1、Designation: D2522 03 (Reapproved 2008)2Standard Test Method forChlorine Content of Polybutenes Used for ElectricalInsulation1This standard is issued under the fixed designation D2522; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, 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.1NOTEThe mercury warning was editorially added in April 2009.2NOTEIn 7.7, 20 L was changed to 2 L editorially in Aug
3、ust 2009.1. Scope1.1 This test method describes the determination of the totalchloride content of polybutenes used for electrical insulation.1.2 WarningMercury has been designated by EPA andmany state agencies as a hazardous material that can causecentral nervous system, kidney, and liver damage. Me
4、rcury, orits vapor, may be hazardous to health and corrosive tomaterials. Caution should be taken when handling mercury andmercury-containing products. See the applicable product Ma-terial Safety Data Sheet (MSDS) for details and EPAs website(http:/www.epa.gov/mercury/faq.htm) for additional informa
5、-tion. Users should be aware that selling mercury or mercury-containing products, or both, in your state may be prohibited bystate law.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to est
6、ablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardsinformation, see Section 8.2. Referenced Documents2.1 ASTM Standards:2D878 Test Method for Inorganic Chlorides and Sulfates inInsulating OilsD1193 Specificatio
7、n for Reagent Water3. Summary of Test Method3.1 Organically bound chlorine is converted into sodiumchloride by reaction with sodium biphenyl solution. Thesodium chloride formed is extracted with dilute nitric acid, andthe chlorine content of the aqueous phase is determined bypotentiometric titration
8、.4. Significance and Use4.1 Chlorine is normally present in polybutenes in smallamounts, usually below 50 ppm, as organically bound chlorine.Inorganic chloride is normally not present.NOTE 1The qualitative presence or absence of inorganic chloride maybe tested by Test Method D878.5. Interferences5.1
9、 The presence of substances which form insoluble silvercompounds, such as sulfides, will give high results. Suchsubstances are not normally present in polybutenes.6. Apparatus6.1 Separatory Funnel, 250-mL.6.2 Potentiometeric Titrimeter, automatic recording, ormanual.6.3 Electrodes:6.3.1 Silver and g
10、lass electrode combination is preferred.6.3.2 A silver electrode with a mercurous sulfate referenceelectrode is an acceptable alternative.6.4 Microburet, 5-mL, with 0.01-mL divisions.7. Reagents7.1 Purity of ReagentsUse reagent grade chemicals in alltests. Unless otherwise indicated, it is intended
11、that all reagentsshall conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society, wheresuch specifications are available.3Other grades may be used,1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases a
12、nd is the direct responsibility of Subcom-mittee D27.06 on Chemical Test.Current edition approved May 1, 2008. Published June 2008. Originallyapproved in 1969. Last previous edition approved in 2003 as D2522 03. DOI:10.1520/D2522-03R08E02.2For referenced ASTM standards, visit the ASTM website, www.a
13、stm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions o
14、n 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. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.Copyright ASTM International, 100 Barr
15、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.org) for the latest information1provided it is first ascertained that the reagent is of sufficie
16、ntlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Purity of Water Unless otherwise indicated, referencesto water shall be understood to mean reagent grade water asdefined by Type I conforming to Specifications D1193.7.3 Dilute Nitric Acid (2.1 M)Dilute 134 mL o
17、f concen-trated nitric acid to 1.0 L with water.7.4 Isopropyl Alcohol.7.5 Silver Nitrate, Standard Solution (0.025 N)Weighaccurately 0.4247 g of silver nitrate (AgNO3). Transfer it to a1-L volumetric flask and add water to dissolve. Add 3.0 mL ofconcentrated nitric acid (HNO3, relative density (spec
18、ificgravity) 1.42) and then add water to the 1-L mark of thevolumetric flask. Standardize this solution against a purechloride standard. Check the solution at least monthly to assurea constant reagent.7.6 Sodium Chloride, NIST Standard Reference Material919A.NOTE 2Dry the silver nitrate overnight in
19、 a desiccator before makingup the solution. Both the solid material and the solution must be protectedfrom light by storage in brown glassware in the dark.7.7 Sodium Biphenyl SolutionTransfer 300 mL of drytoluene and 58 g of metallic sodium toa2L,three-neckedflask, equipped with a heating mantle, ni
20、trogen gas inlet,mercury seal stirrer, and reflux condenser. Heat until thetoluene refluxes and the sodium melts completely. Start thestirrer, and stir until the sodium is finely dispersed. Cool to lessthan 10C in a suitable bath (not water). Remove the con-denser, and add 1250 mL of dry ethylene gl
21、ycol dimethyl ether.While stirring and passing nitrogen gas over the mixture, add390 g of biphenyl. The reaction should start immediately, asevidenced by the green color of sodium biphenyl. The tem-perature of the reaction mixture should be kept below 30C.When the reaction is complete (112 to 2 h),
22、pour the reagentinto dry 500-mL brown prescription bottles with screw capsand foil liners. The reagent is stable for several months ifrefrigerated. (If any unreacted sodium remains in the reactionflask, add 100 mL of isopropyl alcohol, and place the flask ina hood until the metal has dissolved.)4NOT
23、E 3Two vials (30 mL) of this reagent are normally required togive excess reagent.8. Hazards8.1 Consult OSHA regulations and suppliers MaterialSafety Data Sheets for all materials used in this test method.9. Procedure9.1 Dissolve 35.5 6 0.1 g of polybutene in 25 mL toluenein a 150-mL beaker by stirri
24、ng with a small glass rod. Transferthe solution to a separatory funnel. Rinse the beaker severaltimes with a total of 25 mL toluene and add the rinses to thefunnel.9.2 Add an excess of sodium biphenyl solution into theseparatory funnel. Excess reagent is evidenced by a blue orgreen color.4(See Note
25、2.) Stopper and mix thoroughly bygentle shaking. Vent occasionally to release slight pressure.9.3 Allow the blue-green mixture to stand 5 min to ensurecomplete reaction. Remove stopper, add 2 mL of isopropylalcohol, and swirl with stopper removed until excess reagent isdestroyed.9.4 Add slowly 50 mL
26、 of dilute nitric acid. Contact organicand aqueous phases by gentle swirling and rocking for about 5min. Loosen the stopper occasionally to release slight pressure.Drain the aqueous phase into a beaker. Extract the organicphase twice more with 50-mL portions of dilute nitric acid.Drain the aqueous p
27、hases into the beaker containing the firstextract.9.5 Sulfur compounds are not normally present in poly-butenes. However, if present in amounts which may affectchlorine results significantly, the following procedure is rec-ommended for removal of the sulfur compounds: Charge theaqueous phase from 9.
28、4 to a separatory funnel and add 15 mLof ethyl ether to the mixture. Shake the contents of the funnelvigorously for 1 min, venting to the air frequently. Allow thecontents of the funnel to stand until the two layers separate,then draw off the aqueous layer into a beaker. Extract theorganic layer wit
29、h two 15-mL portions of water, add theaqueous extracts to the beaker, and discard the organic layer.Add a few millilitres of 30 % hydrogen peroxide solution, heatthe contents of the beaker on a steam hot plate until the etherhas evaporated, then boil for 5 min, and cool to roomtemperature. Proceed i
30、n accordance with 9.6.9.6 Place the beaker on the titration stand, and insert theelectrode system. Start the stirrer and record initial reading.Titrate slowly with 0.025 N AgNO3solution, recording read-ings after the addition of each drop of silver nitrate solution.Continue titrating until the point
31、 of maximum change inmillivolt or pH scale reading is passed. Plot the volume ofsilver nitrate as abscissa and voltage or pH reading as ordi-nates. The end point is selected at the point of inflection of thecurve.NOTE 4If the chloride content is known to be high, larger incrementsmay be added until
32、the titration is within 0.3 mLof the expected end point.9.7 BlankTitrate the same volume of solvent without thesample as a blank.10. Calculation10.1 Calculate the amount of total chlorine as follows:Total chlorine, ppm 5 A 2 B!N/W# 335.460where:A = millilitres of AgNO3solution required for titration
33、 ofthe sample,B = millilitres of AgNO3solution required for titration ofthe blank,4Organic Halogen Reagent (Sodium Biphenyl Solution) from SouthwesternAnalytical Chemicals, 209 Pleasant Valley Road, Austin, TX 78704, or the AldrichChemical Co., 1001 W. St. Paul Ave., Milwaukee, WI 53233 has been fou
34、ndsatisfactory. Preparation of sodium biphenyl solution is described in McCoy, TheInorganic Analysis of Petroleum, Chemical Publishing Co., Inc., 212 Fifth Ave.,New York, NY 10010, p. 127. (This book is no longer in publication.)D2522 03 (2008)22N = normality of the AgNO3solution, andW = grams of sa
35、mple used.11. Precision and Bias11.1 PrecisionThis statement is provided for two approxi-mate ranges of results. Insufficient samples were used in theinter-laboratory studies shown In Annex A1 to provide aprecision statement encompassing the expected range of re-sults.11.1.1 Precision for test resul
36、ts near 14 ppm:11.1.1.1 The repeatability standard deviation has been foundto be 3 ppm. Therefore, the results of two properly conductedtests on the same sample by the same operator should not differby more than 8 ppm.11.1.1.2 The reproducibility standard deviation has beenfound to be 4 ppm. Therefo
37、re, the results of two differentlaboratories on identical samples should not differ from eachother by more than 12 ppm.11.1.2 Precision for test results near 60 ppm:11.1.2.1 The repeatability standard deviation has been foundto 3 ppm. Therefore, the results of two properly conducted testson the same
38、 sample by the same operator should not differ bymore than 9 ppm.11.1.2.2 The reproducibility standard deviation has beenfound to be 9 ppm. Therefore, the results of two differentlaboratories on identical samples should not differ from eachother by more than 25 ppm.NOTE 5The above precision statemen
39、ts were determined on poly-butene samples with a viscosity of about 600 cSt at 100C (210F).12. Keywords12.1 chlorine; electrical; insulating; insulation; polybutenesANNEX(Mandatory Information)A1. PRECISION DATAA1.1 Precision data for this test method are tabulated inTable A1.1.ASTM International ta
40、kes 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 determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own r
41、esponsibility.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 addre
42、ssed to ASTM 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 t
43、he 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 (p
44、hone), 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/).TABLE A1.1 ChlorineAin Polybutene Round Robin No. 3Sample Series No. Test No. Laboratory 1 Laboratory 2 Laboratory 3 Laboratory 4 Laboratory 5 Laboratory 6D112151 131013215 8 2 4 22 3 19 10 11 17 5 14418 13 16 8 18E115986358656256 43 9 7 12 3 65 45 64 59 67 67465 8 67 6 6 67AResults expressed in parts per million (ppm).D2522 03 (2008)23
