Chemistry Commons^™

Deuteron Nuclear Magnetic Resonance Studies Of Molecular Motion In Solids, Tak Yan Tse

Dissertations, Theses, and Masters Projects

$\sp2$H-NMR is a powerful spectroscopic technique for investigating dynamics in solids. to extend the range of motional rates that can be quantitatively investigated, a new approach for measuring the quadrupolar spin-lattice relaxation time $T\sb{1Q}$ was developed. This uses a Broadband Jeener-Broekaert (BBJB) sequence with echo-detection, which avoids the frequency-discriminated excitation profile and spectral baseline distortion intrinsic to the conventional Jeener-Broekaert (JB) experiment. By combining the BBJB experiment with an Inversion-Recovery sequence with Quadrupole-Echo detection (IRQE), two independent longitudinal relaxation times, $T\sb{1Q}$ and $T\sb{1Z}$, can be measured. Spectral densities of motion $J\sb1(\omega\sb{o}$) and $J\sb2(2\omega\sb{o}$) are extracted from these relaxation times. The …

Physical And Mechanical Behavior Of Amorphous Poly(Arylene Ether-Co-Imidazole)S And Poly(Arylene Ether-Co-Imidazole) Modified Epoxies, Patricia D. Roberts-Mcdaniel

Dissertations, Theses, and Masters Projects

Due to the high crosslink density of cured epoxy resins they generally lack damage tolerance. A significant amount of research has been expended to improve the toughness of epoxies. Research into the area of thermoplastic epoxy modifiers has begun to overcome some of the limitations of early methods of epoxy toughening (i.e. lower modulus and thermal stability).;This study examines the physical and mechanical properties of random poly(arylene ether-co-imidazole) (PAE-co-Is) and the characterization of epoxies modified with poly(arylene ether-co-imidazole)s.;Poly(arylene ether-co-imidazole)s exhibited the highest solubility in N,N,N{dollar}\rm\sp\prime,N\sp\prime,{dollar}-tetraglycidyl- 4,4{dollar}\sp\prime{dollar} diaminodiphenyl methane (TGMDA) based resins. The high molecular weight polymers caused significant decreases in …

Characterization And Modeling Of Amino Epoxide Resins, Maria Anastasia Argiriadi

Dissertations, Theses, and Masters Projects

No abstract provided.

Macroporous Polymer Synthesis And Characterization: The Role Of Molecular Recognition In The Regioselectivity Of Sucrose Reactions, Gilbert Joshua Matare

Masters Theses

Molecular recognition has recently emerged as a unique technique for making synthetic polymers with selective binding cavities which can stereoselectively and regioselectively bind to a template molecule in a fashion similar to natural enzymes and antibodies. Its industrial applications in chemistry and biomedicine have been recently exploited. Typical examples include the resolution of amino acids, enantio-separation of racemates and bioactive molecules, selective binding of metal ions and in HPLC investigations. Our research is focused on applying molecular recognition studies to improve the regioselectivity of sucrose reactions.

Sucrose is an abundant industrial raw material of immense industrial importance however, its full …