ASTM D3168-85(2022)

5.1?Identification of specific acrylic polymers in emulsion paints is often difficult or impossible by infrared alone. This is particularly true when the acrylic is present in a small amount as a comonomer with vinyl acetate, or when blended with alkyds or other ester systems. If identification of an acrylic component is required in such a system, it may often be accomplished by gas-liquid chromatographic analysis of the pyrolyzed paint film. The presence of a number of other polymers may often also be confirmed by pyrolysis since they produce characteristic and reproducible pyrograms.

5.2?The pyrograms obtained from unknown samples vary in complexity according to the sample composition. It is necessary to establish the presence or absence of as many components as possible from a study of the infrared spectra obtained in the first part of this practice. The gas-liquid chromatography results may then be used to help identify any unknown components present and to confirm identifications made by infrared.

1.1?This practice describes a procedure for the qualitative identification in emulsion paints of most types of polymers present as major components of the paint vehicle. Limitations are discussed in Sections 5 and 10.

1.2?The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3?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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.