ASTM D4663-98

Standard Test Method for Polyurethane Raw Materials Determination of Hydrolyzable Chlorine of Isocyanates

SCOPE
1.1 This test method determines the hydrolyzable chlorine content of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, or mixtures of the two. This test method may also be applied to other isocyanates of suitable solubility. (See Note 1.) The main sources of hydrolyzable chlorine in the isocyanates are carbamoyl chloride and dissolved phosgene. Both of these compounds react with alcohols and water, forming ureas, carbamates, carbon dioxide, and hydrochloric acid. (See Note 2.)  
1.2 This standard does not purport to address all of the safety problems, 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 hazards statements see Note 3.  Note 1-This test method may be applicable with crude polymeric isocyanates. However, the precision with crude polymeric isocyanates has not been established. Note 2-There is no equivalent ISO standard.

General Information

• Status: Historical
• Publication Date: 09-Jul-1998
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.22 - Cellular Materials - Plastics and Elastomers

Relations

• Replaced By: ASTM D4663-98(2004) - Standard Test Method for Polyurethane Raw Materials Determination of Hydrolyzable Chlorine of Isocyanates
• Effective Date: 01-Mar-2004
• Referred By: ASTM D1786-21 - Standard Specification for Toluene Diisocyanate
• Effective Date: 10-Jul-1998
• Referred By: ASTM D4661-23 - Standard Test Methods for Polyurethane Raw Materials: Determination of Total Chlorine in Isocyanates
• Effective Date: 10-Jul-1998

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 4663 – 98
Standard Test Method for
Polyurethane Raw Materials: Determination of Hydrolyzable
Chlorine of Isocyanates
This standard is issued under the fixed designation D 4663; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.1 hydrolyzable chloride—the low level chlorine-
containing components of the isocyanate, such as carbamoyl
1.1 This test method determines the hydrolyzable chlorine
chlorides, which react with water or alcohol to form HCl.
content of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate,
or mixtures of the two. This test method may also be applied to
4. Summary of Test Method
other isocyanates of suitable solubility. (See Note 1.) The main
4.1 The hydrolyzable chlorine reacts with methanol, liber-
sources of hydrolyzable chlorine in the isocyanates are car-
ating hydrochloric acid. The titratable chlorides are then
bamoyl chloride and dissolved phosgene. Both of these com-
determined potentiometrically using a standard silver nitrate
pounds react with alcohols and water, forming ureas, carbam-
solution.
ates, carbon dioxide, and hydrochloric acid. (See Note 2.)
1.2 This standard does not purport to address all of the
5. Significance and Use
safety concerns, if any, associated with its use. It is the
5.1 This test method can be used for research or for quality
responsibility of the user of this standard to establish appro-
control to characterize toluene diisocyanates. Hydrolyzable
priate safety and health practices and determine the applica-
chlorine correlates with performance in some polyurethane
bility of regulatory limitations prior to use. For specific hazards
systems.
statements see Note 3.
6. Interferences
NOTE 1—This test method may be applicable with crude polymeric
isocyanates. However, the precision with crude polymeric isocyanates has
6.1 Thiocyanate, cyanide, sulfide, bromide, iodide, or other
not been established.
substances capable of reacting with silver ion, as well as
NOTE 2—There is no equivalent ISO standard.
substances capable of reducing silver ion in acid solution, will
interfere with the determination.
2. Referenced Document
2.1 ASTM Standards:
7. Apparatus
D 883 Terminology Relating to Plastics
7.1 Weighing Bottle, or any device capable of weighing a
D 1193 Specification for Reagent Water
liquid by difference to the nearest 0.1 g.
7.2 Hot Plate, with magnetic stirrer.
3. Terminology
7.3 Potentiometric Titrator, or pH meter.
3.1 Definitions—For definitions of terms used in this test
7.4 Silver-Silver Chloride Electrode.
method see Terminology D 883.
7.5 Silver or Glass Electrode.
3.2 Description of Term Specific to This Standard.
7.6 Calomel Electrode.
8. Reagents and Materials
This test method is under the jurisdiction of ASTM Committee D-20 on
Plastics and is the direct responsibility of Subcommittee D20.22 on Cellular
8.1 Purity of Reagents—Use reagent grade chemicals in all
Plastics.
tests. Unless otherwise indicated, it is intended that all reagents
Current edition approved July 10, 1998. Published September 1998. Originally
conform to the specifications of the Committee on Analytical
published as D 4663 – 87. Last previous edition D 4663 – 93.
Annual Book of ASTM Standards, Vol 08.01. Reagents of the American Chemical Society where such
Annual Book of ASTM Standards, Vol 11.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4663
NOTE 5—Some isocyanates will not react readily and slight warming
specifications are available. Other grades may be used, pro-
may be necessary to initiate reaction. Other isocyanates may react, as
vided it is first ascertained that the reagent is of sufficiently
indicated by warming of reactants, but may not form crystals.
high purity to permit its use without lessening the accuracy of
NOTE 6—Add the water quickly to keep the reactants from solidifying
the determination.
and to minimize the loss of HCl.
8.2 Purity of Water—Unless otherwise indicated, references
11.2 Wash the sides of the beaker with water and remove
to water shall be understood to mean reagent water as defined
and wash the stirring bar. Cool the beaker in an ice bath to
by Type I of Specification D 1193.
about 10°C and add 10 drops of HNO . Titrate potentiometri-
8.3 Concentrated Nitric Acid (HNO sp gr 1.42).
cally with 0.01 N AgNO solution using a silver-silver chloride
8.4 Methanol.
electrode pair. If the chlori
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