Dynamic molecular mobility of polyurethane by a broad range dielectric and mechanical analysis

David Dupenne (1, 2) , Aurélien Roggero (1) , Eric Dantras (1) , Antoine Lonjon (1) , Thierry Pierré (2) , Colette Lacabanne (1)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 IRT Saint Exupéry - Institut de Recherche Technologique

The dynamic molecular mobility of poly(2-hydroxypropyl methacrylate) (PHPMA) base polyurethane (PU) was studied over a broad range of frequency and temperature by combining dynamic dielectric spectroscopy and dynamic mechanical analysis. Two hydrated levels were considered in this study: dry and room humidity states. In dry state, two secondary relaxations γ and β are identified. And in room humidity state, a βsw mode is pointed out. These modes are well known in poly(hydroxylalkyl methacrylate)s. The main α relaxation is influenced by humidity and crosslinks. The Kramers-Kronig transform is used to reveal an ionic conductivity σionic. Relaxation times extracted from dielectric and mechanical analyses are coherent for PU and PHPMA. This correlation allows us to propose an interpretation of relaxations at a molecular level.

Mots clés: Polyurethane; Dynamic dielectric spectroscopy; Dynamic mechanical analysis; Thermal properties; PHPMA; Coating

Domaines: Matériaux; Matériaux

David Dupenne, Aurélien Roggero, Eric Dantras, Antoine Lonjon, Thierry Pierré, et al.. Dynamic molecular mobility of polyurethane by a broad range dielectric and mechanical analysis. Journal of Non-Crystalline Solids, 2017, vol. 468, pp. 46-51. ⟨10.1016/j.jnoncrysol.2017.04.022⟩. ⟨hal-01537201⟩