ASTM D4661-2018 Standard Test Methods for Polyurethane Raw Materials Determination of Total Chlorine in Isocyanates.pdf

1、Designation: D4661 13D4661 18Standard Test Methods forPolyurethane Raw Materials: Determination of Total Chlorinein Isocyanates1This standard is issued under the fixed designation D4661; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi

2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test methods determine the total chlorine content of aromatic isocyanates used as polyurethane

3、raw materials. Thedifference between the total chlorine content and the hydrolyzable chlorine content (see Test Method D4663) is a measure of theamount of o-dichlorobenzene and other ring-substituted chlorinated products that are present. Both procedures are applicable toa variety of organic compoun

4、ds but the amount of sample used may have to be varied. (See Note 1.)1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its us

5、e. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this standard.NOTE 1This standard is identical to

6、ISO 26603.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barr

7、iers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1193 Specification for Reagent WaterD4663 Test Method for Polyurethane Raw Materials: Determination of Hydrolyzable Chlorine of Isocyanates2.2 ISO Standard:3ISO 26603 PlasticsAromatic isocy

8、anates for use in the production of polyurethanesDetermination of total chlorine3. Terminology3.1 DefinitionsFor definitions of terms used in these test methods see Terminology D883.4. Summary of Test Method4.1 In each test method, the organic matter in the sample is destroyed by combustion with oxy

9、gen, the organically combinedchlorine being converted to ionic chloride. The chloride is determined potentiometrically by titration with silver nitrate (AgNO3)solution.4.1.1 Test Method AThe sample is combusted in a pressurized oxygen bomb. ignition vessel.4.1.2 Test Method BThe sample is combusted

10、at atmospheric pressure in a Schniger oxygen flask.41 These test methods are under the jurisdiction of ASTM Committee D20 on Plastics and are the direct responsibility of Subcommittee D20.22 on Cellular Materials -Plastics and Elastomers.Current edition approved Nov. 1, 2013Aug. 1, 2018. Published N

11、ovember 2013August 2018. Originally approved in 1987. Last previous edition approved in 20092013as D4661 - 09.D4661 - 13. DOI: 10.1520/D4661-13.10.1520/D4661-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. ForAnnual Book ofA

12、STM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 For information on the Schniger flask, refer to Microchemie, Springer P

13、ublishers, Vienna, Austria, Vol 42, 1955, p. 123, or Vol 43, 1956, p. 869.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately d

14、epict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM Internat

15、ional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Significance and Use5.1 These test methods can be used for research or for quality control to determine the total chlorine content of aromaticisocyanates. In some instances total chlorine content may correl

16、ate with performance in polyurethane systems.6. Interferences6.1 Bromine and iodine, if present, will react with the silver nitrate (AgNO3) solution leading to an erroneously high totalchlorine value.7. Reagents and Materials7.1 Purity of ReagentsUse reagent-grade chemicals in all tests. Unless othe

17、rwise indicated, it is intended that all reagentsconform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available.5 Other grades may be used, are acceptable, provided it is first ascertained that the reagent is ofsufficient

18、ly high purity to permit its use without lessening the accuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water as defined byType I of Specification D1193.8. Sampling8.1 Since organic isocyanates react with atmospheric

19、 moisture, take special precautions in sampling. Usual sampling methods,even when conducted rapidly, can cause contamination of the sample with insoluble urea. Therefore, blanket the sample with dryair or nitrogen at all times. (WarningMany diisocyanates are known or suspected sensitizers. Over-expo

20、sure to diisocyanatescan lead to adverse health effects, which include the development of occupational asthma and other respiratory, skin and eyeeffects. Engineering controls and/orDiisocyanates are eye, skin and respiratory irritants at concentrations above the occupationalexposure limit (TLV or PE

21、L). Diisocyanates can cause skin and respiratory sensitization (asthma) in some people. Once sensitized,it is essential to limit further exposure to diisocyanates. Use a combination of engineering controls and personal protectiveequipment, including respiratory, skin and eye protection, are to be us

22、ed when there is a potential for to prevent over-exposure todiisocyanates. The Consult the product suppliers Safety Data Sheet (SDS) providesfor more detailed information about potentialadverse health effects and other importantspecific safety and handling information. Always follow the specific ins

23、tructionsprovided on the SDS.instructions for the product.)9. Test Conditions9.1 Since isocyanates react with moisture, it is highly recommended It is essential that moisture be excluded from the sampleby all means possible to ensure the accuracy of measurements in this standard. See Section 8 of th

24、is standard for guidance on howto keep moisture out of the sample.TEST METHOD ATOTAL CHLORINE BY OXYGEN BOMB IGNITION VESSEL10. Apparatus10.1 Weighing Bottle and Balance, suitable for weighing a liquid sample by difference to the nearest 0.5 milligram.10.2 Oxygen Bomb Ignition Vessel Apparatus.610.3

25、 Fuse Wire, iron-nickel-chromium, No. 34 B chlorine; isocyanates; oxygen bomb; ignition vessel; polyurethane raw materials; Schniger ignition;titrationSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D4661 - 09D4661 - 13) that may

26、impact the use of this standard. (November(August 1, 2013)2018)(1) Added that ISO 26603 is equivalent to these methods.(2) Added ISO 26603 as a reference.(3) ReplacedUpdated wording used in the Sampling section with wordingto be consistent with the other polyurethane raw materialmethods.(2) Removed

27、recommendation for lab humidity.(3) Removed nonstandard concentration usage “1+1” throughout methods.(4) Removed duplicate calculation equations.Corrected typo in units from Newtons to normality in section 16.3.(5) Renumbered footnotes.Changed bomb to ignition vessel throughout.ASTM International ta

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