SPATIALLY-RESOLVED NMR SPIN-DIFFUSION IN SOLID POLYMERS

Measurements of the spatial distribution of microscopic domain sizes a re reported using spatially resolved H-1 NMR spin diffusion in solid p olymers. Microscopic space encoding for spin diffusion is achieved for two classes of polymers with dynamic heterogeneities by use of the di polar filter. Macroscopic space is resolved by phase-encoded magic-ech o imaging using H-1 NMR. Spatial changes of the average domain sizes a re detected for diblock polymer poly(styrene-b-isoprene) and poly(ethy lene oxide) phantoms. As a first application of this new method, chang es in microscopic domain sizes due to high-voltage electrical discharg e are imaged in low-density polyethylene cable-insulator material. (C) 1996 Academic Press, Inc.