ASTM D4924-21 - Standard Classification for Petroleum Waxes for Use in Rubber Compounding

1.1 This classification is intended to establish a classification system and test methods for petroleum waxes used in rubber compounding primarily as a static protective agent or material for unsaturated rubbers such as styrene-butadiene rubber, polyisoprene rubber, natural rubber, chloroprene rubber, acrylonitrile-butadiene rubber, and polybutadiene rubber. These unsaturated rubbers are subject to ozone cracking. Under certain exposure conditions, waxes retard this cracking.

1.2 This classification is applicable to petroleum waxes used as process aids in rubber compounding. It is not applicable to nonpetroleum waxes such as carnuba wax, candelille wax, or ceresin wax, nor to synthetic hydrocarbon waxes such as polyethylene wax. These non-petroleum waxes display a different behavior on gas chromatographic analysis than do petroleum waxes.

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.