Polymer Structure And Molecular Dynamics Studied By Solid State Nmr

In polymer science and technology, the advanced development of various new polymer materials with excellent properties and functions is desirable. For this purpose it is necesary to determine the exact relationship between physical properties and molecular structure-dynamics with powerful techniques. One such technique is solid state NMR. Recently, high resolution NMR studies of solids have been realized by using advanced pulse and mechanical techniques, which has resulted in a variety of structural and dynamical information on polymer systems. Solid state NMR has provided characteristic information which cannot be obtained by other spectroscopic methods. This book is divided into two parts. The first part covers the principles of NMR, important NMR parameters such as chemical shifts, relaxation times, dipolar interactions, quadrupolar interactions, pulse techniques and new NMR methods. In the second part, applications of NMR to a variety of polymer systems in the solid state are described. Features of this book: • Contains an up-to-date and comprehensive account of solid state NMR of polymers by leading researchers in the field • Provides a compilation of solid state NMR of polymers, which makes it an ideal reference book for both NMR researchers and general polymer scientists. This book will be of interest to the NMR community, and will be invaluable for both the beginner and the expert.

"Research on the dynamic properties and related molecular reorientation processes in polymer chains has attracted special attention in recent years. The solid-state nuclear magnetic resonance (SSNMR) is one of the most important complementary techniques in the scientific testing of macromolecules. When polymer molecules make reorientation motions, a fluctuating local magnetic field is generated. Thus, the shape of the resonance line emerges as a function of temperature and reveals the activation energy of the polymer chain"--

NMR has made important contributions to our understanding of structure–property relationships in polymers. This book provides an up-to-date and comprehensive overview of the fundamentals of NMR, with applications of multidimensional NMR and the new solution and solid-state methods in polymer science. NMR of Polymers is written by leading authorities for graduate students and professionals in academia and industry. Provides comprehensive overview of NMR in Polymer Science Covers multidimensional NMR Includes new solution and solid state methods Addresses chain conformation and dynamics

NMR spectroscopy has emerged as one of the most important methods for the solid-state characterisation of polymers. This report gives an overview of the methods and applications of NMR to relevant polymer problems with an emphasis on how NMR can be used for materials characterisation and to understand structure-property relationships in polymers. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.

Since the introduction of FT-NMR spectroscopy around five decades ago, NMR has achieved significant advances in hardware and methodologies, accompanied with the enhancement of spectral resolution and signal sensitivity. Rapid developments in the polymers field mean that accurate and quantitative characterization of polymer structures and dynamics is the keystone for precisely regulating and controlling the physical and chemical properties of the polymer. This book specifically focuses on NMR investigation of complex polymers for the polymer community as well as NMR spectroscopists, and will push the development of both fields. It covers the latest advances, for example high field DNP and ultrafast MAS methodologies, and show how these novel NMR methods characterize various synthetic and natural polymers.

Solid-State NMR is a branch of Nuclear Magnetic Resonance which is presently experiencing a phase of strongly increasing popularity. The most striking evidence is the large number of contributions from Solid-State Resonance atNMR meetings, approaching that ofliquid state resonance. Important progress can be observed in three areas: Methodological developments, applications to inorganic matter, and applications to organic matter. These developments are intented to be captured in three volumes in this series, each of them being devoted to more or less one of these areas. The present volume on Solid-State NMR III is devoted mainly to organic matter. The recent developments of deuteron NMR and their applications are reviewed in the first chapter. Crosspolarization, MAS, and dynamic angle spinning are being explored for enhancement of information and sensitivity. In addition to the analysis of classical relaxation times and modern 2D spectra, detailed dynamic information becomes accessible from investigations of the relaxation time anisotropies. The second chapter examines cross-polarization in static and rotating solids under conditions of spin diffusion and thermal motion. The underlying dipole-dipole interaction is further exploited by the techniques described in the third chapter for studies of polymer-polymer miscibility. Short range techniques are discriminated from long-range techniques based on spin diffusion. The use ofthese techniques is illustrated by a case study ofPMMAJPVF blends. The last chapter addresses novel z methods and applications of two-dimensional exchange NMR for investigations of relative molecular orientations, polymer morphology, molecular dynamics, and macroscopic molecular order.

NMR spectroscopy is the most valuable and versatile analytical tool in chemistry. While excellent monographs exist on high-resolution NMR in liquids and solids, this is the first book to address multidimensional solid-state NMR. Multidimensional techniques enable researchers to obtain detailed information about the structure, dynamics, orientation, and phase separation of solids, which provides the basis of a better understanding of materials properties on the molecular level.Dramatic progress-much of it pioneered by the authors-has been achieved in this area, especially in synthetic polymers. Solid-state NMR now favorably competes with well-established techniques, such as light, x-ray, or neutron scattering, electron microscopy, and dielectric and mechanical relaxation.The application of multidimensional solid-state NMR inevitably involves use of concepts from different fields of science. This book also provides the first comprehensive treatment of both the new experimental techniques and the theoretical concepts needed in more complex data analysis. The text addresses spectroscopists and polymer scientists by treating the subject on different levels; descriptive, technical, and mathematical approaches are used when appropriate. It presents an overview of new developments with numerous experimental examples and illustrations, which will appeal to readers interested in both the information content as well as the potential of solid-state NMR. The book also contains many previously unpublished details that will be appreciated by those who want to perform the experiments. The techniques described are applicable not only to the study of synthetic polymers but to numerous problems in solid-state physics, chemistry, materials science, and biophysics. Presents original theories and new perspectives on scattering techniques Provides a systematic treatment of the whole subject Gives readers access to previously unpublished material Includes extensive illustrations

‘‘Biopolymers’’ are polymeric materials of biological origin, including globular, membrane, and fibrous proteins, polypeptides, nucleic acids, po- saccharides, lipids, etc. and their assembly, although preference to respe- ive subjects may be different among readers who are more interested in their biological significance or industrial and/or medical applications. Nevert- less, characterizing or revealing their secondary structure and dynamics may be an equally very important and useful issue for both kinds of readers. Special interest in revealing the 3D structure of globular proteins, nucleic acids, and peptides was aroused in relation to the currently active Structural Biology. X-ray crystallography and multidimensional solution NMR sp- troscopy have proved to be the standard and indispensable means for this purpose. There remain, however, several limitations to this end, if one intends to expand its scope further. This is because these approaches are not always straightforward to characterize fibrous or membrane proteins owing to extreme difficulty in crystallization in the former, and insufficient spectral resolution due to sparing solubility or increased effective molecular mass in the presence of surrounding lipid bilayers in the latter.

In this dissertation, we have focused on the study of the interplay of structure and molecular dynamics of soft materials including supramolecules and semicrystalline polymers at the molecular scale through various state-of-the-art solid state NMR techniques. The dissertation is consisting of three parts. In Chapter IV, we focus on the atomic scale dynamics for a Janus bisamide supramolecule. Relationship between unique structure and dynamics will be demonstrated. On the basis of the determined conformations and packing structures of the alkyl chains in ordered and disordered crystalline phases, along with the geometry and kinetic parameters of the structural elements' dynamics, the self-assembly, the phase-transition mechanisms, and the relationship between the structure and dynamics of the asymmetric Janus bisamide supramolecules were addressed.In Chapter V, we investigate molecular dynamics of semicrystalline polymers including poly-lactic acid-PLA, polyethylene oxide PEO, and polyoxymethylene POM in well controlled morphologies. Based on dynamic frequency and geometry of molecular motions, we've discussed possible structural factors that influence chain dynamics in the crystalline regions. In Chapter VI, we investigate the chain-trajectory of PLA stereocomplex by 13C Double-Quantum -DQ NMR in combination with spin-dynamics simulation. Poly-L-lactide PLLA and poly-D-lactide -PDLA alternatively pack with each other and form stereocomplex crystals (SCs). The habits of SCs formed in the dilute solution depend highly on the molecular weight Mw. It was demonstrated that the ensemble average of the successive adjacent re-entry number n for the l-PLLA chains drastically changes depending on Mws of the counter PDLA chains in the SCs. It was concluded that the limited space for two kinds of PLA chains at the fold surface significantly influence the chain-folding patterns inside the SCs and as a result led to the unique Mw dependence of the crystal morphology.