Dynamics of glass-forming di-n-butyl phthalate as studied by NMR

Spin-lattice relaxation times T-1 and nuclear Overhauser effect (NOE) enhancement factors for the individual ring carbons in di-n-butyl phthalate (DBF) show that the reorientational correlation function corresponding to the global dynamics in supercooled liquid can be described by a Davidson-Cole distribution. Measurements of proton spin-lattice relaxation times T-1 and T-1p, as well as H-1 NMR spectra at temperatures below the glass transition temperature, T-g, reveal that the same distribution holds also for description of local dynamics in glassy DBF. The activation parameters of the motions detected are derived. (C) 1997 Elsevier Science B.V.