1、Designation: D 914 00 (Reapproved 2006)Standard Test Methods forEthylcellulose1This standard is issued under the fixed designation D 914; 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 parent
2、heses indicates the year of last reapproval. Asuperscript epsilon (e) 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 testing of ethylcellulose.1.2 The test p
3、rocedures appear in the following order:SectionsMoisture 4 to 6Sulfated Ash 7 to 11Chlorides (as Sodium Chloride) 12 to 16Ethoxyl Content 20 to 24Viscosity 25 to 391.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This st
4、andard may involve hazardous materials, opera-tions, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applic
5、ability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 362 Specification for Industrial Grade Toluene3D 446 Specifications and Operating Instructions for GlassCapillary Kinematic ViscometersD 841 Specification for Nitration Grade TolueneD 4794 Test Method for Det
6、ermination of Ethoxyl or Hy-droxyethoxyl Substitution in Cellulose Ether Products byGas ChromatographyE1 Specification for ASTM Liquid-in-Glass Thermometers3. Purity of Reagents and Materials3.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, all of the reagents used s
7、hallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.4Where such specifications havenot been established, reagents of the best grade available shallbe used. References to water shall be understood to meandis
8、tilled water.MOISTURE4. Scope4.1 This test method covers the determination of the volatilecontent of ethylcellulose.5. Significance and Use5.1 The results of this test are used for calculating the totalsolids in the sample and, by common usage, all materialsvolatile at this test temperature are desi
9、gnated as moisture.5.2 Moisture analysis (along with sulfated ash) is used tocalculate the amount of active polymer in the material and shallbe considered when determining the amount of ethylcellulosein various functions.6. Apparatus6.1 Oven, gravity convection, capable of maintaining atemperature o
10、f 105 6 3C.6.2 Weighing Bottles.6.3 Analytical Balance.7. Procedure7.1 Weigh accurately 2 to5gofthesample to the nearest0.001 g into a tared dish (fitted with a lid) and dry for2hinanoven at 100 to 105C. Remove the dish from the oven, coverwith a lid, cool in a desiccator, and weigh.1These test meth
11、ods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 1947. Last
12、 previous edition approved in 2000 as D 914 00.2For 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 website.3Withdrawn.4Re
13、agent Chemicals, American Chemical Society Specifications, AmericanChemical 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 Pharmacopeiaa
14、nd National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Calculation8.1 Calculate the percent moisture, M as follows:M 5 A/B! 3 100 (1)where:A = mass loss on h
15、eating, g, andB = sample used, g.9. Precision and Bias9.1 PrecisionStatistical analysis of intralaboratory (re-peatability) test results indicates a precision of 65 % at the95 % confidence level.9.2 BiasNo statement of bias can be made as no suitablereference material is available as a standard.SULF
16、ATED ASH10. Scope10.1 This test method covers the determination of theresidue on ignition of ethylcellulose after a specimen has beentreated with sulfuric acid.11. Significance and Use11.1 This test method (along with moisture) is used tocalculate the active polymer in the material. It shall be used
17、when testing ethylcellulose in United States government regu-lated applications. Excessive ash may also affect solutionclarity and film properties.12. Apparatus12.1 Muffle Furnace.12.2 Crucibles, either porcelain, 30mL high, form cracked,platinum.13. Reagent13.1 Sulfuric Acid (sp gr 1.84)Concentrate
18、d sulfuric acid(H2SO4).14. Procedure14.1 Ignite a crucible for 10 to 15 min at 800 6 25C, coolin a desiccator, and weigh to the nearest 0.001 g.14.2 Weigh about5gofsample to the nearest 0.001 g(previously dried for3hat105C) into the crucible. Burn offthe bulk of the carbonaceous material directly ov
19、er a flame.After cooling, add 1 mL of H2SO4in such a way as to moistenthe entire ash; then cautiously heat with the burner to densewhite fumes. Ignite in a muffle furnace at 800 6 25C until allsigns of carbon are gone. Cool in a desiccator and reweigh tothe nearest 0.001 g.15. Calculation15.1 Calcul
20、ate the percent ash (as sulfate), C, as follows:C 5 A/B! 3 100 (2)where:A = ash, g, andB = sample used, g.16. Precision and Bias16.1 PrecisionStatistical analysis of interlaboratory (re-producibility) test results indicates a precision of 610 % at the95 % confidence level.16.2 BiasNo statement of bi
21、as can be made as no suitablereference material is available as a standard.CHLORIDES (as Sodium Chloride)17. Scope17.1 This test method covers the determination of thechloride content of ethylcellulose.18. Significance and Use18.1 Sodium chloride is a major by-product of the ethylcel-lulose manufact
22、uring process. This test is a measure of thepurity of ethylcellulose. Chlorides may also affect solutionproperties.19. Apparatus19.1 Titration pH Meter.19.2 Mercury-Mercurous Sulfate Reference ElectrodeTheelectrode uses a potassium sulfate electrolyte to avoid chloridecontamination from a chloride e
23、lectrolyte.19.3 Silver-Silver Chloride ElectrodeThe electrode iscoated with silver chloride periodically. Prepare the electrodeby polishing with fine steel wool, briefly soaking it in 5 %potassium cyanide solution, and rinsing it with water. Coat theelectrode with silver chloride by electrodepositio
24、n from 0.1 Npotassium chloride solution using a 3-V dry cell and a platinumwire electrode. Connect the silver electrode to the positive poleof the battery and electrolyze for 20 s; then reverse theconnections for 5 s. Repeat these operations twice, and finally,chloridize the silver electrode for 20
25、s at the positive terminal.Store the silver electrode in 0.1 N potassium chloride solution.Rinse the electrode with water and wipe it with a soft tissuebefore each titration.19.4 Salt Bridge for Reference ElectrodeFig. 1 shows oneconfiguration in use. Exact dimensions are not important. Thesalt brid
26、ge is used to keep the reference electrode fromplugging with the ethylcellulose slurry.19.5 Air-Driven Stirrer.20. Reagents20.1 Ethanol (95 volume %), undenatured or speciallydenatured conforming to Formula 2B of the U.S. Bureau ofInternal Revenue.20.2 Ethanol-Distilled Water Solvent Mixture (80 + 2
27、0)Mix 800 g of 2B ethanol with 200 g of water. Add 7.5 g ofaerosol OT 100 % surface-active agent per 3000 g of ethanol-water mixture.20.3 Potassium Nitrate (KNO3) Solution (saturated) for saltbridge (Fig. 1).20.4 Silver Nitrate, Standard Solution (0.02 N)Dissolve3.4 g of silver nitrate (AgNO3) in wa
28、ter, dilute to 1 L withwater in a volumetric flask, and mix. Weigh exactly 0.5845 g ofdry, primary standard sodium chloride (NaCl), dissolve in 25mL of water, and dilute to 1 L with water in a volumetric flask.Add 10 mL of H2SO4(1 + 16) to each aliquot before titrating.D 914 00 (2006)2Titrate aliquo
29、ts of this solution potentiometrically with theAgNO3solution. Calculate the normality, N, of the AgNO3solution as follows:N 5 A/B! 3 0.01 (3)where:A = 0.01 N NaCl solution added, mL, andB = AgNO3solution required for the titration, mL.20.5 Sulfuric Acid (1 + 16)Add 1 volume of concentratedsulfuric a
30、cid (H2SO4, sp gr 1.84) slowly with stirring into 16volumes of water.20.6 Toluene, meeting the requirements of SpecificationD 362.20.7 Toluene-Ethanol Solvent Mixture (90 + 10)Mix 900g of toluene with 100 g of ethanol.21. Procedure21.1 Weigh accurately 10 g of sample to the nearest 0.001 g(previousl
31、y dried for2hat100to105C) and transfer to a600-mL beaker containing 200 mL of the toluene-ethanolsolvent mixture. Stir with an air-driven stirrer until solution iscomplete.21.2 Add 200 mL of the ethanol-water mixture and agitatefor 5 min to form a uniform emulsion. Immerse the electrodesin the emuls
32、ion using an air-driven stirrer for mixing. Add 10mL of H2SO4(1 + 16) and agitate for 3 to 4 min to allow thesystem to reach equilibrium.21.3 Titrate slowly with the 0.02 N AgNO3solution. Makeintermittent additions of 0.1 mL. It is advisable to allow longerperiods of time between additions of titran
33、t as the end point isapproached to avoid passing the equivalence point. Run ablank by the same procedure.22. Calculation22.1 Calculate parts per million of chlorides as NaCl, C,asfollows:C 5 VN 3 0.05845!/W 3 1 000 000 (4)where:V = AgNO3solution, mL,N = normality of AgNO3solution,W = sample used, g,
34、 and0.05845 = milliequivalent mass of NaCl.23. Precision and Bias23.1 PrecisionStatistical analysis of interlaboratory (re-producibility) test results indicates a precision of 65 % at the95 % confidence level.23.2 BiasNo statement of bias can be made as no suitablereference material is available as
35、a standard.ETHOXYL CONTENT24. Scope24.1 This test method covers the determination of theethoxyl content of ethylcellulose.24.2 For an alternative method see Test Method D 4794.25. Significance and Use25.1 This test method determines the amount of substituentgroups added to the cellulose backbone. Th
36、e level can greatlyaffect solution properties, rheology, solubility parameters, andfilm properties.26. Apparatus26.1 Distillation Apparatus, as illustrated in Fig. 2, consist-ing of a boiling flask with a side arm for admission of carbondioxide (CO2) or nitrogen, an air condenser with a trap, and ar
37、eceiver.26.2 Oil Bath, equipped with a heating device, preferablyelectrical, so that the bath can be maintained at 145 to 150C.27. Reagents27.1 Bromine SolutionDissolve 5 mL of bromine in 145mL of the potassium acetate (KC2H3O2) solution. Prepare thebromine solution fresh daily in a hood to remove b
38、rominevapors.27.2 Carbon DioxidePass the CO2through a bubblecounter and a dry trap, and then through a pressure regulatorconsisting of a glass tee whose vertical arm extends almost tothe bottom of a 254-mm (10-in.) column of water. A screwclamp shall be attached to the thin-walled rubber tubingconne
39、cting the horizontal arm of the tee with the boiling flask.This arrangement permits regulation of the flow of gas andallows any excess gas to escape. Nitrogen may be used in placeof CO2.27.3 Formic Acid (90 %).27.4 Gelatin CapsulesGelatin capsules of a suitable sizeto hold from 50 to 60 mg of the dr
40、ied sample will be required.in.mm1320.8183.25167.9389.51212.77822.2112383766152FIG. 1 Salt Bridge and Reference Electrode for ChlorideDeterminationD 914 00 (2006)327.5 Hydriodic Acid (sp gr 1.70)5Hydriodic acid (HI)forms with water a constant-boiling mixture (boiling point 126to 127C) that contains
41、57 % HI. The concentration of HI in thereagent used should be not less than 56.5 %. The blankdetermination, which is affected primarily by free iodine in thereagent, should require no more than 0.5 mL of 0.1 N sodiumthiosulfate (Na2S2O3) standard solution. If necessary, the acidmay be purified by ad
42、ding to it a small amount of redphosphorus and boiling for 20 to 30 min in a hood whilepassing a stream of CO2into the liquid. Distillation is thencarried out behind a safety-glass shield in a hood, using anall-glass apparatus with a slow stream of CO2running throughthe receiver. Under some conditio
43、ns, the poisonous gas phos-phine (PH3) is formed during distillation, and this may unitewith molecular iodine to form phosphorus triiodide (PI3) whichmay explode on contact with air. It is, therefore, advisable tokeep the current of CO2going after the distillation is endedand until the apparatus has
44、 cooled; this will prevent air frombeing sucked into the apparatus. Put the purified HI in small,brown, glass-stoppered bottles, previously swept out with CO2,and seal the stoppers with molten paraffin. Store in a darkplace. To minimize decomposition of HI due to contact withair, run CO2into the bot
45、tle while withdrawing portions of theacid for use.27.6 Phosphorus Slurry (0.06 g/100 mL)Add about 0.06 gof red phosphorus to 100 mLof water. Shake well before using.27.7 Potassium Acetate Solution (100 g/L)Dissolve 100 gof anhydrous potassium acetate (KC2H3O2) crystal in 1 L of asolution containing
46、900 mL of glacial acetic acid and 100 mLof acetic anhydride.27.8 Potassium Iodide (KI).27.9 Sodium Acetate Solution (220 g/L)Dissolve 220 g ofanhydrous sodium acetate in water and dilute to 1 L.27.10 Sodium Thiosulfate, Standard Solution (0.1 N)Dissolve 25 g of sodium thiosulfate (Na2S2O35H2O) in 20
47、0mL of water and dilute to 1 L. Use freshly boiled and cooledwater. It is preferable to allow the solution to stand for a fewdays before standardization. Standardize the solution against0.1000 N potassium dichromate (K2Cr2O7) solution preparedby dissolving exactly 4.9037 g of K2Cr2O7(National Instit
48、uteof Standards and Technology Standard Sample No. 136) inwater and diluting to 1 L in a volumetric flask. By means of aburet, measure accurately 35 to 45 mL of the K2Cr2O7solutioninto a 250-mL Erlenmeyer flask. Add2gofKIand50mLofsulfuric acid (H2SO4, 1 + 9) and allow to stand for about 5 min.Titrat
49、e the liberated iodine with the Na2S2O3solution, usingstarch indicator solution near the end point. At the end point,the blue color of the starch indicator will be destroyed, leavingthe pale green color of the chromate ion. The normality of theNa2S2O3, solution should be checked at least once a week.Calculate the normality, N, of the Na2S2O3solution as follows:N 5 A/B! 3 0.1 (5)where:A = 0.1000 N K2Cr2O7solution added, mL, andB =Na2S2O3solution required for the titration, mL.As an alternative procedure, the Na2S2O3solution may bestandar
