1、Designation: D 4661 03Standard 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 (e) 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 ma
3、terials.The difference between the total chlorine content and thehydrolyzable chlorine content (see Test Method D 4663) is ameasure 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 b
4、ut 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 brackets are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is t
5、heresponsibility 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 119
6、3 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 organi
7、c 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 corr
9、elate 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 othe
10、rwise 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.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type I of Specification D 1193.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics a
12、nd are the direct responsibility of Subcommittee D20.22 on CellularPlastics.Current edition approved November 1, 2003. Published January 2004. Originallyapproved in 1987. Last previous edition approved in 1998 as D 4661 - 98.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcon
13、tact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document 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
14、, p. 869.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on 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 P
15、harmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.1*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.8. Sampling8.1 Since organ
16、ic 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.)Usual sampling metho
17、ds (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 laboratoryhumidity low, p
18、referably 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 chlorine; isocyanates; ox
19、ygenbomb; polyurethane raw materials; Schniger ignition; titration9Arthur H. Thomas Co., Catalog No. 6513C05.D 4661 034SUMMARY OF CHANGESThis section identifies the location of selected changes to these test methods. For the convenience of the user,Committee D20 has highlighted those changes that ma
20、y impact the use of these test methods. This section mayalso include descriptions of the changes or reasons for the changes, or both.D 4661 - 03:(1) Paragraph 1.1 - Modified the Scope to reflect industryexperience. Expanded to include other aromatic isocyanates.(2) Paragraph 4.1.2 - Added umlaut ()
21、over o.(3) Section 5 - Modified Significance and Use to reflect scopechange.(4) Paragraph 10.2 - Corrected footnote to remove incorrectaddress.(5) Paragraph 10.3 - Corrected footnote to remove incorrectaddress.(6) Paragraph 10.5 - Removed footnote because item would beobtained from the actual titrat
22、or manufacturer.(7) Paragraph 10.6 - Removed footnote because item would beobtained from the actual titrator manufacturer.(8) Paragraph 11.3 - Renumbered footnote to reflect previouschanges.(9) Paragraph 12.1 - Removed polishing materials footnoteinformation because such polishing is not performed i
23、n prac-tice.(10) Paragraph 15.1 - Corrected footnotes to reflect currentchanges.(11) Section 17 - Removed parenthetical reference to Note 9.(12) Paragraph 17.2 - Removed sentence about practice andjudging by eye as unnecessary since a specific weight isidentified.(13) Paragraph 17.3 - Adjusted footn
24、otes to reflect currentpractice and changes. Changed ignitor to reflect current tech-nology.(14) Section 19 - Added “full” to emphasize that someprecision data is available.(15) Section 20 - Added “bomb” after “oxygen” and “ignition”to “Schniger” to better describe the key words.(16) Incorporated pr
25、ecautionary notes into the main body of thetest method in order to conform with ASTM form and style.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that dete
26、rmination 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 by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or
27、 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 receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel tha
28、t 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 International, 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 035
