This test method describes the effect of elastomers on copper and is used to detect excessive sulfur due to improper vulcanisation and/or surplus adding of curing agent.
The test uses the fact that black copper sulfide CuS is formed during the reaction of copper with elementary sulfur. The amount of black color provides a fast qualitative hint on the amount of free sulfur.
This test method can provide data for
qualification tests on different elastomers which are in question for a specific application (quality determination),
comparison tests on different delivery batches of a specific elastomer compound (quality assurance).
The time between vulcanization and testing of elastomers shall be at least16 h and not longer than 6 months when investigating to this procedure.