D1726

Designation: D 1726 – 03

Standard Test Methods for

Hydrolyzable Chloride Content of Liquid Epoxy Resins 1 This standard is issued under the fixed designation D 1726; the number immediately following the designation indicates the year of  original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript supers cript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Sco Scope pe

2.2 Other Documents: OSHA OSH A Reg Regula ulatio tions, ns, 29 CFR CFR,, par paragr agraph aphss 191 1910.1 0.1000 000 and 1910.12003

1.1 These test methods methods cover the determination determination of the easily easily hydrolyzable chloride content of liquid epoxy resins which are defined as the reaction product of a chlorohydrin and a di- or polyfunctional phenolic compound. 1.1.1 In Test Test Meth Method od A, the easily hydrolyzabl hydrolyzablee chlor chloride ide is saponified with potassium hydroxide and directly titrated with hydrochloric acid. This test method can be used for concentrations trat ions of 1 weight % and below. below. 1.1.2 In Test Test Method B, the easily hydrolyzab hydrolyzable le chloride chloride is again saponified with potassium hydroxide, then titrated potentiomet tenti ometrica rically lly with silver nitr nitrate. ate. This test method can be used us ed fo forr co conc ncen entr trat atio ions ns of 5 to 25 2500 00 pp ppm m hy hydr drol olyz yzab able le chloride. 1.2 The values values stated stated in SI units are to be reg regard arded ed as the standard. The values given in parentheses are for information only. standa ndard rd does not purport purport to add addre ress ss all of the 1.3   This sta safe sa fety ty co conc ncer erns ns,, if an anyy, as asso soci ciat ated ed wi with th it itss us use. e. It is th thee responsibility of the user of this standard to establish appro priate safety and health practices and determine the applicability of regulatory limitations prior to use.  For specific hazard statements see Sections 9 and 15.

3. Terminology 3.1 For defini definition tionss rela relating ting to hydro hydrocarbo carbon n resi resins ns see TerTerminology D 6440. 4. Summ Summary ary of Test Test Method 4.1 Th 4.1 Thee sa samp mple le is re reflu fluxe xed d in th thee pr pres esen ence ce of a kn know own n amount of 0.1  N  alcoholic  alcoholic potassium hydroxide. The amount of  potassium hydroxide consumed in the hydrolysis is a measure of the hydrolyzable chloride content of the resin. 5. Signi Significanc ficancee and Use 5.1 The hydrolyzable chloride chloride content of liquid epoxy epoxy resins is an important variable in determining their reactivity and the properties of coatings made from them. These test methods may be used to determine the hydrolyzable chloride content of  manufactured epoxy resins and confirm the stated hydrolyzable chloride content of purchased epoxy resins. 6. Appa Apparatus ratus 6.1   Reflux Apparatus, consisting of a 250-mL Erlenmeyer flask fla sk at atta tach ched ed to a re reflu flux x co cond nden ense serr an and d a ho hott pl plat atee wi with th variable heat control.

2. Referenced Documents 2.1   ASTM Standards: 2 D 329 Speci Specificat fication ion for Acetone D 841 Specification for Nitration Grade Toluene Toluene D 1193 1193 Specification for Reagent Water D 3620 Speci Specificat fication ion for Glaci Glacial al Acetic Acid Acid D 6440 Ter Terminology minology Relating to Hydrocarbon Resins E 691 Pract Practice ice for Condu Conductin cting g an Inte Interlabo rlaborator ratory y Study to Determine the Precision of a Test Method

7. Purit Purity y of Reagents 7.1   Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents Reagents of the American Chemical Chemical Society, Society, 4 where such specifications are available. Other grades may be used, use d, pro provid vided ed it is firs firstt asc ascert ertain ained ed tha thatt the reagent reagent is of 

1 This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of  Subcommittee Subco mmittee D01.33 on Polym Polymers ers and Resins. Currentt edition approved Curren approved Dec. 1, 2003 2003.. Publi Published shed January 2004. Originally approved in 1960. Last previous edition approved in 1990 as D 1726 – 90 (1996). 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@ [email protected] astm.org. g. For For Annual  Annual Book of ASTM   volume information, refer to the standard’s Document Summary page on Standards volume Standards the ASTM website website..

3 Available from U.S. Government Printing Office Superintendent of Documents, 732 N. Capito Capitoll St., NW, Mail Stop: SDE, Washington, Washington, DC 20401 20401.. 4 America rican n  Reagent Chemicals, American Chemical Society Specification Specificationss , Ame Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see   Analar Standards for Laboratory Chemicals,, BDH Ltd., Poole, Dorset, U.K., and the  United States Pharmacopeia Chemicals and National Formulary, Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

1

D 1726 – 03 11. Calculation

sufficiently high purity to permit its use without lessening the accuracy of the determination. 7.2  Purity of Water —Unless —Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to Type II of Specification D 1193.

11.1 11 .1 Calculate Calculate the weigh weightt perc percent ent hydr hydrolyza olyzable ble chlo chloride ride content of the specimen as follows:  H  5  [ ~V  2 W   2  B ! N  3  3  3.55]/ W 

(1)

where:  H  = weight weight perce percent nt hydr hydrolyza olyzable ble chlor chloride, ide,  B = HCl requi required red for for titra titration tion of the the blank, blank, mL, V  = HCl requir required ed for titr titratio ation n of the the hydrolyz hydrolyzed ed specispecimen, mL, = norm normalit ality y of the HCl,  N  gramss of chlor chlorine ine per milliequi milliequivalen valentt multiplied multiplied by 3.55 = gram the percentage factor of 100, and W  = speci specimen men weigh weight, t, g.

TEST METHOD A – 1 Weight % and Below of  Hydrolyzable Chloride 8. Reage Reagents nts and Materials Materials 8.1   Hydrochloric Acid, Standard   (0.1 N )—Dilute )—Dilute 9 mL of  concentrated hydrochloric acid (HCl, sp gr 1.19) to 1 L with water wat er.. Sta Standa ndardi rdize ze aga agains instt 0.2 0.25 5 g of sod sodium ium car carbon bonate ate (Na2CO3) accurately weighed and dissolved dissolved in 75 to 100 mL of  water. 8.2   Methyl Ethyl Ketone . Phenolphthalein Indicator Solution—D 8.3   Phenolphthalein —Dis isso solv lvee 1 g of  phenolphth pheno lphthalei alein n in 100 mL of meth methanol anol,, ethan ethanol, ol, or isopr isoproopanol. Potassium sium Hydr Hydroxide oxide,, Alcoh Alcohol ol Solut Solution ion   (0.1 N )— 8.4 Potas )— Dissolve 5.5 to 6.0 g of potassium hydroxide (KOH) in 1 L of  methanol (99 %) or ethanol conforming to Formula No. SD-30 of the U.S. Bureau of Internal Revenue. No standardization of  the solution is necessary. 8.5   Toluene (Warning —Seee Sec Sectio tion n 9.) 9.),, con confor formin ming g to Warning—Se Specification D 841. 8.6   Boiling Chips.

12. Prec Precisio ision n 12.1 The following following criteria criteria should be used for judgi judging ng the acceptability of results at the 95 % confidence level: 12.1.1   Repeatability—T —Two wo res result ultss obt obtain ained ed by the sam samee operator should be considered suspect if they differ by more than 0.02 % absolute. 12.1.2   Reproducibility —Two results obtained by operators in different laboratories should be considered suspect if they differ dif fer by more than 0.05 weight weight %. TEST METHOD B – 5-2500 PPM Hydrolyzable Chloride 13. Appar Apparatus atus

9. Hazar Hazards ds

13.1   Reflux Apparatus, consisting of a 250-mL Erlenmeyer flask attached to a reflux condensor. 13.2   Hot Plate, with variable heat control. 13.3  Magnetic Stirrer , with polytetrafluoroethylene (PTFE)coated stirring bar. 13.4   Buret or Automatic Titrator . 13.5   Silver Electrode   or equivalent. 13.6   Boiling Chips.

9.1 Consult the latest OSHA regulations, supplier’s Material Data Sheets, and local regulations regarding all materials used in this method. 9.2 Hydro Hydrochlo chloric ric acid and potassium potassium hydroxide hydroxide are corrosive. Toluene and methyl ethyl ketone are flammable and their vapors can be harmful. Precautions should be taken to avoid inhalation and skin or eye contact with these chemicals. All sample preparations should be done in a well ventilated area, such as a fume hood.

14. Reage Reagents nts and Material Material 14.1   Acetone, (Warning —See Section 15.) conforming to Warning—See Specification D 329. Bromcr cresol esol Gre Green en Indi Indicator cator Solu Solution tion (0.1 %)— 14.2   Brom Dissolve 0.1 g of bromcresol green in 100 mL of water. 14.3   Nitric acid , (HNO3) (1 + 1) diluted with water. Potassium Hydr Hydroxide oxide, al 14.4   Potassium alcoh cohol ol so solut lution ion (0 (0.1 .1 N )— )— Dissol Dis solve ve 5.6 g of pot potass assium ium hydroxi hydroxide de (KO (KOH) H) in 1 mL of  methanol (99 %) or ethanol conforming to Formula No. SD-30 of the US Bureau of Internal Revenue. No standardization of  the solution is necessary. 14.5   Silver Nitrate , alcohol solution (0.0025 N )—Dissolve )—Dissolve 0.425 g of silver nitrate (AgNO 3), weighed to the nearest 1 mg, in 1 L of methanol (99 %) or ethanol conforming to Formula No. SD-30 of the US Bureau of Internal Revenue. Standardize against agai nst hydr hydrochlo ochloric ric acid or sodiu sodium m chlor chloride ide solut solution ion (wit (with h traceability to an NIST standard). 14.6   Toluene, (Warning —See Section 15.) conforming to Warning—See Specification D 841. 14.7   Glaci —Seee Sec Sectio tion n 15. 15.)) Glacial al Ace Acetic tic Aci Acid  d , (Warning Warning—Se conforming to Specification D 3620.

10. Proc Procedur eduree 10.1 Weigh to the nearest 1 mg, 6 to 8 g of neutral specimen specimen into a 250-mL glass-stoppered Erlenmeyer flask. By means of  a pipette, transfer 50.0 mL of 0.1 N  alcoholic KOH solution into the flask and add 15 mL of toluene. Stopper the flask and swirl to mix. Add a few boiling aids and attach to the reflux condenser on the hot plate. 10.2 Allo Allow w the solution solution to reflux gently for 15  6  1 min. At the end of the reflux period, remove the flask from the hot plate and cool to room temperature with the condenser in place. 10.3 Remove the condenser, condenser, add 3 drops of phenolphthalein phenolphthalein indicator solution to the specimen, and titrate with 0.1  N  HCl. The end point is taken when 1 drop changes the solution from pink to colorless. NOTE  1—Add 100 mL of methyl ketone to the specimen if required to ensure a hom ensure homoge ogeneo neous us solu solution tion during titration titration of the exc excess ess KOH solution.

10.4 Make a blank determina determination tion on the reag reagents ents following following the same procedure but omitting the specimen. 2

D 1726 – 03 15. Haza Hazards rds

16.6 Tit Titrate rate with 0.0025 0.0025  N  silver nitrate using the combination silver electrode and the automatic titrator or buret. 16.7 Reflux a blank, which includes includes all compo component nentss except the sample, and titrate with 0.0025 N  silver   silver nitrate.

15.1 Consult the latest OSHA regulations, supplier’s supplier’s Material Data Sheets, and local regulations regarding all materials used in this method. 15.2 Nitr Nitric ic acid acid,, glac glacial ial acetic acid, potassium potassium hydro hydroxide xide,, and sil silver ver nit nitrat ratee are cor corros rosive ive.. Ace Aceton tonee and tol toluen uenee are flammable and their vapors can be harmful. Precautions should be taken to avoid inhalation and skin or eye contact with these chemicals. All sample preparations should be done in a well ventilated area, such as a fume hood.

17. Calculation 17.1 Calcu Calculate late the parts per mill million ion hydr hydrolyza olyzable ble chloride content of the specimen as follows:  2  B ! N  3  3  35.5 3  10 3# / W   H  5  [ ~V  2 W 

where:  H   B

16. Proc Procedur eduree 16.1 Weigh 2 to 3 g of specimen, to the nearest 0.005 g, into a 250-mL Erlenmeyer flask. Add 20 mL of toluene, 20 mL of  acetone, and 50 mL of 0.1  N  alcoholic  alcoholic KOH. Swirl or mix until dissolution is complete. 16.2 16. 2 Add several several boi boilin ling g chi chips, ps, con connec nectt the flask to the reflux condenser, and gently reflux for 15 6   1 min on a hot plate. 16.3 Remo Remove ve the hot plat platee from under the flask and allow the flask and contents to cool to room temperature. Rinse down the condenser with acetone then remove from the flask. 16.4 16. 4 Qua Quanti ntitat tative ively ly tra transf nsfer er the contents contents of the flask to a 250-m 250 -mL L bea beaker ker usi using ng ace aceton tonee as was wash h sol soluti ution. on. Dil Dilute ute the solution to about 125 mL with acetone, insert a stirring bar, bar, and place on a magnetic stirrer. 16.5 Add five drops of brom bromcreso cresoll gree green n indi indicator cator.. Whil Whilee stirring add 1 + 1 nitric acid dropwise just until the permanent color changes from blue to yellow. Also, 50 mLs of glacial acetic ace tic acid can be add added ed ins instea tead d of add adding ing the nit nitric ric acid dropwise (glacial acetic acid is not as strong as nitric acid). (Warning —If you are using nitric acid, do not add an excess Warning—If amount. Do not acidify the solution until ready to begin the titration. Make certain that the solution is at room temperature before acidifying. These cautions are necessary to prevent the chloride results from being low due to recombination with the resin.)

V   N  35.5 3  103 W 

= part partss per mill million ion hydro hydrolyza lyzable ble chlo chloride, ride, = Ag AgNO NO3 required for the titration of the blank, mL, = Ag AgNO NO3   required for the titration of the hydrolyzed specimen, mL, = Norma Normality lity of the AgNO3, = grams of chlorine chlorine per mill milliequ iequivale ivalent nt multiplied by the ppm conversion of 1  3  10 6, and = speci specimen men weigh weight, t, g.

18. Prec Precisio ision n 18.1 A liquid epoxy epoxy resin of approximately 150 ppm hydrohydrolyzable chloride was sampled and analyzed at five laboratories and seven analysts obtained the following results. 18.1.1   Repeatability—The dif differe ference nce betwe between en two resu results lts obtained by the same analyst should not vary by more than 8.32 % at the 95 % confidence level. 18.1.2   Reproducibility —Th —Thee dif differ ferenc encee bet betwee ween n two results, sul ts, eac each h the mea mean n of two det determ ermina inatio tions, ns, obt obtain ained ed by analysts in different laboratories should not vary by more than 15.88 % relative at the 95 % confidence level. 19. Keyw Keywords ords 19.1 hydrolyzable chloride; chloride; liquid epoxy resin; saponifiable saponifiable chloride

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned  in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk  of 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 and  if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards  and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the  responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should  make 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 19428-2959, United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above  address add ress or at 610 610-832 -832-95 -9585 85 (ph (phone one), ), 610 610-83 -832-95 2-9555 55 (fax (fax), ), or serv service ice@as @astm.o tm.org rg (e-m (e-mail ail); ); or thro through ugh the AST ASTM M web websit site  e  (www.astm.org).

3