1、Designation: D1726 11Standard Test Methods forHydrolyzable Chloride Content of Liquid Epoxy Resins1This standard is issued under the fixed designation D1726; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover the determination of the
3、easilyhydrolyzable chloride content of liquid epoxy resins which aredefined as the reaction product of a chlorohydrin and a di- orpolyfunctional phenolic compound.NOTE 1There is no known ISO equivalent to this standard.1.1.1 In Test Method A, the easily hydrolyzable chloride issaponified with potass
4、ium hydroxide and directly titrated withhydrochloric acid. This test method can be used for concen-trations of 1 weight % and below.1.1.2 In Test Method B, the easily hydrolyzable chloride isagain saponified with potassium hydroxide, then titrated po-tentiometrically with silver nitrate. This test m
5、ethod can beused for concentrations of 5 to 2500 ppm hydrolyzablechloride.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its
6、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 hazardstatements see Sections 10 and 16.2. Referenced Documents2.1 ASTM Standards:2D329 Specification
7、for AcetoneD841 Specification for Nitration Grade TolueneD1193 Specification for Reagent WaterD3620 Specification for Glacial Acetic AcidD6440 Terminology Relating to Hydrocarbon ResinsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 T
8、he terminology in these test methods follows thestandard terminology defined in Terminology D6440.3.2 Definitions:3.3 hydrolyzable chloride, nthe low level chlorine-containing components of the liquid epoxy resin, typicallyresidual chlorohydrin ethers, which react with water or alcoholto form hydroc
9、hloric acid (HCl).4. Summary of Test Method4.1 The sample is refluxed in the presence of a knownamount of 0.1 N alcoholic potassium hydroxide to saponify thehydrolyzable chlorides.4.2 Test Method AThe amount of potassium hydroxideconsumed in the hydrolysis is a measure of the hydrolyzablechloride co
10、ntent of the resin.4.3 Test Method BThe amount of potassium chloridedetected by direct titration with standard silver nitrate solutionis a measure of the hydrolyzable chloride content of the resin.5. Significance and Use5.1 The hydrolyzable chloride content of liquid epoxy resinsis an important vari
11、able in determining their reactivity and theproperties of coatings made from them. These test methodsmay be used to determine the hydrolyzable chloride content ofmanufactured epoxy resins and confirm the stated hydrolyzablechloride content of purchased epoxy resins.6. Interferences6.1 Unless stated
12、otherwise, the following interferencesapply to both test methods:6.1.1 Test Method AAlkaline substances easily titratableby HCl, can impact the analysis resulting in lower thanexpected results. Likewise, acidic species, that may behave asthe HCl titrant can impact the analysis resulting in higher th
13、an1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.33 on Polymers and Resins.Current edition approved June 1, 2011. Published June 2011. Originallyapproved in 1960. Last
14、 previous edition approved in 2003 as D1726 03. DOI:10.1520/D1726-11.2For 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
15、website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.expected results. Liquid epoxy resin samples should be neutralwhen analyzed by this test method.6.1.2 Test Method BThiocyanate, cyanide, sulfide, bro-mide, iodide, or other subs
16、tances capable of reacting withsilver ion, as well as substances capable of reducing silver ionin acidic solutions will impact the analysis resulting in higherthan expected results.6.1.3 Test Methods A and B (using a visual indicator) maynot be applicable to samples containing heat sensitive impuri-
17、ties, leading to high color in the reacted solution.7. Purity of Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee onAnalytical Reagents of theAmerican Che
18、mical Society,3where such specifications are available. Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shal
19、l be understood to mean reagent water conformingto Type II of Specification D1193.TEST METHOD A 1 Weight % and Below ofHydrolyzable Chloride8. Apparatus8.1 Reflux Apparatus, consisting of a 250-mL Erlenmeyerflask attached to a reflux condenser.8.2 Hot Plate, with variable heat control.8.3 Magnetic S
20、tirrer, with polytetrafluorethylene (PTFE)-coated stirring bar.8.4 Buret.9. Reagents and Materials9.1 Hydrochloric Acid, Standard (0.1 N)Dilute 9 mL ofconcentrated hydrochloric acid (HCl, sp gr 1.19) to 1 L withwater. Standardize against 0.25 g of sodium carbonate(Na2CO3) accurately weighed and diss
21、olved in 75 to 100 mLofwater.9.2 Methyl Ethyl Ketone (MEK).9.3 Phenolphthalein Indicator SolutionDissolve1gofphenolphthalein in 100 mL of methanol, ethanol, or isopropa-nol.9.4 Potassium Hydroxide, Alcohol Solution (0.1 N)Dissolve 5.6 g of potassium hydroxide (KOH) in 1 L ofmethanol (99 %). No stand
22、ardization of the solution is neces-sary.9.5 Toluene (WarningSee Section 10.), conforming toSpecification D841.9.6 Boiling Chips.10. Hazards10.1 Consult the latest regulations and suppliers MaterialSafety Data Sheets regarding all materials used in this method.10.2 Hydrochloric acid and potassium hy
23、droxide are corro-sive. Toluene and methyl ethyl ketone are flammable and theirvapors can be harmful. Precautions should be taken to avoidinhalation and skin or eye contact with these chemicals. Allsample preparations should be done in a well ventilated area,such as a fume hood.11. Procedure11.1 Wei
24、gh to the nearest 0.001 g, 6 to8gofneutralspecimen into a 250-mL glass-stoppered Erlenmeyer flask. Bymeans of a pipette, transfer 50.0 mL of 0.1 N alcoholic KOHsolution into the flask and add 15 mL of toluene. Stopper theflask and swirl to mix.11.2 Prepare a blank in a separate 250-Erlenmeyer flask,
25、adding 15 mL of toluene and 50 mL of 0.1 N alcoholic KOH.Swirl to mix.11.3 Add a few boiling chips and attach each flask to areflux condensers on the hot plate.11.4 Allow each solution to reflux gently for 15 6 1 min ona hot plate. At the end of the reflux period, remove each flaskfrom the hot plate
26、 and cool to room temperature with thecondenser in place.11.5 Rinse down each condenser with 20 mLof toulene thenremove the condensers from the flasks.11.6 Add 3 drops of phenolphthalein indicator solution toeach flask, and titrate with 0.1 N HCl. The end point is detectedwhen 1 drop of 0.1 N HCl ch
27、anges the solution from pink tocolorless.NOTE 2Add 100 mL of MEK to the specimen if required to ensure ahomogeneous solution during titration of the excess KOH solution.12. Calculation12.1 Calculate the weight percent hydrolyzable chloridecontent of the specimen as follows:H 5B 2 V!N 3 3.545W(1)wher
28、e:H = weight percent hydrolyzable chloride,B = HCl required for titration of the blank, mL,V = HCl required for titration of the hydrolyzed speci-men, mL,N = normality of the HCl,3.545 = grams of chlorine per milliequivalent multiplied bythe percentage factor of 100, andW = specimen weight, g.13. Pr
29、ecision13.1 The following criteria should be used for judging theacceptability of results at the 95 % confidence level:13.1.1 RepeatabilityTwo results obtained by the sameoperator should be considered suspect if they differ by morethan 0.02 % absolute.13.1.2 ReproducibilityTwo results obtained by op
30、eratorsin different laboratories should be considered suspect if theydiffer by more than 0.05 weight %.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see An
31、alar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D1726 112TEST METHOD B 5-2500 PPM Hydrolyzable Chloride14. Apparatus14.1 Reflux Apparatus, consisting of a 250-mL
32、Erlenmeyerflask attached to a reflux condenser.14.2 Hot Plate, with variable heat control.14.3 Magnetic Stirrer, with polytetrafluoroethylene (PTFE)-coated stirring bar.14.4 Glass Buret or Automatic Potentiometric Titrator.14.5 Silver Titrode or equivalent.14.6 Boiling Chips.14.7 Analytical Balance,
33、 capable of weighing to 0.001 g.15. Reagents and Material15.1 Acetone,(WarningSee Section 16.) conforming toSpecification D329.15.2 Bromcresol Green Indicator Solution (0.1 %)Dissolve 0.1 g of bromcresol green in 100 mL of water.15.3 Nitric acid, (HNO3) (1 + 1) diluted with water.15.4 Potassium Hydr
34、oxide, alcohol solution (0.1 N)Dissolve 5.6 g of potassium hydroxide (KOH) in 1 L ofmethanol (99 %). No standardization of the solution is neces-sary.15.5 Silver Nitrate, alcohol solution (0.0025 N)Dissolve0.425 g of silver nitrate (AgNO3), weighed to the nearest 0.001g, in L of methanol (99 %). Sta
35、ndardize against hydrochloricacid or sodium chloride (NaCl) solution either gravimetricallyor potentiometrically, frequently enough to detect changes of0.0005 N.15.6 Toluene,(WarningSee Section 16.) conforming toSpecification D841.15.7 Glacial Acetic Acid,(WarningSee Section 16.)conforming to Specif
36、ication D3620.16. Hazards16.1 Consult the latest regulations and suppliers MaterialSafety Data Sheets regarding all materials used in this method.16.2 Nitric acid, glacial acetic acid, potassium hydroxide,and silver nitrate are corrosive. Acetone and toluene areflammable and their vapors can be harm
37、ful. Precautions shouldbe taken to avoid inhalation and skin or eye contact with thesechemicals. All sample preparations should be done in a wellventilated area, such as a fume hood.17. Procedure17.1 Weigh 2 to3gofspecimen, to the nearest 0.005 g, intoa 250-mL Erlenmeyer flask. Add 20 mL of toluene,
38、 20 mL ofacetone, and 50 mL of 0.1 N alcoholic KOH. Swirl or mix untildissolution is complete.17.2 Prepare a blank in a separate 250mL Erlenmeyerflask, adding 20 mL of toluene, 20 mL of acetone, and 50 mLof 0.1 N alcoholic KOH. Swirl to mix.17.3 Add several boiling chips, connect the flasks to sepa-
39、rate reflux condensers, and gently reflux each for 15 6 1 minon a hot plate.17.4 Remove the hot plate from under the flask and allowthe flask and contents to cool to room temperature. Rinse downthe condenser with approximately 20 mL of acetone thenremove from the flasks.17.5 Quantitatively transfer
40、the contents of each flask toseparate 250-mL titration vessels using acetone as washsolution. Dilute each solution to about 125 mL with acetone.17.6 For manual titrations, insert a stirring bar into eachflask, and place on a magnetic stirrer.17.6.1 Add five drops of bromcresol green indicator.17.6.2
41、 While stirring add 50 mL of glacial acetic acid.Alternatively,1+1nitric acid can be added dropwise just untilthe permanent color changes from blue to yellow instead ofadding the acetic acid. (WarningIf using nitric acid, do notadd any excess. Do not acidify the solution until ready to beginthe titr
42、ation. Make certain that the solution is at room tempera-ture before acidifying. These cautions are necessary to preventthe chloride results from being low due to recombination withthe resin.)17.6.3 Titrate with 0.0025 N silver nitrate to the first blueendpoint, stable for 20 seconds.17.7 For automa
43、ted potentiometric titrations, insert a stir-ring bar and place on a magnetic stirrer or attach to the titrationdevice equipped with a stirrer.17.7.1 While stirring add 50 mL of glacial acetic acid.Alternatively,1+1nitric acid can be added dropwise just untilthe permanent color changes from blue to
44、yellow instead ofadding the acetic acid. (WarningIf using nitric acid, do notadd any excess. Do not acidify the solution until ready to beginthe titration. Make certain that the solution is at room tempera-ture before acidifying. These cautions are necessary to preventthe chloride results from being
45、 low due to recombination withthe resin.)17.7.2 Titrate with 0.0025 N silver nitrate to the inflectionpoint using the combination silver electrode and the automatictitrator or buret.18. Calculation18.1 Calculate the parts per million hydrolyzable chloridecontent of the specimen as follows:H 5 V 2 B!
46、N 3 35.45 3 103#/W (2)where:H = parts per million hydrolyzable chloride,B = AgNO3required for the titration of theblank, mL,V = AgNO3required for the titration of thehydrolyzed specimen, mL,N = Normality of the AgNO3,35.45 3 103= grams of chlorine per milliequivalent mul-tiplied by the ppm conversio
47、n of 1 3 106,andW = specimen weight, g.19. Precision19.1 A liquid epoxy resin of approximately 150 ppm hydro-lyzable chloride was sampled and analyzed at five laboratoriesand seven analysts obtained the following results.19.1.1 RepeatabilityThe difference between two resultsobtained by the same anal
48、yst should not vary by more than8.32 % at the 95 % confidence level.19.1.2 ReproducibilityThe difference between two re-sults, each the mean of two determinations, obtained byD1726 113analysts in different laboratories should not vary by more than15.88 % relative at the 95 % confidence level.20. Key
49、words20.1 hydrolyzable chloride; liquid epoxy resin; saponifiablechlorideASTM 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 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 years andif not revise
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