colorimetric determination of an end point. It is recommended standard alcoholic potassium hydroxide, is a measure of the
for polyols with low values (below 0.01 millequivalents per unsaturation originally present. Because the acid cannot be
gram (meq/g)) of unsaturation where large sample sizes are titrated in the presence of excess mercuric acetate, due to the
required. formation of insoluble mercuric oxide, sodium bromide is
1.1.2 Test Method B, Low-Volume Reagent Method—Uses 2 added to convert the mercuric acetate to the bromide, which
mL of ca. 0.05 M mercuric acetate reagent in methanol and does not interfere. Inasmuch as these test methods are based on
about1gof sample or less. These test methods use a an acidimetric titration, a suitable correction must be applied if
potentiometric determination of an end point. the sample is not neutral to phenolphthalein indicator. Take
1.2 This standard does not purport to address all of the care to exclude carbon dioxide, which titrates as an acid and
safety concerns, if any, associated with its use. It is the gives erroneous results.
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety and health practices and determine the applica-
5.1 These test methods are suitable for quality control, as
bility of regulatory limitations prior to use.
specification tests, and for research.
NOTE 1—There is no equivalent ISO standard.
5.2 Side reactions that form unsaturated compounds in
polypropylene oxides produce small amounts of polymers with
2. Referenced Documents
only one hydroxyl group per chain. These unsaturated poly-
2
2.1 ASTM Standards:
mers lower functionality and molecular weight, while broad-
D883 Terminology Relating to Plastics
ening the overall molecular-weight distribution.
E180 Practice for Determining the Precision of ASTM
Methods for Analysis and Testing of Industrial and Spe-
6. Interferences
cialty Chemicals
6.1 These test methods do not apply to compounds in which
the unsaturation is conjugated with carbonyl, carboxyl, or
3. Terminology
nitrile groups. Because water presumably hydrolyzes the reac-
3.1 Definitions—For definitions of terms used in these test
tion products to form basic mercuric salts, quantitative results
methods, see Terminology D883.
are obtained only when the system is essentially anhydrous.
Acetone in low concentrations does not interfere significantly,
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These test methods are under the jurisdiction of ASTM Committee D20 on
although its presence can be detrimental to the end point.
Plastics and are the direct responsibility of Subcommittee D20.22 on Cellular
Inorganic salts, especially halides, must be absent from the
Materials - Plastics and Elastomers. Test MethodAwas recommended toASTM by
sample because even small amounts of salts can nullify the
the Society of the Plastics Industry Polyurethane Raw Materials Analysis Commit-
reaction of the mercuric acetate with the unsaturated com-
tee.
Current edition approved March 1, 2005. Published March 2005. Originally
pound.
approved in 1987. Last previous edition approved in 1999 as D4671 - 99. DOI:
10.1520/D4671-05.
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
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Standards volume information, refer to the standard’s Document Summary page on Sigia, S. and Hanna, J.G., “Quantitative Organic Analysis via Functional
the ASTM website. Groups,” John Wiley and Sons, New York, 1979.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D4671–05
TEST METHOD A—HIGH-VOLUME REAGENT
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