SOLID-STATE HIGH RESOLUTION NMR STUDY ON POLY (2, 6-DIMETHYL-1,4-PHENYLENE OXIDE)

摘要

Experiments including 13C spin-lattice relaxation, 13C heteronuclear dipolar dephasing and1H spin diffusion are performed on poly （2, 6-dimethyl-1, 4-phenylene oxide） （PPO）. Theresults show that the rotation of the methyl groups in solid PPO is partially restricted, whichresults in a surprisingly efficient spin diffusion between the aromatic proton and methyl protoncharacterized by a diffusion time of 150μs. The results also show that the aromatic ring insolid PPO is rigid and twisted, which causes all aromatic carbons to be chemicallyunequivalent.