1、Designation: D 1387 89 (Reapproved 2007)Standard Test Method forSaponification Number (Empirical) of Synthetic and NaturalWaxes1This standard is issued under the fixed designation D 1387; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the saponi-fication number of synthetic waxes and natur
3、al waxes.1.2 This test method is applicable to Fischer Tropsche,microcrystalline, polyethylene, and Montan Ester waxes.1.3 Certain synthetic waxes, notably copolymers of ethyl-ene, exhibit poor reproducibility when running saponificationvalues. Reproducibility can be improved if cooking time in 7.2i
4、s extended from3hto1820 h.1.4 Some oxidized polyethylene and other waxes with amelt temperature above 100C may give poor reproducibility.1.5 Some dark-colored (Gardner Color 14) waxes mayobscure the color change of the indicator, resulting in poorreproducibility.1.6 This standard does not purport to
5、 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.2. Referenced Documents2.1 ASTM Standards:2E 200 Pra
6、ctice for Preparation, Standardization, and Stor-age of Standard and Reagent Solutions for ChemicalAnalysis3. Terminology3.1 Definition:3.1.1 saponification numberthe number of milligrams ofpotassium hydroxide required to hydrolyze1gofthesampleand is a measure of the amount of saponifiable matter pr
7、esent.4. Significance and Use4.1 This test method is used to determine the property ofester functionality. Ester functionality determines the utility ofthe wax as well as being a significant quality control test.5. Apparatus5.1 Analytical Balance.5.2 Boiling Chips, chemically resistant glass.5.3 Bur
8、ets, two 50-mL capacity with 0.1-mL graduations.5.4 Erlenmeyer Flasks, 250-mL, alkali-resistant.5.5 Hot Plate.5.6 Reflux Condenser.6. Reagents and Materials6.1 Purity of ReagentsReagent-grade chemicals orequivalent as specified in Practice E 200 shall be used in alltests.6.2 Hydrochloric Acid Standa
9、rd (0.5 N).6.3 Phenolphthalein Indicator Solution (10 g/litre)Dissolve1gofphenolphthalein in 100 mL of USSD3Adenatured ethanol or 95 % ethanol.6.4 Potassium Hydroxide, Alcoholic Solution (6.6 g/litre)Dissolve 6.6 g of potassium hydroxide (KOH) in USSD3Adenatured ethanol or 95 % ethanol. Dilute to 1
10、L with theethanol.6.5 Xylene.7. Procedure7.1 Transfer approximately1gofthesample, weighed tothe nearest 0.001 g to a 250-mL Erlenmeyer flask.7.2 Add 40 mL of xylene and a few boiling chips to theflask. Dissolve by heating on the hot plate to the boiling pointof xylene. As soon as the wax dissolves,
11、remove from the hotplate and add 50.0 mL of 0.1 N ethanolic KOH solution fromthe buret. Fit the flask with a reflux condenser and reflux for 3h using the hot plate.7.3 Remove the condenser from the flask, add 5 drops of thephenolphthalein solution and titrate the sample with 0.5 N HCluntil the pink
12、color disappears. Reheat the sample to theboiling point, and if it turns pink, resume titration until the1This test method is under the jurisdiction ofASTM Committee D21 on Polishesand is the direct responsibility of Subcommittee D21.02 on Raw Materials.Current edition approved Oct. 1, 2007. Publish
13、ed October 2007. Originallyapproved in 1955. Last previous edition approved in 2002 as D 138789(2002).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
14、Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.color once again disappears. Repeat this procedure until thepink color does not reappear on heating. Saponified waxesusually require two repetit
15、ions of heating and additionaltitration until the pink color does not reappear.8. Calculation8.1 Calculate the saponification number as follows:Saponification number 5B 2 A!N 3 56.1C(1)where:A = millilitres of HCl solution required for titration of thesample,B = millilitres of HCl solution required
16、for titration of theblank,C = grams of sample used, andN = normality of the HCl solution.9. Precision and Bias9.1 Precision and bias have been established only forlight-colored waxes melting below 100C.9.1.1 Duplicate results by the same operator shall not beconsidered suspect unless they differ by
17、more than 61.3saponification numbers (95 % confidence limits for average).9.1.2 Results reported by two laboratories shall not beconsidered suspect unless they differ by more than 63.2saponification numbers (95 % confidence limits for average).9.2 Dark-colored waxes or wax melting above 100C, orpoly
18、ethylene copolymer waxes may exhibit poorer reproduc-ibility when running saponification values. See Section 1.9.3 BiasThis test has no bias because the values producedare defined only in terms of this test method.10. Keywords10.1 natural wax; polish; polyethylene wax; saponificationnumber; syntheti
19、c wax; titration; waxASTM 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 infringemen
20、t 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 revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or f
21、or additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views know
22、n 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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 1387 89 (2007)2
