Evaluation of EVA-PVAc blend behavior by 1-D and 2-D solid-state NMR

Ethylene-co-vinyl acetate and poly(vinyl acetate) blends were prepared in d ifferent proportions by melting in a HAAKE Rheomix mixer. The blends were p repared at a fixed temperature, rotation rate, and processing time. High-re solution solid-state nuclear magnetic resonance was chosen to characterize the blends with respect to structure-mobility-compatibility employing magic angle spinning with cross polarization and high-power hydrogen decoupling and the measurements of the proton spin-lattice relaxation time in the rota ting frame (T(1)(H)rho). The miscibility between polymer chains was also st udied by two-dimensional H-1-C-13 Shift correlation (HETCOR). (C) 1999 John Wiley & Sons, Inc.