Astm D 3643 – 98 pdf free download

Standard Test Method for
Acid Number of Certain Alkali-Soluble Resins1

This standard is issued under the fixed designation D 3643; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of the last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope

1.1 This test method covers the measurement of the free
the acidity present in certain alkali-soluble resins.

1.2 This test method is not suitable for styrene-maleic
anhydride resins.

1.3 The resin manufacturer should specify whether or not
this test method may be used for his product(s).

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 Documents

2.1 ASTM Standards:
D 362 Specification for Industrial Grade Toluene2
D 1152 Specification for Methanol (Methyl Alcohol)3
D 1193 Specification for Reagent Water4

3. Terminology

3.1 Definition:

3.1.1 acid number—the number of milligrams of potassium
hydroxide (KOH) required to neutralize the alkali-reactive
groups in 1 g of material under the conditions of the test.

3.1.1.1 Discussion—If carboxylic anhydrides are present,
only half of these groups will be titrated and indicated by
this test method.

4. Significance and Use

4.1 This test method is used to determine the property of
maleic anhydride resin functionality. Maleic acid anhydride
resin’s functionality determines the utility of resin as well as
is a significant quality control test.