1、Designation: D 1439 03Standard Test Methods forSodium Carboxymethylcellulose1This standard is issued under the fixed designation D 1439; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenth
2、eses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the testing of sodium car-boxymethylcellulose.1.2 The test procedures appear in the following order:SectionsMoisture 4-9Degree
3、 of Etherification:Test Method AAcid Wash 10-17Test Method BNonaqueous Titration 10, 11, 18-23Viscosity 24-30Purity 31-38Sodium Glycolate 39-47Sodium Chloride 48-55Density 56-621.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonl
4、y.1.4 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. For specific
5、 hazardstatements, see 15.1 and 20.2. Referenced Documents2.1 ASTM Standards:2D 1347 Test Methods for Methylcellulose3E1 Specification for ASTM Liquid-in-Glass Thermometers3. Purity of Reagents3.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all
6、reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society4, where suchspecifications are available. Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening
7、 the accuracy ofthe determination.3.2 Unless otherwise indicated, references to water shall beunderstood to mean distilled water.MOISTURE4. Scope4.1 This test method covers the determination of the volatilecontent of sodium carboxymethylcellulose.4.2 The results of this test are used for calculating
8、 the totalsolids in the sample; and, by common usage, all materialsvolatile at this test temperature are designated as moisture.5. Significance and Use5.1 Moisture analysis (along with purity) is used to calculatethe amount of active polymer in the material and must beconsidered when determining the
9、 amount of sodium carboxym-ethylcellulose to use in various formulations.6. Apparatus6.1 OvenGravity convection oven, capable of maintain-ing a temperature of 105 6 3C.6.2 Weighing Bottles, low-form, 50-mm inside diameter by30-mm height, or equivalent.6.3 Analytical Balance.7. Procedure7.1 Weigh3to5
10、gofthesample to the nearest 0.001 g in atared and covered weighing bottle.7.2 Place the bottle in an oven at 105C for 2 h with thecover removed. Cool the bottle in a desiccator, replace thecover, and weigh.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coati
11、ngs, Materials, and Applications and are the directresponsibility of Subcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved Dec. 1, 2003. Published January 2004. Originallyapproved in 1956. Last previous edition approved in 1997 as D 1439 97.2For referenced ASTM standard
12、s, 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 website.3Withdrawn.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical
13、Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville
14、,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.3 Replace the sample in the oven for 30 min, cool, andreweigh.7.4 Continue this procedure to a mass loss of not more than5 mg for 30 min drying time.8. Calculation8.1 Calculate th
15、e percent moisture, M, as follows:M 5 A/B! 3 100 (1)where:A = mass loss on heating, g, andB = sample used, g.9. Precision and Bias9.1 PrecisionStatistical analysis of interlaboratory repro-ducibility test results on samples containing 2 to 10 % moistureindicates a precision of 60.2 % absolute at the
16、 95 % confi-dence level.9.2 BiasNo justifiable statement can be made on the biasof the procedure for measuring moisture because no suitablereference material exists.DEGREE OF ETHERIFICATION10. Scope10.1 These test methods cover the determination of thedegree of etherification (D.E.) of sodium carbox
17、ymethylcellu-lose.10.2 Two test methods are included as follows:10.2.1 Test Method A (Acid Wash), for crude grades ofsodium carboxymethylcellulose with degrees of etherificationup to 0.85. Above 0.85 degree of etherification, slightly lowresults may be obtained.10.2.2 Test Method B (Nonaqueous Titra
18、tion), for purifiedgrades of sodium carboxymethylcellulose of all degrees ofetherification. It is not applicable to the crude grades.Test Method AAcid Wash11. Summary of Test Method11.1 The water-soluble sodium carboxymethylcellulose isconverted to the insoluble acid form, purified by washing,dried,
19、 and then a weighed sample is reconverted to the sodiumsalt with a measured excess of sodium hydroxide.12. Significance and Use12.1 These test methods determine the amount of substitu-ent groups added to the cellulose backbone. The level cangreatly affect solution properties, rheology, viscosity, hy
20、gro-scopicity, salt tolerance, and many other properties of thepolymer.13. Apparatus13.1 Stirrer, air-driven.13.2 Buchner Funnel, 75-mm, fitted with a 70-mm fine-texture, heavy-duty filter paper. A 60-mm medium-porosity,fritted glass funnel may also be used.13.3 Drying Oven, maintained at 105C.14. R
21、eagents14.1 Diphenylamine ReagentDissolve 0.5 g of dipheny-lamine in 120 mL of sulfuric acid (H2SO4, 9 + 2). The reagentshould be essentially water-white. It will give a deep bluecoloration with traces of nitrate or other oxidizing agents.14.2 Ethyl Alcohol (95 volume %)Denatured ethyl alco-hol conf
22、orming to either Formula 2B, 3A, or 30 of the U. S.Bureau of Internal Revenue.14.3 Ethyl Alcohol (80 % by volume)Dilute 840 mL ofFormula 2B, 3A, or 30 denatured alcohol to 1 L with water.14.4 Hydrochloric Acid, Standard (HCl, 0.3 to 0.5 N).14.5 Methanol, anhydrous.14.6 Nitric Acid (sp gr 1.42)Concen
23、trated nitric acid(HNO3).14.7 Sodium Hydroxide, Standard Solution (0.3 to 0.5 N)Prepare and standardize a 0.3 to 0.5 N solution of sodiumhydroxide (NaOH).14.8 Sulfuric Acid (9 + 2)Carefully mix 9 volumesH2SO4with 2 volumes of water.15. Procedure15.1 Weigh approximately4gofthesample into a 250-mLbeak
24、er and add 75 mL of ethyl alcohol (95 %). Stir the mixturewith an airdriven stirrer until a good slurry is obtained. Add 5mL of HNO3, while agitating, and continue agitation for 1 to 2min. Heat the slurry and boil for 5 min. (WarningExercisecare to avoid fire.) Remove the heat and continue agitation
25、 for10 to 15 min.15.2 Decant the supernatant liquid through the filter andtransfer the precipitate to the filter with 50 to 100 mL of ethylalcohol (95 %). Wash the precipitate with ethyl alcohol (80 %)that has been heated to 60C, until all of the acid has beenremoved.15.3 Test for the removal of aci
26、d and salts (ash) by mixinga drop of the acid carboxymethylcellulose slurry from the filterwith a drop of diphenylamine reagent on a white spot plate. Ablue color indicates the presence of nitrate and the necessity forfurther washing. If the first drop of reagent does not produce ablue color, furthe
27、r drops should be added until an excess ofreagent is known to be present, noting the color after each drop.Four to six washings will usually suffice to give a negative testfor nitrate.15.4 Finally, wash the precipitate with a small amount ofanhydrous methanol and draw air through it until the alcoho
28、l iscompletely removed. Transfer the precipitate to a glass oraluminum weighing dish provided with a cover. Heat theuncovered dish on a steam bath until the odor of alcohol can nolonger be detected (in order to avoid fires due to methanolfumes in the oven), then dry the dish and contents, uncoveredf
29、or3hat105C. Place the cover on the dish and cool to roomtemperature in a desiccator.15.5 The sulfate ash content of the sample at this pointshould be less than 0.5 % when determined on 0.5 g of thesample by the procedure given in the Ash as Sulfate section ofTest Methods D 1347. If the ash content i
30、s greater than 0.5 %,rewash the sample with ethyl alcohol (80 %). If necessary,repeat the procedure described in 13.1-13.3 to 13.4.15.6 Weigh, to the nearest 0.01 g, about 1 to 1.5 g of thedried acid carboxymethylcellulose (depending on the normal-ity of the acid and base to be used) into a 500-mL E
31、rlenmeyerflask. Add 100 mL of water and 25.00 mL of 0.3 to 0.5 ND1439032NaOH solution, while stirring. Heat the solution to boiling, andboil for 15 to 30 min.15.7 Titrate the excess NaOH, while the solution is hot, withthe 0.3 to 0.5 N HCl to a phenolphthalein end point.16. Calculation16.1 Calculate
32、 the degree of etherification, G, as follows:A 5 BC DE!/F (2)G 5 0.162A/1 0.0584A! (3)where:A = milliequivalents of acid consumed per gram ofsample,B = NaOH solution added, mL,C = normality of the NaOH solution,D = HCl required for titration of the excess NaOH, mL,E = normality of the HCl,F = acid c
33、arboxymethylcellulose used, g,162 = gram molecular mass of the anhydroglucose unit ofcellulose, and58 = net increase in molecular mass of anhydroglucoseunit for each carboxymethyl group substituted.17. Precision and Bias17.1 PrecisionStatistical analysis of intralaboratory (re-peatability) test resu
34、lts indicates a precision of 60.04 D.E.units at the 95 % confidence level.17.2 BiasNo justifiable statement can be made on the biasof the procedure for measuring degree of etherification becauseno suitable reference material exists.Test Method BNonaqueous Titration18. Summary of Test Methods18.1 Thi
35、s measurement is based upon a nonaqueous acid-base titration. The sample is refluxed with glacial acetic acid,and the resulting sodium acetate is titrated with a standardsolution of perchloric acid in dioxane, to a potentiometric endpoint. Impurities containing alkaline sodium will also betitrated u
36、nder these conditions. Sodium chloride does notinterfere.19. Apparatus19.1 pH Meter, equipped with a standard glass electrode anda calomel electrode modified as follows:19.1.1 Discard the aqueous potassium chloride solution,then rinse and fill with the calomel electrode solution asdescribed in 20.2.
37、19.1.2 Add a few crystals of potassium chloride and silverchloride or silver oxide to the electrode.19.2 Buret, micro, 10-mL capacity.20. Reagents20.1 Acetic Acid, glacial.20.2 Calomel Electrode SolutionAdd2gofpotassiumchloride (KCl) and2gofsilver chloride (AgCl) or silver oxide(Ag2O) to 100 mL of m
38、ethanol and shake thoroughly tosaturate. Use the supernatant liquid.20.3 1,4-Dioxane.20.4 Perchloric Acid (0.1 N)Add 9 mL of concentratedperchloric acid (HClO4, 70 % to 1 L of dioxane, with stirring(WarningThe solution of perchloric acid in dioxane shouldnever be heated or allowed to evaporate.). St
39、ore in an amberglass bottle. Any slight discoloration that appears on standingmay be disregarded.20.4.1 Standardize the solution as follows: Dry potassiumacid phthalate for2hat120C. Weigh 2.5 g to the nearest0.0001 g into a 250-mL volumetric flask. Add glacial aceticacid, shake to dissolve, and then
40、 make up to volume and mixthoroughly. Pipet 10 mL into a 100-mL beaker and add 50 mLof acetic acid. Place on a magnetic stirrer and insert theelectrodes of the pH meter. Add nearly the required amount ofHClO4from a buret, then decrease the increments to 0.05 mLas the end point is approached. Record
41、the millilitres of titrantversus millivolts, and continue the titration a few millilitresbeyond the end point. Plot the titration curve and read thevolume of titrant at the inflection point. Calculate the normal-ity, N, as follows:N 5 A 3 10 3 1000!/B 3 204.22 3 250! (4)where:A = potassium acid phth
42、alate used, g,B = HClO4added, mL,204.22 = gram molecular mass of potassium acid phtha-late,10 = potassium acid phthalate solution added, mL,and250 = glacial acetic acid used to dissolve potassiumacid phthalate, mL.20.5 Potassium Acid Phthalate, primary standard, NationalInstitute of Standards and Te
43、chnology Standard Sample No.84.21. Procedure21.1 Weigh 0.2 g of the sample, to the nearest 0.0001 g, intoa 250-mL Erlenmeyer flask with ground-glass joint. Add 75mL of acetic acid, connect to a water-cooled condenser, andreflux gently on a hot plate for 2 h.21.2 Cool, and transfer the solution to a
44、250-mLbeaker withthe aid of 50 mL of acetic acid. Place on the magnetic stirrerand titrate to a potentiometric end point with 0.1 N HClO4inaccordance with 20.4.22. Calculation22.1 Calculate the degree of etherification, H, as follows(Note 1):M 5 AN 3 100!/G 3 100 2 B! (5)H 5 0.162 M/1.000 0.080 M! (
45、6)where:M = milliequivalents of acid consumed per gram ofsample,A = HClO4added, mL,N = normality of HClO4,G = sample used, g,B = percent moisture, determined on a separate sample,in accordance with Sections 4-7,D1439033162 = gram molecular mass of an anhydroglucose unit ofcellulose, and80 = net incr
46、ease in molecular mass of an anhydroglu-cose unit for each sodium carboxymethyl groupadded.NOTE 1The result calculated in accordance with Section 18 includesthe alkaline sodium from sodium glycolate; however, if the latter is lessthan 0.5 %, the interference is negligible.23. Precision and Bias23.1
47、PrecisionStatistical analysis of interlaboratory testresults indicates the precision of this test method as shownbelow:ApproximateD.E. LevelPrecision, D.E. Units(95 % Confidence Level)0.40 60.0100.80 60.0121.35 60.03823.2 BiasNo justifiable statement can be made on the biasof the procedure for measu
48、ring degree of etherification becauseno suitable reference material exists.VISCOSITY24. Scope24.1 This is an arbitrary test method for determining theviscosity of aqueous solutions of sodium carboxymethylcellu-lose in the viscosity range from 10 to 10 000 cP at 25C.24.2 The concentration to be used
49、for the test should beagreed upon between the purchaser and the seller. It should besuch that the viscosity of the solution will fall within the rangeof this test.24.3 The results for the viscosity of sodium carboxymeth-ylcellulose by this test method will not necessarily check withresults from other types of instruments used for viscositymeasurements.24.4 The determinations are run on a calculated dry basis;that is, the amount of sodium carboxymethylcellulose requiredfor the desired concentration on a dry basis is calculated fromthe know
