Does anyone know of a dry powder molybdenum disulfide product with longer shelf life than 5 years? Molykote -Z is only warranted in closed packaging for up to 5 years.
MoS2 will decompose by oxidation, also over long storage may absorb water vapor. Both processes can be slowed by choosing good barrier materials for the storage container. Ed is correct that storage in vacuum, or under a nitrogen blanket, may also help prolong shelf life, especially if the vacuum or nitrogen blanket are periodically checked/renewed. It should be possible also to sample and analyse the stored powder to determine if it still meets requirements of the procurement spec., MAS 7866 (MIL-M-7866), but that may be more expensive than buying fresh material, 'twould depend on the quantity stored.