The Application Of Nmr In Polymor Structure

With the developing of nuclear magnetic resonance (NMR) techniques, it becomes more important in chemistry,physics,biology,medicine and materials science research.In this paper, using nuclear magnetic resonance techniques, interaction between the cationic surfactant CTAB and water-soluble polymer polyvinyl alcohol (PVA) was studied. The factor of synthesis between PVA and methyl methacrylate (MMA) was discussed, and the polymer structure was analyzed. For the first time, t the structure of corn silk was attached.First, using ¹H NMR, spin - lattice relaxation time (T₁) and spin - spin relaxation time (T₂) techniques, in mixed solvent, the molecular motion of polyvinyl alcohol (PVA)was studied. The reason of the water peaks gradually wider and chemical shift changing and the movement of molecular chain of PVA change was analysised; Combination gCOSY and enhance the spectrum of two-dimensional nuclear Overhause (2D NOESY) techniques, interaction between the cationic surfactant CTAB and PVA was studied: the translational mobility of PVA suffocated with the presence of surfactant CTAB; The translational mobility of CTAB decrease with the increase in PVA concentration.Second, PVA and methyl methacrylate (MMA) polymerization was studied by SEM, FTIR, 1H NMR, XRD, solid ¹³C NMR techniques. The influence of ultrasound and H₂O₂, reaction time and reaction temperature on the polymerization were discussed. And by solid ¹³C NMR calculating the conversion rate of PVA in different reaction time.Third, using SEM, FTIR, XRD, solid ¹³C NMR, corn silk dealing with the water and ethanol was studied. Combined with computer points peak fitting technique, the structure of corn silk was attached. These results suggested that after extraction through water and ethanol, the corn be off some materials that extremely soluble in water and ethanol, but the main functional group is not affected.