Active Standard ASTM D7389 | Developed by Subcommittee: D21.02
Book of Standards Volume: 15.04
Historical (view previous versions of standard)
Significance and Use
4.1 This test method is used to determine the free acid content of MAH-grafted waxes. The potential hydrolysis of the anhydride functionality of this wax in storage makes them unsuitable for determining free acid content by Test Method D1386. Free acid content is a significant quality control test, and is a determinant of the utility of the wax.
1.1 This test method covers the determination of the acid number of maleic anhydride (MAH) grafted waxes. The number is obtained by direct titration of the material and indicates the amount of free acid present.
1.2 This test method is applicable to MAH-grafted waxes because it uses a special sample preparation step (7.1) that is not required for other waxes. The special sample preparation reverses the hydrolysis of acid anhydride that can occur during storage of the wax.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D1386 Test Method for Acid Number (Empirical) of Synthetic and Natural Waxes
E200 Practice for Preparation, Standardization, and Storage of Standard and Reagent Solutions for Chemical Analysis
ICS Number Code 75.140 (Waxes, bituminous materials and other petroleum products)