Study On Nuclear Magnetic Resonance Relaxation Of Polymer

This thesis mainly makes use of the nuclear magnetic resonance(NMR) technique and discussed the relaxation time as well as the molecular motion of some polymer in solution . Including research of PVP molecules claw size and movement behavior, come to a dicision about the influence on macromolecules movement behavior by molecular interaction force. In addition,this paper still study up on the molecular interaction of two polymer blends, characterized by X-ray diffraction, scanning electron microscope, infrared etc.Firstly, An assignment of the main 1H and ¹³C—NMR resonances of PA66 in solution has been carried out by using 1D and 2D NMR technique. The process of relaxation was fitted with a biexponential function . Finding that the solution system of PA66 is different from general polymer, With the increase of concentration,PA66 solution gradually becomes soft-solid-like.Secondly, The spin-spin relaxation time of PVP in H₂O/acetone was measured, and the process of relaxation was fitted with a single exponential function. The visco sity of PVP in mixed solvents confirmed previous conclusion about claw size in mixed solvents of PVP and show the changing laws of macromolecules movement.Again, Chemical shift of each proton in CMC/PAM system was measured by liquid NMR method . CMC/PAM blends was prepared via melt mixing method and the interaction between macromolecules of the blends was characterized by IR.Finally, This paper prepared PA66/PVP blends by solution cast method, analysised compatibilities of PA66 and PVP by IR,SEM,XRD and discussed the interaction between macromolecules and thermal properties.