1、Designation: D4877 10Standard Test Method forPolyurethane Raw Materials: Determination of APHA Colorin Isocyanates1This standard is issued under the fixed designation D4877; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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 This test method measures the color of clear liquids. Itis applicable only to materials whose color-producing bodi
3、eshave light-absorption characteristics similar to those of theplatinum cobalt color standards used.2(See Test MethodD1209 and Note 1.)1.2 The values stated in SI units are to be regarded asstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its
4、use. It is theresponsibility 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 1This standard is equivalent to ISO 6271-1:2004.2. Referenced Documents2.1 ASTM Standards:3D883 Terminology Rel
5、ating to PlasticsD1193 Specification for Reagent WaterD1209 Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)D5386 Test Method for Color of Liquids Using TristimulusColorimetry2.2 ISO Standards:ISO 6271-1:2004 Clear LiquidsEstimation of Color bythe Platinum Cobalt Scale43. Terminology3.
6、1 For definitions of terms used in this test method seeTerminology D883.4. Summary of Test Method4.1 The color of the material to be tested is compared to aseries of platinum cobalt color standards, designated by mg ofPt/mLof standard solution. The results are reported as the colorstandard, which be
7、st matches the sample (Note 2).NOTE 2Color of liquids also can be measured by visible spectroscopyand the results converted to any of several color scales. These results canbe converted to the APHA scale by appropriate manipulations, as forexample in Test Method D5386.5. Significance and Use5.1 This
8、 test method can be used for research or for qualitycontrol to characterize isocyanates used in polyurethane prod-ucts.5.2 For toluene diisocyanate, results from this test methodcan relate to reactivity or performance in polyurethane sys-tems.6. Apparatus6.1 Nessler Tubes, matched, 100-mL tall-form.
9、7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.5
10、Other grades can be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to 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
11、IV or better of Specification D1193.7.3 Cobaltous Chloride Hexahydrate (CoCl26H2O).7.4 Concentrated Hydrochloric Acid (sp. gr. 1.19).7.5 Potassium Chloroplatinate (K2PtCl6).1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D
12、20.22 on Cellular Materials -Plastics and Elastomers.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapproved in 1988. Last previous edition approved in 2004 as D4877 - 04. DOI:10.1520/D4877-10.2See Standard Methods for the Examination of Water, Sewage, and IndustrialWastes
13、, AM. Public Health Assn., 1015 15th St. NW Washington, DC 20005.3For 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 Summary page onthe ASTM webs
14、ite.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the Ameri
15、can Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Inte
16、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Sampling8.1 Since organic isocyanates react with atmospheric mois-ture, take special precautions in sampling. Usual samplingmethods, even when conducted rapidly, can cause contamina-tion of the sample w
17、ith insoluble urea. Therefore, blanket thesample with dry air or nitrogen at all times. (WarningManydiisocyanates are known or suspected sensitizers. Over-exposure to diisocyanates can lead to adverse health effects,which may include the development of occupational asthmaand other respiratory, skin,
18、 and eye effects. Engineering con-trols, or personal protective equipment or both, includingrespiratory, skin, and eye protection, are to be used when thereis a potential for over-exposure to diisocyanates. The productsuppliers Material Data Safety Sheet (MSDS) provides moredetailed information abou
19、t potential adverse health effects andother important safety and handling information. Alwaysfollow the specific instructions provided on the MSDS.)9. Preparation of Color Standards (See Note 3)9.1 Add 500 mL distilled water to a 1000-mL volumetricflask. Add 100 mL HCl and mix well. Weigh to the nea
20、rest 1mg of 1.245 g of K2PtCl6and transfer it to the volumetric flask(Note 4). Add 1.0 g of crystallized CoCl26H2O. Dilute thesolution in the flask to the mark with distilled water and mixthoroughly. The color of this standard solution is equivalent to500 color units (500 mg metallic platinum/L).NOT
21、E 3Alternatively, use a Hellige Aquatester Model 611-A orequivalent instrument having permanent sealed color standards (HelligeModel 611-10 color comparator disc of APHA cobalt-platinum colorstandards).NOTE 4If potassium chloroplatinate is not available, dissolve 0.500 gof pure metallic platinum in
22、aqua regia with heating; then remove theHNO3by repeated evaporations with fresh portions of HCl. Dissolve thisproduct together with 1 g of crystallized CoCl26H2O as directed in 9.1.9.2 Prepare the required color standards by diluting the No.500 standard solution as shown in Table 1. If a more exactc
23、olor comparison is desired, prepare additional standards tosupplement those given (one color unit is equivalent to 1 mgmetallic platinum/L). When not in use, standards are to besealed to avoid evaporation and contamination.10. Procedure10.1 Fill one of two matched 100-mL tall-form Nesslertubes to th
24、e mark with the sample. Fill the second tube to themark with the standard that seems to best match the color of thesample.10.2 Compare the colors of the sample and the standard byviewing vertically down through the tubes against a whitebackground. Replace the liquid in the second tube with lighteror
25、 darker standards until an exact match is obtained. (See Note5.)NOTE 5Rinse the second tube at least once with the replacementstandard before filling the tube to the mark with it.11. Report11.1 Report the color number of the standard that is closestin color to the sample. If the sample appears exact
26、ly halfwaybetween two standards, report the color number of the darkerstandard.12. Precision and Bias12.1 PrecisionAttempts to develop a precision and biasstatement for this test method have not been successful. Forthis reason, data on precision and bias cannot be given;however, the precision is exp
27、ected to be equivalent to thatreported in ISO 6271-1:2004. Because this test method doesnot contain a numerical precision and bias statement, it shallnot be used as a referee test method in case of dispute. Contactthe Chairman, Subcommittee D20.22 (Section D20.22.01),ASTM, 100 Barr Harbor Drive, PO
28、Box C700, West Consho-hocken, PA19428-2959, if you are interested in participating inthe development of precision and bias data for this standard.12.1.1 RepeatabilityBased on ISO 6271-1:2004, it wouldbe expected that two replicate test results, each the mean ofduplicates, run on the same day, using
29、the same equipment, bythe same analyst, are to be considered to be different only ifthey differ by more than 5 % relative.12.1.2 ReproducibilityBased on ISO 6271-1:2004,itwould be expected that two test results, run on different days,each the mean of duplicates, using different equipment, by thediff
30、erent analysts, are to be considered to be different only ifthey differ by more than 15 % relative.12.2 BiasThe bias of this test method has not yet beendetermined.13. Keywords13.1 APHA; color; isocyanates; platinum-cobalt scale poly-urethane raw materials; Pt/Co scaleTABLE 1 Color StandardsColor St
31、andard NumberNumber 500 Standard,mLWater, mL1 0.2 99.83 0.6 99.45 1.0 99.010 2.0 98.015 3.0 97.018 3.6 96.420 4.0 96.025 5.0 95.030 6.0 94.040 8.0 92.050 10.0 90.080 12.0 88.070 14.0 86.080 16.0 84.090 18.0 82.0100 20.0 80.0120 24.0 76.0140 28.0 72.0160 32.0 68.0180 36.0 64.0200 40.0 60.0300 60.0 40
32、.0400 80.0 20.0500 100.00 0.0D4877 102SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D4877 - 04)that may impact the use of this standard. (January 1, 2010)(1) Revised 1.3, 8.1, 12.1.1, and 12.1.2.ASTM International takes no posi
33、tion respecting the validity of any patent rights asserted 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 responsibili
34、ty.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 withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to AST
35、M International Headquarters. Your comments will receive 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
36、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D4877 103
