1、Designation: D3566 03 (Reapproved 2014)Standard Practice forRubberDetermination of Bromine in the Presence ofChlorine by Oxygen Combustion1This standard is issued under the fixed designation D3566; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, 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.1. Scope1.1 This practice covers the determination of bromine andchlorine in rubber.1.2 This procedure
3、is applicable to raw or cured NR, SBR,BR, IR, IIR, CIIR, BIIR, and EPDM rubbers and blends ofthese.1.3 Iodine interferes, but substances such as Zn2+,S,CN,and (CO3)2do not.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5
4、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. Specific safetypre
5、cautions are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2E200 Practice for Preparation, Standardization, and Storageof Standard and Reagent Solutions for Chemical AnalysisE443 Test Method for Sulfur in Organic Compounds byOxygen Flask Combustion (Withdrawn 1996)33. Summary of Pract
6、ice3.1 Samples of rubber, wrapped in filter paper, are burned inan oxygen combustion flask containing an aqueous solution ofhydrogen peroxide and sodium bisulfite. The carbon andhydrogen of the organic matter are oxidized. The combustedsolution is titrated directly for bromine and chlorine.4. Signif
7、icance and Use4.1 This practice outlines a method for the determination ofbromine and chlorine, alone or together.4.2 CIIR and BIIR rubbers contain small amounts of chlo-rine and bromine and CR rubbers contain large amounts ofchlorine. For quality control and research and development, itis sometimes
8、 necessary to determine the amount of thesehalogens in rubber. This practice can be used for thesepurposes.5. Apparatus5.1 Oxygen Combustion Flask (Schniger Flask)Achemical-resistant,4thick-walled oxygen combustion flask,51000 cm3, withSJ 35/25 ball-joint stopper, platinum samplecarrier, and pinch c
9、lamp.5.2 Infrared Safety Igniter,5,6with cabinet and infrared light(an electrical igniter is also satisfactory).5.3 Magnetic Stirring Bar, covered with a chemical-resistant coating,5,7approximately 25 mm (1 in.) long, withouta spinning ring around the center.5.4 Magnetic Stirrer.5.5 Filter Paper, 30
10、 by 30 mm, with a 35-mm extension,black5,8for infrared or white5,9for electrical ignition.5.6 pH Meter,10equipped with a billet-type silver electrode11and a calomel electrode, in which the potassium chloride1This practice is under the jurisdiction ofASTM Committee D11 on Rubber andis the direct resp
11、onsibility of Subcommittee D11.11 on Chemical Analysis.Current edition approved July 1, 2014. Published November 2014. Originallyapproved in 1977. Last previous edition approved in 2009 as D3566 03 (2009).DOI: 10.1520/D3566-03R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org,
12、orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Borosilicate glass has been found satisfactory
13、.5The sole source of supply of the apparatus known to the committee at this timeis A. H. Thomas Co., Philadelphia, PA, Catalog No. 6514-F20. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration a
14、t a meeting of theresponsible technical committee,1which you may attend.6The sole source of supply of the apparatus known to the committee at this timeis A. H. Thomas Co., Philadelphia, PA, Catalog No. 6516-G10.7Polytetrafluoroethylene has been found satisfactory.8The sole source of supply of the ap
15、paratus known to the committee at this timeis A. H. Thomas Co., Philadelphia, PA, Catalog No. 6514-F65.9The sole source of supply of the apparatus known to the committee at this timeis A. H. Thomas Co., Philadelphia, PA, Catalog No. 6513-C75.10A. Beckman pH meter Model SS-2 has been found satisfacto
16、ry.11Coleman Catalog No. 3-571 has been found satisfactory.Any equivalent silverelectrode may be used. The electrode should not be coated by the user, especially forTest Method B. It may, however, be polished with a mild abrasive such as powderedkitchen cleanser, so that it is bright and shiny.Copyr
17、ight ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1solution has been replaced by a saturated potassium nitratesolution, or equivalent automatic titrator.6. Reagents6.1 Silver Nitrate Solution (0.001 M) must be freshlyprepared. Pipet 10.0 cm3o
18、f standard120.1 M silver nitratesolution into a 1-dm3volumetric flask. Dilute to volume.Protect from light. Determine its molarity by titrating anaccurately weighed sample of the reagent grade KCl or NaCl.Calculate the molarity as follows:Molarity 5 A 31000#/B 3 C! (1)where:A = grams of chloride wei
19、ghed,B = molecular mass of chloride used, andC = titration volume, cm3.6.2 Sodium Bisulfite, 35 % in water,6.3 Hydrogen Peroxide, 3 % solution,6.4 Nitric Acid (6M).6.5 Aluminum Nitrate,6.6 Isopropyl Alcohol,6.7 Methyl Orange Indicator (1 % solution in methylalcohol), and6.8 Oxygen in Compressed Gas
20、Cylinder.7. Safety Precautions7.1 The following safety precautions must be observed inthe combustion of rubber samples:7.1.1 The flask shall not contain residues of organic solventsor vapor, which could cause an explosion. Any such solventsused for cleaning the flask should be rinsed out repeatedly
21、withwater.7.1.2 The pressure generated by the rapid combustion couldcause the flask to explode. Therefore, combustion shall takeplace in a safety chamber with the door locked or behind asafety shield or hood shield (preferably in a safety chamber thatis behind a shield); the hands and face shall be
22、withdrawnbehind a screen before the flame reaches the sample itself.Goggles or a face shield should be worn while observing thecombustion procedure.7.1.3 The flask should be left in the safety chamber until thelast spark is extinguished.At this point it is removed; but sincea slight vacuum is formed
23、, goggles or a face shield should stillbe worn.8. Sampling8.1 The representative test portion selected for analysismust be milled or cut into very fine pieces before weighing.8.2 Due to the small sample size, the rubber and filter papershould be protected from contamination, and all operationsprior
24、to combustion should be carried out while wearing plasticgloves.9. Procedure9.1 Place 10 cm3of water, five drops hydrogen peroxide,and2cm3of sodium bisulfite solution into the combustionflask.9.2 Fold the filter paper into a U-shaped sample boat.9.3 Weigh a sample of 80 to 100 mg (which should notex
25、ceed approximately 0.25 milliequivalents of bromine) to thenearest 0.1 mg. Place the sample into the folded filter paperboat.9.4 Place the folded paper firmly in the platinum samplecarrier hung on the hook of the stopper, with the pointed end ofthe paper projecting outward.9.5 Insert a tube from the
26、 oxygen cylinder close to thebottom of the flask and admit oxygen rapidly for 5 min.9.6 Carefully remove the oxygen tube and stopper the flask.9.7 With the stopper upright, clamp the stopper tightly withthe pinch clamp.9.8 Place the flask in the infrared igniter chamber with thepointed end of the pa
27、per in line with the infrared beam andapproximately perpendicular to it. Close the door and turn onthe infrared light (or electric igniter) until the paper ignites.9.9 After combustion is complete, moisten the stopperexternally with a few drops of water to avoid loss of halogen.Let sit 1 min. Shake
28、the flask. Allow to rest for 30 min.9.10 Remove the pinch clamp, tilt the stopper to release thevacuum, and open the flask.9.11 Where the bromine and chlorine content, or both, islow, repeat the procedure of 9.1 to 9.10, burning anothersample of about the same size over the same liquid.9.12 Open the
29、 flask; wash sides, stopper, and carrier withwater.9.13 Add 3.5 cm3of HNO3solution. Close flask and shaketo dissolve ash in basket.9.14 Pour solution into 400 cm3beaker containing a mag-netic stirrer.9.15 Wash the flask with isopropyl alcohol, adding wash-ings to beaker. The final composition should
30、 be close to 80 %alcohol, 20 % water.9.16 Add 4 g aluminum nitrate and two drops methylorange. Solution should turn red. If not, add HNO3until redcolor appears.9.17 Titrate the solution with 0.001 M AgNO3(6.1), usingthe pH meter arrangement described (5.6) or an equivalentautomatic titrator. Add tit
31、rant in increments of 0.01 cm3.9.18 The first inflection point on the curve of millivoltsversus cubic centimetres of titrant, represents bromide; thesecond inflection point represents chloride. The end point is thepoint of maximum change in emf for an increment of titrant.9.19 For a better end point
32、, a known amount of bromide andchloride may be added to the sample solution before titration.Deduct this amount from the total titration.12The 0.1 M silver nitrate solution should be prepared in accordance withPractice E200 or may be purchased.D3566 03 (2014)29.20 Carry a blank throughout the entire
33、 procedure, usingthe same quantity of reagents, but omitting the sample.10. Calculation10.1 Calculate the bromine content as follows:Bromine, % 5 B 2 A! 3 M 37.99/W (2)where:B = volume of AgNO3solution required for titration to thefirst inflection point, cm3,A = volume of AgNO3solution required for
34、titration of theblank,M = molarity of the AgNO3solution, andW = mass of rubber samples burned in the flask, g.10.2 Calculate the chlorine content as follows:Chlorine, % 5 C 2 B! 3 M 33.55/W (3)where:C = volume of AgNO3solution required for titration to thesecond inflection point, cm3,B = volume of A
35、gNO3solution required for titration to thefirst inflection point, cm3,M = molarity of the AgNO3solution, andW = mass of rubber samples burned in the flask, g.11. Report11.1 Report the following information:11.1.1 Sample identification, and11.1.2 Test result, which is the average of two determina-tio
36、ns.12. Precision and Bias12.1 This practice has not been tested in a round-robin testprogram.13. Keywords13.1 bromine; chlorine; oxygen combustionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
37、 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 the responsible technical committee and must be reviewed every five
38、 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 receive careful consideration at a meeting of theresponsible technical co
39、mmittee, 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
40、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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 03 (2014)3
