Abstract
In this work we present a proton spin-lattice relaxation study of the molecular dynamics in an urethane/urea anisotropic elastomer film and in the two precursor pre-polymers, using conventional and fast field cycling NMR techniques. The precursor pre-polymers used were polypropylene oxide with three isocyanate terminal groups (PU) and polybutadiene diol (PBDO). The proton spin-lattice relaxation time T 1 dispersions were obtained at several different temperatures in the frequency range of 4 kHz to 100 MHz. The results show that while the molecular dynamics in the two precursor pre-polymers is well explained by the Rouse model, the solid elastomer film exhibits a relaxation dispersion where regions I, II and III of molten chain dynamics are clearly seen. The solid anisotropic elastomer film shows a molecular dynamical behaviour similar to other isotropic networks.
Original language | English |
---|---|
Pages (from-to) | 119/[319]-126/[326] |
Journal | Molecular Crystals and Liquid Crystals |
Volume | 450 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jul 2006 |
Keywords
- Anisotropic elastomers
- Molecular dynamics
- NMR