Designation: D 1847 – 93 (Reapproved 1998)
Standard Test Methods for
Total Chlorine Content of Epoxy Resins 1 This standard is issued under the fixed designation D 1847; 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
5. Purit Purity y of Reagents
1.1 These test methods methods cover the determinati determination on of the total chlorine content, in concentrations below 1 weight percent, of epoxy resins. Both organic and inorganic chlorine compounds contained in the resin are determined. Epoxy resin is defined as the reaction product of a chlorohydrin and a di- or polyfunctional phenolic compound. 1.2 Two alte alternat rnative ive test methods for deter determini mining ng chlo chloride ride ion concentration resulting from combustion of the sample are included as follows:
5.1 Reagent Reagent gra grade de che chemic micals als sha shall ll be use used d in all tests. tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagen Rea gents ts of the Ame Americ rican an Che Chemic mical al Soc Societ iety y, whe where re suc such h 3 specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. 5.2 Unless otherwise indicated, indicated, references to water water shall be understood to mean reagent water conforming to Type II of Specification D 1193.
Test Method A—Potentiometric Titration Test Method B—Gravimetric Determination
Sections 6-10 11-15
TEST METHOD A—POTENTIOMETRIC TITRATION
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.
6. Appa Apparatus ratus 6.1 Combustion Apparatus—An oxygen bomb4 apparatus for combustion of the sample. 6.2 Titration suitab table le pH met meter er equ equipp ipped ed Titration Apparatus—A sui with a glass-silver electrode system and titration stand, stirrer, beakers, and 10-mL buret.
2. Referenced Documents 2.1 ASTM Standards: D 1193 1193 Specification for Reagent Water2
7. Reag Reagents ents
3. Summa Summary ry of Test Method
7.1 Meth alcoho oholl sol soluti ution) on)— — Methyl yl Red Ind Indica icator tor (0.2 % alc Dissolve 0.2 g of methyl red in 100 mL of methanol, ethanol or isopropanol. Nitric Aci Acid d (sp gr 1.4 7.2 Nitric 1.42)— 2)—Con Concen centra trated ted nit nitric ric aci acid d (HNO3). 7.3 Oxygen, fre freee of com combus busti tible ble mat materi erials als and hal haloge ogen n compounds, available at a pressure of 40 atm. 7.4 Silver Nitrate, Standard Solution (0.01 N )—Dissolve )—Dissolve in water 1.70 6 0.01 g of crystalline silver nitrate (AgNO 3) which
3.1 The resin is oxidized oxidized by combustion combustion in a bomb containcontaining oxy oxygen gen und under er pre pressu ssure. re. The chl chlori orine ne com compou pounds nds thu thuss liberated are absorbed in a sodium carbonate solution. In Test Method Met hod A the amo amount unt of chl chlori orine ne pre presen sentt is det determ ermine ined d by potentiometric titration with standard silver nitrate solution. In Test Method B the amount of chlorine present is determined gravimetrically by precipitation as silver chloride. 4. Signi Significanc ficancee and Use 4.1 The total chlorine chlorine content content of epoxy resins resins is an imporimportantt var tan variab iable le in det determ ermini ining ng rea reacti ctivit vity y of epo epoxy xy res resins ins and perfor per forman mance ce of coa coatin tings gs pre prepar pared ed fro from m the them. m. The These se tes testt methods may be used to determine the total chlorine content of manufactured epoxy resins to confirm specification limits.
3 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. 4 The sole sou source rce of sup supply ply of the dou doubleble-val valve, ve, self self-sea -sealin ling g oxy oxygen gen bom bomb b equipped with a safety-relief-type oxygen filling connection, ignition circuit, fuse wire, sample cups, and water bath, known to the committee at this time is Parr Instrument Co., 209 53rd St., Moline, IL 61265. If you are aware of alternative suppliers, please provide this information to ASTM Headquarters. Your comments willl rece wil receive ive care careful ful con consid siderat eration ion at a meet meeting ing of the resp respons onsibl iblee tech technic nical al committee,1 which you may attend.
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These test methods are under the jurisdiction of ASTM Committee D-1 on Paint and Related Coatin Coatings, gs, Materials, and Applic Applications ations and are the direct respon responsibility sibility of Subcommittee D 01.33 on Polymers and Resins. Currentt editio Curren edition n approv approved ed April 15, 1993. Published June 1993. Originally Originally published publis hed as D 1847 – 61 T. T. Last previous edition D 1847 – 87. 2 Annual Book of ASTM Standard Standardss, Vol 11.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 1847 1847 – 93 93 (19 (1998) 98) previously has been pulverized, dried at 150°C for 1 h, and stored in a glass-stoppered bottle, and dilute to 1 L. Standardize agains aga instt an acc accura uratel tely y wei weighe ghed d amo amount unt of sod sodium ium chl chlori oride de (NaCl) dissolved in 75 to 100 mL of water. 7.5 Sodium Carbonate Solution (20 g/L)—Dissolve 20 g of sodium carbonate (Na 2CO3) in water and dilute to 1 L.
When the rate of change of cell potential becomes greater than 5 mV per 0.1 mL, use 0.1-mL increments of 0.01 N AgNO AgNO3 solution. 8.2.4 Conti Continue nue the titration titration until the rate of chan change ge of cell potential is less than 2 mV per 0.1 mL of AgNO 3 solution. Remove Remo ve the titrated solution, solution, rins rinsee the electrodes electrodes well with water, wipe with a dry cloth, and burnish the silver electrode lightl lig htly y wit with h a fine eme emery ry clo cloth. th. Bet Betwee ween n det determ ermina inatio tions, ns, immerse the electrodes in water. 8.2.5 Plot the cumulati cumulative ve volumes volumes of 0.1 N AgNO AgNO3 solution added against the corresponding cell potentials. Select as the end point the mid midway way point on the steepest steepest portion portion of the inflection curve. 8.2.6 Make a blank determination determination in accordance with 8.2.18.2.4, 8.2 .4, but omi omitt the spe specim cimen. en. This pro proced cedure ure wil willl giv givee a measure of the chlorine in the reagents used.
8. Proc Procedur eduree 8.1 Combustion of Specimen: 8.1.1 Place 25 25 mL of Na2CO3 solution in the bottom of the bomb. Incline the bomb and rotate it in such a manner that the interior surface is moistened by the solution. 8.1.2 Weigh to 1 mg 0.8 to 1.2 g of sample into into the metal sample cup. Grind solid resins to pass a No. 60 (250-µm) sieve and moisten with a few drops of acetone before combustion. 8.1.3 8. 1.3 Inser Insertt th thee cu cup p co cont ntai aini ning ng th thee sa samp mple le in th thee lo loop op electr ele ctrode ode and att attach ach the fus fusee wir wiree so tha thatt it han hangs gs sli slight ghtly ly above the specimen. Assemble the bomb and tighten the cover securely; secur ely; however, however, do not use auxiliary auxiliary tool toolss to tighten the cover. 8.1.4 8.1 .4 Att Attach ach the fill filling ing con connec nectio tion n to the oxy oxygen gen-fil -fillin ling g valve and admit oxygen slowly (to avoid blowing the sample from the cup) until a pressure of 35 atm is indicated on the gage; then close the control valve. Open the relief valve to redu re duce ce th thee pr pres essu sure re in th thee tu tube be an and d in th thee co conn nnec ecti tion on to atmospheric pressure. Detach the filling connection from the bomb and replace with the bomb thumb nut. Tighten the thumb nut with finger pressure. 8.1.5 Imme Immerse rse the bomb in the water bath, bath, then connect the terminals to the electrical circuit. Ignite the charge within the bomb by closing the switch for not more than 5 s, or until the pilot light goes out. Allow the bomb to stand in the water bath for 10 min while cooling. 8.1.6 Remov Removee the bomb from the water bath, and invert and rotate rot ate it so tha thatt max maximu imum m was washin hing g of the inside inside sur surfac facee is achieved. Release the pressure at a uniform rate over a period of not less than 1 min. 8.2 Titration: 8.2.1 Tra Transfe nsferr the absorbing absorbing solut solution ion from the combustion combustion of the sample to a 250-mL tall-form titration beaker. Wash all the inside surfaces of the bomb with a fine stream of water and transfer the washings to the beaker. Adjust the volume of the soluti sol ution on to 150 to 200 mL wit with h wat water er.. Add thr three ee dro drops ps of methyl red indicator solution and neutralize with HNO 3; then add 6 drops in excess. 8.2.2 Place the beaker on the titration titration stand and adjust its position so that the electrodes are about half immersed. Fill the buret bur et wit with h 0.0 0.01 1 N AgNO3 soluti solution, on, and place the bur buret et in posit pos ition ion on the tit titrat ration ion ass assemb embly ly so tha thatt the tip ext extend endss approximately 25 mm below the surface of the liquid in the beaker. Adjust the speed of the stirrer to give vigorous stirring without witho ut spla splatter ttering. ing. Recor Record d the initial buret and mete meterr (cel (celll potential) readings. 8.2.3 8.2 .3 Add small portions portions of 0.0 0.01 1 N AgNO3 solution and, after waiting until a constant potential has been established, record rec ord the bur buret et and me meter ter rea readin dings. gs. In reg region ionss bet betwee ween n infle in flect ctio ions ns wh wher eree th thee po pote tent ntia iall ch chan ange ge is sm smal alll fo forr ea each ch increment incre ment of AgNO3 solution, add volumes as large as 0.5 mL.
9. Calc Calculat ulation ion 9.1 Calculate the chlorine content content of the sample as follows: Chlorine, % 5 [~V 2 B! N 3 0.0355/ S S] 3 100
(1)
where: V = AgNO AgNO3 solution required for titration of the specimen, mL B = AgNO AgNO3 solution required for titration of the blank, mL N = norm normalit ality y of the AgNO3 solution, and S = spec specimen imen weigh weightt used, used, g. 10. Prec Precisio ision n 10.1 The following following criteria criteria should be used for judgi judging ng the acceptability of results at the 95 % confidence level. 10.1.1 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 weight %. 10.1.2 Reproducibility —The results, each the mean of two determinations, obtained by operators in different laboratories should be considered suspect if they differ by more than 0.05 weight %. TEST METHOD B—GRAVIMETRIC DETERMINATION 11. Apparatus 11.1 Combustion Apparatus—See 6.1. 11.2 Fritted-Glass, medium porosity. 12. Reage Reagents nts 12.1 Warning— 1.42)—Conc —Concentr entrated ated Warning— Nitric Acid (sp gr 1.42) nitric acid (HNO3). 12.2 Caution— 99)— )—Mi Mix x 1 vo volu lume me of Caution— Nitric Acid (1 + 99 HNO3(sp gr 1.42) with 99 volumes of water. 12.3 Oxygen—See 7.3. 12.4 Potassium Iodide Solution (300 g/litre)—Dissolve 300 g of potassium iodide (KI) in water and dilute to 1 L. 12.5 Silver Nitrate Solution (100 g/L)—Dissolve 100 g of silver nitrate (AgNO 3) in water and dilute to 1 L. 12.6 Silver Nitrate, Standard Solution (0.01 N )—See )—See 7.4. 12.7 Sodium Carbonate Solution (20 g/L)—See 7.5. 2
D 1847 1847 – 93 93 (19 (1998) 98) 13. Proc Procedur eduree
14. Calculation
13.1 Oxidi Oxidize ze the specimen specimen by combu combustio stion n in acco accordanc rdancee with 8.1.1-8.1.6.
14.1 14. 1 Cal Calcul culate ate the chl chlori orine ne con conten tentt of the spe specim cimen en as follows:
13.2 Transfer the the absorbing solution from the the combustion of the specimen to a 250-mL beaker. Wash all the inside surfaces of th thee bo bomb mb wi with th a fin finee st stre ream am of wa wate terr an and d tr tran ansf sfer er th thee washings to the beaker. Add 1 mL of HNO 3(sp gr 1.42) to the solution; then, with stirring, add 1 mL of AgNO 3 solution (100 g/L). Heat the solution to boiling as rapidly as possible. Allow the mixture to cool in a dark cabinet for at least 1 h.
Chlorine, % 5 [~P 2 B! 3 0.2474/ S S] 3 100
(2)
where: P = AgCl precipi precipitate tate from from the the specimen specimen,, g, B = AgC AgCll found found in the the blank blank,, g, and S = spe specim cimen en use used, d, g. 15. Prec Precisio ision n and Bias 15.1 The following following criteria criteria should be used for judgi judging ng the acceptability of results at the 95% confidence level. 15.1.1 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 0.05 weight percent. 15.1.2 Reproducibility —Two results, each the mean of two determinations, obtained by operators in different laboratories should be considered suspect if they differ by more than 0.05 weight percent. 15.2 Bias—No bia biass can be det determ ermine ined d sin since ce no sta standa ndard rd epoxy resin exists.
13.3 Filter the precipitate precipitate by suction on a clean, fritted-glass fritted-glass filter filt er fun funnel nel.. Wash the sil silver ver chl chlori oride de (Ag (AgCl) Cl) pre precip cipita itate te thoroughly with HNO3(1 + 99). Dry the filter and precipitate at 110°C for 1 h. Cool in a desiccator and weigh accurately to 0.1 mg. 13.4 Diss Dissolve olve the AgCl from the filter, filter, using KI solut solution. ion. Wash the filter thoroughly with HNO 3 (1 + 99). Dry the filter at 110°C for 1 h, cool in a desiccator, and reweigh. The weight of AgCl obtained from the sample is the difference between the weight of the filter funnel containing the precipitate and the weight of the filter funnel obtained at this time. 13.5 Make a blan blank k deter determina mination tion in acco accordanc rdancee with 13.2 and 13.4, but omit the specimen. This procedure will give a measure of the chlorine in the reagents used.
16. Keyw Keywords ords 16.1 chlorine; chlorine content; content; epoxy; oxygen bomb; total total chlorine
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