Macromolecules, Vol.27, No.8, 2211-2218, 1994
2-Dimensional NMR Characterization of Short-Range Order in a Miscible Blend of Polystyrene and Poly(2,6-Dimethyl-P-Phenylene Oxide)
Measurements of H-1 NMR spin diffusion have been obtained for a miscible polymer blend of deuterated polystyrene (PS-d5) and poly(2,6-dimethyl-p-phenylene oxide) (PPO) through the use of a new solid-state heteronuclear correlation (HETCOR) two-dimensional (2D) method. Proton spin-diffusion data were used to examine local ordering of PS-d5 and PPO segments and to experimentally measure the number of heterosegmental contacts. The data were compared with theoretical results obtained from a lattice simulation based on Monte Carlo methods. Solid-state 2D HETCOR spectra were obtained through the use of multiple-pulse selective cross-polarization (WIM-24) and with BB-12 C-13 decoupling during the evolution period. An additional mixing period was inserted for H-1 spin diffusion. This approach provided greater resolution than the previous homonuclear H-1-H-1 method while retaining the former method’s selectivity for closely spaced protons. Consequently, a greater variety of polymer mixtures is now accessible for study.
Keywords:SOLID-STATE NMR;NUCLEAR MAGNETIC-RESONANCE;PROTON SPIN DIFFUSION;POLYMER BLENDS;POLY(2;6-DIMETHYL-1;4-PHENYLENE OXIDE);MECHANICAL-PROPERTIES;MONTE-CARLO;SPECTROSCOPY;MIXTURES;BEHAVIOR