Drifting of Fluorocarbon-Elastomer Vulcanizates as a Function of Water Interaction

Abstract

Postcured fluorocarbon-elastomer (FKM) vulcanizates show con siderable changes in their physical properties during storage. The degree of these changes is dependent upon the water content in the rubber matrix and is significantly influenced by the fillers being used; it is, however, unaffected by the vulcanizing system. The changes can be reversed by a repeated postcure, because the adsorbed water, again, evaporates quantitatively. Gravimetrical measurements demonstrate the functional dependence of the observed changes on the interaction between filler and water, which secondarily affects the in teraction between filler and polymer and finally leads to a change in the net work structure.