1、Designation: D 4661 09Standard Test Methods forPolyurethane Raw Materials: Determination of Total Chlorinein Isocyanates1This standard is issued under the fixed designation D 4661; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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 contentof aromatic isocyanates used as polyurethane raw mat
3、erials.The difference between the total chlorine content and thehydrolyzable chlorine content (see Test Method D 4663)isameasure of the amount of o-dichlorobenzene and other ring-substituted chlorinated products that are present. Both proce-dures are applicable to a variety of organic compounds but
4、theamount of sample used may have to be varied. (See Note 1.)1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is th
5、eresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsD 1193
6、 Specification for Reagent WaterD 4663 Test Method for Polyurethane Raw Materials: De-termination of Hydrolyzable Chlorine of Isocyanates3. Terminology3.1 DefinitionsFor definitions of terms used in these testmethods see Terminology D 883.4. Summary of Test Method4.1 In each test method, the organic
7、 matter in the sample isdestroyed by combustion with oxygen, the organically com-bined chlorine being converted to ionic chloride. The chlorideis determined potentiometrically by titration with silver nitrate(AgNO3) solution.4.1.1 Test Method AThe sample is combusted in a pres-surized oxygen bomb.4.
8、1.2 Test Method BThe sample is combusted at atmo-spheric pressure in a Schniger oxygen flask.35. Significance and Use5.1 These test methods can be used for research or forquality control to determine the total chlorine content ofaromatic isocyanates. In some instances total chlorine contentmay corre
9、late with performance in polyurethane systems.6. Interferences6.1 Bromine and iodine, if present, will react with the silvernitrate (AgNO3) solution leading to an erroneously high totalchlorine value.7. Reagents and Materials7.1 Purity of ReagentsUse reagent-grade chemicals in alltests. Unless other
10、wise indicated, it is intended that all reagentsconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society where suchspecifications are available.4Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to
11、permit its use without lessening the accuracy ofthe determination.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.22 on CellularMaterials - Plastics and Elastomers.Current edition approved Feb. 1, 2009. Published M
12、arch 2009. Originallyapproved in 1987. Last previous edition approved in 2003 as D 4661 - 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document
13、Summary page onthe ASTM website.3For information on the Schniger flask, refer to Microchemie, SpringerPublishers, Vienna, Austria, Vol 42, 1955, p. 123, or Vol 43, 1956, p. 869.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on
14、the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.1*A Summary of Changes section appears
15、at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type I of Specification D 1193.8. Sam
16、pling8.1 Since organic isocyanates react with atmospheric mois-ture, take special precautions in sampling. (WarningOrganicisocyanates are toxic when they are absorbed through the skin,or when the vapors are breathed. PrecautionProvide ad-equate ventilation and wear protective gloves and eyeglasses.)
17、Usual sampling methods (for example, sampling an open drumwith a thief), even when carried out rapidly, can causecontamination of the sample with insoluble urea. Therefore,blanket the sample with dry air or nitrogen at all times.9. Test Conditions9.1 Since isocyanates react with moisture, keep labor
18、atoryhumidity low, preferably around 50 % relative humidity.TEST METHOD ATOTAL CHLORINE BY OXYGENBOMB10. Apparatus10.1 Weighing Bottle and Balance, suitable for weighing aliquid sample by difference to the nearest 0.5 mg.10.2 Oxygen Bomb Apparatus.510.3 Fuse Wire, iron-nickel-chromium, No. 34B chlor
19、ine; isocyanates; oxygenbomb; polyurethane raw materials; Schniger ignition; titration8Arthur H. Thomas Co., Catalog No. 6513C05.D 4661 094SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D 4661 - 03) that may impact the use of thi
20、s standard. (February 1, 2009)(1) Removed reference to specific titrator. Referenced modelhas been replaced and there are many others commerciallyavailable.(2) Renumbered Footnotes 7-9 to reflect removal of Footnote6.ASTM International takes no position respecting the validity of any patent rights a
21、sserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time
22、 by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will re
23、ceive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM In
24、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 4661 095
