Determination of interatomic distances by solid-state NMR

An overview of physical and chemical properties of polymers has been given. Special attention has been paid to thermodynamic compatibility of polymers in light of its impact on the improvement of mechanical and thermal properties of polymers. The rationale of the choice of compatible poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and polystyrene (PS) blends for present studies is also discussed. General methods of characterization of thermodynamic compatibility of polymers are given. The preference of solid state NMR to other methods as well as its quintessence in structural characterization of solid materials has also been explained. In addition, the major NMR techniques used for structural determination in solid materials are discussed.; Among these techniques, rotor driven spin diffusion techniques were chosen as the most efficient for geometrical investigations in compatible polymer blends. The novelty of the application of this technique to compatible polymer blends has also been demonstrated. Much of the theory of spin diffusion at the rotational resonance condition has been discussed in detail and closely following available literature. Experimental aspects of rotor driven spin diffusion technique have also been discussed in detail. Interatomic distances between a methyl carbon of PPO and protonated aromatic ring carbons of polystyrene have been probed by this technique. Some complications that can arise in the analysis of rotor driven spin diffusion data in polymeric systems have been pointed out. A complete analysis of rotor driven spin diffusion data with extracting of structural parameters has been elaborated.; Computer simulation of NMR experiments has been performed with package software GAMMA (general approach to magnetic resonance mathematical analysis). The importance of simulation of an NMR experiment has been demonstrated. Some basics of programming with GAMMA have also been covered. In addition, the computer modelling of polymer blends has also been performed. Much of the discussion of general aspects of molecular modelling was explicit and includes points skimmed over in other presentations in the literature. Some practical aspects of computer modelling of structures of polymeric systems have been also discussed.; Finally, a novel technique for the determination of interatomic distances in polycrystalline solids and compatible polymer blends has been developed. This novel technique, zero quantum correlation spectroscopy at rotational resonance, has allowed for the explicit evaluation of interatomic distances between selected sites in polycrystalline and polymeric solids. Basic theory of this experiment and detailed experimental realization have been discussed. In addition, the zero quantum coherence time has been measured in polycrystalline and polymeric materials.