ASTM D1386-10

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D1386–98(Reapproved 2004) Designation:D1386–10
Standard Test Method for
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Acid Number (Empirical) of Synthetic and Natural Waxes
This standard is issued under the fixed designation D1386; 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 epsilon (´) 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. Scope
1.1 This test method covers the determination of the acid number of synthetic waxes and natural waxes.The number is obtained
by direct titration of the material and indicates the amount of free acid present.
1.2 This test method, using an ethanol-xylene mixture, is applicable to all natural waxes, including carnauba. The test method
is also applicable to oxidized microcrystalline waxes, oxidized Fischer-Tropsch, oxidized polyethylene, and montan esters.
1.3
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Document
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2.1 ASTM Standards:
E200 Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
3. Terminology
3.1 Definition:
3.1.1 acid number or acid value—the number of milligrams of potassium hydroxide necessary to neutralize1gofthe sample.
4. Significance and Use
4.1 This test method is used to determine the property of acid functionality.Acid functionality determines the utility of the wax
as well as being a significant Quality Control test.
5. Apparatus
5.1 Analytical Balance.
5.2 Buret, 50-mL, with 0.1-mL graduations.
5.3 Flasks, acid value, 250-mL.
6. Reagents and Materials
6.1 Purity of Reagents—Reagent-grade chemicals or equivalent, as specified in Practice E200, shall be used in all tests.
6.2 Ethanolic Potassium Hydroxide, Standard Solution (0.1 N)—Dissolve 6.6 g of potassium hydroxide in 5.6 g of distilled
water. Dilute with USSD3A denatured ethanol or 95 % ethanol to 1000 mL. Standardize with 0.1 N hydrochloric acid.
6.3 Phenolphthalein Indicator Solution (10 g/litre)—Dissolve1gof phenolphthalein in 100 mLof USSD3A, denatured ethanol
or 95 % ethanol.
6.4 Xylene.
7. Procedure
7.1 Transfer 1 to2gofthe sample, weighed to the nearest 0.001 g, to a 250-mL acid-value flask. Add 40 mL of xylene. Heat
on a hot plate or water bath to put the sample into solution. Occasional swirling may be necessary.
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This test method is under the jurisdiction of ASTM Committee D21 on Polishes and is the direct responsibility of Subcommittee D21.02 on Raw Materials.
Current edition approved Sept.May 1, 2004.2010
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