Polymer dynamics in bulk, adsorbed and solution by NMR methods

This dissertation has two sections.; 1. Segmental dynamics of poly(methyl acrylate) in bulk and when adsorbed to anopore by solid state deuterium NMR methods. Anopore is an inorganic membrane, typically used in filtration, but can be used as a substrate for polymer adsorption. Using deuterium NMR, the dynamics of anopore-adsorbed poly(methyl acrylate) (PMA) were examined as a function of temperature. The effect of pore-size on segmental mobility was investigated and determined to have no effect on the adsorption. In low adsorbed amounts, more restricted motions of the polymer chains were found than in the high adsorbed amounts. The higher adsorbed amounts showed segmental mobility that was similar to that of the bulk sample. The PMA-anopore system, however, did not exhibit orientation of the polymer. These results are compared with studies of PMA adsorbed on silica and PMA adsorbed on alumina.; 2. Pulsed field-gradient NMR studies of solvent diffusion in polymer solutions. Self diffusion, the random translational motion of molecules as a consequence of their thermal energy, was examined using pulsed field gradient proton NMR. The self-diffusion of N,N-dimethylformamide in polystyrene was investigated as a function of concentration (0--70% by weight) at temperatures ranging from 25 to 85°C. Also reported is the self-diffusion behavior of solvent mixtures in polymer solutions. Mixtures of toluene and methylene chloride, and acetonitrile and chloroform were used as solvents in the studies of solvent diffusion in poly(methyl methacrylate) (PMMA) solutions. Binary solvent mixtures of different proportions were examined as a function of polymer concentration. The results were analyzed and compared to diffusion theories of Maxwell-Fricke, Mackie Meares and the Vrentas-Duda Free-Volume theory.