Polarization Phenomena in Collagens from Various Tissues

The various levels of organization of collagens extracted from different tissues (tendon, skin, cartilage) give rise to several polarization phenomena induced by molecular movements of dipolar entities. The corresponding dielectric relaxation time spectrum has been investigated by the Thermally Stimulated Current technique. The contribution of cooperative movements ofpolar and apolar sequences along the main chain has been identified: the corresponding relaxation times are given by Arrhenius equations following a compensation law. The relaxation times obey a Fulcher-Vogel equation and have been assigned to motions delocalized along the whole tropocollagen molecule. Special attention has been paid to dipolar reorientations associated with intra and intermolecular mobility which have been found to be specific of the type of collagen and of its interaction with the other constituents of the organic matrix.