Alain Pouchelon

The swelling behaviour of siloxane elastomers in relation to their microscopic structure

Swelling experiments have been performed in order to characterize elastomer networks. The value of the interaction parameter X of the Flory-Rehner equation has been evaluated. We were particularly interested in equilibrium swelling and the kinetics of swelling when the solvent was of the same nature as the network polymer; a siloxane fluid in a siloxane elastomer. Now, the swelling capacity of elastomers can easily be predicted and this is of particular importance in relation to their formulation. The swelling experiments also revealed a more complex kinetics than expected. We relate this kinetics to the self-bleeding process and give an interpretation based on the network microstructure. Finally, some data from electron microscopy in relation to light and neutron scattering and also results of a thermoporometry study of the elastomers are discussed.