1、Designation: D 2522 03Standard Test Method forChlorine Content of Polybutenes Used for ElectricalInsulation1This standard is issued under the fixed designation D 2522; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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. Scope1.1 This test method describes the determination of the totalchloride content of polybutenes used for electrical insulation.
3、1.2 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific h
4、azardsinformation, see Section 8.2. Referenced Documents2.1 ASTM Standards:D 878 Test Method for Inorganic Chlorides and Sulfates inInsulating Oils2D 1193 Specification for Reagent Water3D 2296 Specification for Continuity of Quality of ElectricalInsulating Polybutene Oil for Capacitors23. Summary o
5、f 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.4. Significance and Use4.1 Chl
6、orine 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 D 878.5. Interferences5.1 The presence of substances wh
7、ich 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 glass electrode combination is
8、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 that all reagentsshall conform
9、 to the specifications of the Committee onAnalytical Reagents of the American Chemical Society, wheresuch specifications are available.4Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe dete
10、rmination.7.2 Purity of Water Unless otherwise indicated, refer-ences to water shall be understood to mean reagent grade wateras defined by Type I conforming to Specifications D 1193.7.3 Dilute Nitric Acid (2.1 M)Dilute 134 mL of concen-trated nitric acid to 1.0 L with water.7.4 Isopropyl Alcohol.7.
11、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 (specificgravity) 1.42) and then add water to the 1-L mark of thevolumetric f
12、lask. 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 a desiccator before making1This test method is under the jurisdiction o
13、f ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-mittee D27.06on Chemical Test.Current edition approved April 10, 2003. Published June 2003. Originallyapproved in 1969. Last previous edition approved in 1995 as D 2522 95.2Annual Book of ASTM S
14、tandards, Vol 10.03.3Annual Book of ASTM Standards, Vol 11.01.4Reagent 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, B
15、DH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.up the solution. Both the solid material
16、 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 to a 20 L, three-neckedflask, equipped with a heating mantle, nitrogen gas inlet,mercury seal stirrer, and reflux condenser. H
17、eat 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 glycol dimethyl ether.While stirring and passing nitrogen gas ov
18、er 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), pour the reagentinto dry 500-mL brown prescription bottles wit
19、h 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.)5NOTE 3Two vials (30 mL) of this reagent are normally required tog
20、ive 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 stirring with a small glass rod. Transferthe solution to a separator
21、y 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.5(See Note 2.) Stopper and mix thoroughly bygentle shaking. Vent occasion
22、ally 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 of dilute nitric acid. Contact organicand aqueous phases by g
23、entle 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 phases into the beaker containing the firstextract.9.5 Sulfur c
24、ompounds 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 9.4 to a separatory funnel and add 15 mLof ethyl ether to the mi
25、xture. 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 with two 15-mL portions of water, add theaqueous extracts to the
26、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 in accordance with 9.6.9.6 Place the beaker on the titration st
27、and, 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 of maximum change inmillivolt or pH scale reading is passed.
28、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 the titration is within 0.3 mL of the expected end point.9.7 B
29、lankTitrate 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# 3 35.460where:A = millilitres of AgNO3solution required for titration ofthe sample,B = millilitres of AgNO3solution required for
30、 titration ofthe blank,N = normality of the AgNO3solution, andW = grams of sample 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 statemen
31、t encompassing the expected range of re-sults.11.1.1 Precision for test results 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.
32、1.2 The reproducibility standard deviation has beenfound to be 4 ppm. Therefore, 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 fou
33、ndto 3 ppm. Therefore, the results of two properly conducted testson the same sample by the same operator should not differ bymore than 9 ppm.5Organic Halogen Reagent (Sodium Biphenyl Solution) from SouthwesternAnalytical Chemicals, 209 Pleasant Valley Road, Austin, TX 78704, or the AldrichChemical
34、Co., 1001 W. St. Paul Ave., Milwaukee, WI 53233 has been foundsatisfactory. 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.)D 2522 0321
35、1.1.2.2 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 statements were determined on poly-butene samples with a viscosity of abou
36、t 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 takes no position respecting the validity of any patent rights asser
37、ted 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 by
38、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 receiv
39、e 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 Intern
40、ational, 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
41、 the ASTM website(www.astm.org).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 4 22 3 19 10 11 17 5 14418 13 16 8 8E1159863 586561256 43 9 72 3 65 45 64 59 67 67465 8 67 6 6 67AResults expressed in parts per million (ppm).D 2522 033
