[工学]高分子材料研究方法-核磁共振与电子顺 磁共振波谱法.ppt

3.5.1 Applications of NMR on Polymers Molecular Movement: spin-spin relaxation time Solid NMR 3.5.2 Applications of EPR on Polymers Free Radicals in Initiating Systems ROOH-para-N,N-dimethylbenzylamine system MNP heptacoset 3.5.2 Applications of EPR on Polymers Free Radicals in Initiating Systems Ammonium persulfate (APS)-cycloamine system MNP heptacoset 3.5.2 Applications of EPR on Polymers Dynamics of Polymerization Decomposition of initiators Chain initiation Chain termination Chain propagation 3.5.2 Applications of EPR on Polymers Chain Structure Head-head structure in PVC MNP nonet 3.5.2 Applications of EPR on Polymers Chain Structure Head-tail structure in PVC MNP hexet 3.2.4 Elucidation of 1H NMR Spectra Methods Further Elucidating 1H NMR Spectra High field 1H NMR spectra Shift reagents: Decoupled spectra The nuclear overhauster Effect The exchanging of the deterium 3.3 13C NMR Spectroscopy Comparison with 1H NMR Spectroscopy Proton-decoupling Methods 3.3.1 Comparison with 1H NMR Spectra Sensitivity Low magnetogyric ratio Low natural abundance of 13C: Resolution δ: 0-300, larger than that of 1H NMR by 20 folds Some empirical rules: 3.3.1 Comparison with 1H NMR Spectra Objects: The molecular skeleton Functional groups: C=O, C≡N, quaternary carbon Spin-Spin Coupling 13C-1H coupling 3.3.2 Proton-decoupling Methods Broad-band Decoupling: Off-resonance Decoupling Spin Tickling 3.4 EPR Spectroscopy Principles of EPR Spectroscopy Instrumentation Elucidation of EPR Spectra Comparison between EPR Spectroscopy and NMR Spectroscopy 3.4.1 Principles of EPR Spectroscopy Para-magnetism and Anti-magnetism Para-magnetism matters with unpaired (parallelly spinned) electrons, μs ≠ 0 Anti-magnetism matters with paired (anti-parallelly spinned) electrons, μs = 0 3.4.1 Principles of EPR Spectroscopy Para-magnetism and Anti-magnetism Para-magnetic matters Matters with free radicals Molecules with double or multiple unpaired electrons Mole