NUCLEAR-MAGNETIC-RESONANCE STUDIES OF BLENDS CONTAINING POLY(ETHYLENE-TEREPHTHALATE) (PET) AND POLY(P-HYDROXYBENZOIC ACID-CO-P-HYDROXYNAPHTHOIC ACID) (VECTRA-A)

Solid-state NMR techniques are used to characterize the interfacial interactions and morphology in Vectra-A/PET blends. Two-dimensional rotor-driven C-13 Spin diffusion NMR and indirect detection of H-1 spin-lattice relaxation (T1) are used to determine the extent of intimate molecular mixing, carbon-13 magic angle spinning line shapes emanating from methylene carbons in PET are used to monitor the conformation of PET in the blends, and indirect detection of H-1 spin-lattice relaxation in the rotational frame (T1rho) is used to estimate the polymer crystallinity. The results are presented in terms of a scenario in which Vectra can penetrate PET regions in blends upon annealing in the melt. This scenario accounts well for previously published thermal data.