ASTM D8411-21

4.1MBT is commonly used in rubber compounding as a curing accelerator for rubber and latex products. The determination of MBT in cured rubber is important to assess the risk of a release of this hazardous substance when rubber is in prolonged contact with human skin or mucous membranes.

4.2Neo-formed MBT from MBTS might be created during the process of vulcanization when benzothiazolesulfenamides are used in the compound as accelerators, and therefore, it is part of the total MBT content in the cured rubber.

4.3The purity of MBT as raw material can be evaluated by following Test Method D1991 based on a potentiometric titration of MBT with sodium hydroxide.

4.4MBT is also a major impurity in MBTS. While MBTS is sparingly soluble in any organic solvent, MBT is very soluble. The amount of MBT contained in MBTS as raw material can be determined according to Test Method D5044.

4.5This test method may be used as a quality control tool as well as for research and development work.

1.1This standard test method covers a procedure for the determination of extractable 2-Mercaptobenzothiazole (MBT) in rubber by high performance liquid chromatography (HPLC) to assess its bioavailability.

1.2The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3This 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.

1.4This 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.