A Practical Guide to Understanding the NMR of Polymers

ISBN-13: 9780471371236 / Angielski / Twarda / 2004 / 418 str.

P. Mirau

Opis

A Practical Guide to Understanding the NMR of Polymers presents an introduction to the theory and practice of NMR, and includes sections on the fundamental principles of NMR and the applications to polymers. This book will help readers understand how these methods can be used to determine the chemical structure of polymers that influences the macroscopic properties. Solid state NMR methods are introduced to enable the readers to measure the structure of polymers on longer length scales. It is also shown how NMR is used to measure the molecular dynamics that can be related to the mechanical properties of polymers.

Recenzje

" useful for researchers or upper level undergraduate and graduate students exploring NMR for characterizing polymers." ( E–STREAMS, April 2006)

this book presents an introduction to the theory and practice of NMR (Apollit, 13^th December 2005)

"Students and researchers in polymer and analytical chemistry will find this book a useful resource." (Analytical Chemistry, February 1, 2005)

Spis treści

1. Introduction to NMR.

1.1 Introduction.

1.2 Basic Principles of NMR.

1.2.1 Introduction.

1.2.2 Magnetic Resonance.

1.2.3 The Rotation Reference Frame.

1.2.4 The Bloch Equations.

1.2.5 Pulsed NMR.

1.2.6 The Fourier Transform.

1.2.7 The Product Operator Formalism.

1.3 Chemical Shifts and Polymer Structure.

1.3.1 Molecular Structure and Chemical Shifts.

1.3.1.1 Chemical Structure Effects.

1.3.1.2 Inductive Effects.

1.3.1.3 Anisotropic Shielding.

1.3.1.4 Chemical Exchange.

1.3.2 Proton Chemical Shifts.

1.3.3 Carbon Chemical Shifts.

1.3.4 Other Nuclei.

1.3.4.1 Fluorine.

1.3.4.2 Silicon.

1.3.4.3 Phosphorus.

1.3.4.4 Nitrogen.

1.4 Spin–Spin Coupling.

1.4.1 Introductions.

1.4.2 Nomenclature for Spin–Spin Coupling.

1.4.3 Spin–Spin Coupling Patterns.

1.4.3.1 Strong Coupling.

1.4.3.2 Scalar Coupling and nD NMR.

1.4.4 Proton–Proton Coupling.

1.4.5 Proton–Carbon Coupling.

1.4.6 Other Nuclei.

1.4.6.1 Fluorine Couplings.

1.4.6.2 Phosphorous Couplings.

1.4.6.3 Silicon Couplings.

1.4.6.4 Nitrogen Couplings.

1.4.7 Homonuclear Couplings in Insensitive Nuclei.

1.5 NMR Relaxation.

1.5.1 Introduction.

1.5.2 Relaxation Mechanisms.

1.5.2.1 Dipole–Dipole Interactions.

1.5.2.2 Quadrupolar Interactions.

1.5.2.3 Chemical Shift Anisotropy.

1.5.2.4 Paramagnetic Relaxation.

1.5.2.5 Other relaxation Mechanisms.

1.5.3 Spin–Lattice Relaxation.

1.5.3.1 Heteronuclear Spin–Lattice Relaxation.

1.5.3.2 Homonuclear Spin–Lattice Relaxation.

1.5.4 Spin–Spin Relaxation.

1.5.5 The Nuclear Overhauser Effect.

1.5.5.1 Heteronuclear Nuclear Overhauser Effects.

1.5.5.2 Homonuclear Nuclear Overhauser Effects.

1.6 Solid State NMR.

1.6.1 Chemical Shift Anisotropy.

1.6.2 Magic–Angle Sample Spinning.

1.6.3 Dipolar Broadening and Decoupling.

1.6.4 Cross Polarization.

1.6.5 Quadrupolar NMR.

1.7 Multidimensional NMR.

1.7.1 Magnetization Transfer in nD NMR.

1.7.1.1 Through–Bond Magnetization Transfer.

1.7.1.2 Through–Space Magnetization Transfer.

1.7.2 Solution 2D NMR Experiments.

1.7.2.1 COSY.

1.7.2.2 TOCSY.

1.7.2.3 Heteronuclear Multiple Quantum Coherences.

1.7.2.4 2D Exchange NMR.

1.7.2.5 J–Resolved NMR.

1.7.3 Solid–State 2D NMR Experiments.

1.7.3.1 2D Exchange NMR.

1.7.3.2 Wideline Separation Spectroscopy.

1.7.3.3 Heteronuclear Correlation.

2. Experimental Methods.

2.1 Introduction.

2.2 The NMR Spectrometer.

2.2.1 The Magnet.

2.2.2 Shim Coils.

2.2.3 RF Console.

2.2.4 NMR Probes.

2.2.5 Computer.

2.3 Tuning the NMR Spectrometer.

2.3.1 Adjusting the Homogeneity.

2.3.2 Adjusting the Gain.

2.3.3 Tuning the Probe.

2.3.4 Adjusting the Pulse Widths.

2.4 Solution NMR Methods.

2.4.1 Sample Preparation.

2.4.2 Data Acquisition.

2.4.3 Decoupling.

2.4.4 Data Processing.

2.4.4.1 Baseline Corrections.

2.4.4.2 Digital Resolution and Zero–Filling.

2.4.4.3 Window Functions.

2.4.4.4 Phasing.

2.4.4.5 Quadrature Detection.

2.4.4.6 Referencing.

2.4.5 Quantitative NMR.

2.4.6 Sensitivity Enhancement.

2.4.7 Spectra Editing.

2.5 Solid–State NMR Methods.

2.5.1 Magic–Angle Sample Spinning.

2.5.2 Gross Polarization.

2.5.3 Decoupling.

2.5.4 Wideline NMR.

2.5.5 Solid–State Proton NMR.

2.6 NMR Relaxation.

2.6.1 NMR Relaxation in Solution.

2.6.1.1 Spin–Lattice Relaxation.

2.6.1.2 Spin–Spin Relaxation.

2.6.1.3 Nuclear Overhauser Enhancements.

2.6.2 Solid–State NMR Relaxation.

2.6.2.1 Spin–Lattice Relaxation.

2.6.2.2 Rotating–Frame Spin–Lattice Relaxation.

2.7 Multidimensional NMR.

2.7.1 Data Acquisition.

2.7.1.1 Digital Resolution and Acquisition Times in nD NMR.

2.7.1.2 Inverse Detection.

2.7.1.3 Phase Cycling.

2.7.1.4 Quadrature Detection.

2.7.1.5 Pulsed Field Gradients.

2.7.1.6 Decoupling.

2.7.2 Data Processing.

2.7.2.1 Apodization.

2.7.2.2 Phasing.

2.7.2.3 Baseline and t₁ Noise.

2.7.2.4 Linear Prediction and Zero–Filling.

3. The Solution Characterization of Polymers.

3.1 Introduction.

3.1.1 Polymer Microstructure.

3.1.1.1 Regioisomerism.

3.1.1.2 Stereochemical Isomerism.

3.1.1.3 Geometric Isomerism.

3.1.1.4 Branching and Endgroups.

3.1.1.5 Chain Architecture.

3.1.1.6 Copolymers.

3.1.2 Spectral Assignments in Polymers.

3.1.2.1 Model Compounds and Polymers.

3.1.2.2 Polymer Chain Statistics.

3.1.2.3 Chemical Shift Calculations.

3.1.2.4 The –Gauche Effect.

3.1.2.5 Spectral Editing.

3.1.2.6 Multidimensional NMR.

3.2 Stereochemical Characterization of Polymers.

3.2.1 The Observation of Stereochemical Isomerism.

3.2.2 Resonance Assignments for Stereosequences.

3.2.2.1 Assignments of Stereosequences Using Model Compounds.

3.2.2.2 Assignments of Stereosequences Using Polymerization Statistics.

3.2.2.3 Assignments of Stereosequences Using Chemical Shift and Conformational Calculations.

3.2.2.4 Assignments of Stereosequences Using nD NMR.

3.3 Regioisomerism in Polymers.

3.4 Defects in Polymers.

3.4.1 Branching.

3.4.2 Endgroups.

3.5 Polymer Chain Architecture.

3.6 Copolymer Characterization.

3.6.1 Random Copolymers.

3.6.2 Alternating Copolymers.

3.6.3 Block Copolymers.

3.7 The Solution Structure of Polymers.

3.7.1 Polymer Chain Conformation.

3.7.2 Intermolecular Interactions in Polymers.

4. The Solid–State NMR of Polymers.

4.1 Introduction.

4.2 Chain Conformation in Polymers.

4.2.1 Semicrystalline Polymers.

4.2.1.1 Solid–State Phase Transitions.

4.2.2 Amorphous Polymers.

4.2.3 Elastomers.

4.2.4 Reactivity and Curing in Polymers.

4.3 Structure and Morphology in Polymers.

4.3.1 Introduction.

4.3.2 Spin Diffusion and Polymer Morphology.

4.3.2.1 Spin Diffusion and Interfaces.

4.3.2.2 Spin Diffusion and Coefficients.

4.3.2.3 Polarization Gradients for Measuring Spin Diffusion.

4.3.2.4 Proton Relaxation and Morphology.

4.3.3 Semicrystalline Polymers.

4.3.4 Block Copolymers.

4.3.5 Multiphase Polymers.

4.3.6 Polymer Blends.

5. The Dynamics of Polymers.

5.1 Introduction.

5.2 Chain Motion of Polymers in Solution.

5.2.1 Modeling the Molecular Dynamics of Polymers in Solution.

5.2.2 Relaxation Measurements in Solution.

5.2.3 NMR Relaxation Measurements in Solution.

5.2.4 The Relaxation of Polymers in Solution.

5.3 NMR Relaxation in the Solid State.

5.3.1 Introduction.

5.3.2 NMR Relaxation in Solid Polymers.

5.3.3 Spin Exchange in Solid Polymers.

5.3.4 Polymer Dynamics and Lineshapes.

5.3.4.1 Wideline Deuterium NMR.

5.3.4.2 Chemical Shift Anisotropy and Polymer Dynamics.

5.3.4.3 Dipolar Lineshapes and Polymer Dynamics.

O autorze

PETER A. MIRAU is Senior Research Scientist in the Nonmetallic Materials Division (Polymer Branch) at the Air Force Research Laboratories in Dayton, Ohio.

Blurb

A comprehensive introduction to an important analytical technique

NMR spectroscopy has emerged as an important analytical method in polymer science. The intense interest in NMR has led to the development of commonly used practical methods, as well as complex and esoteric applications. This makes understanding and appreciating the power of NMR somewhat daunting to students and researchers from other fields.

A Practical Guide to Understanding the NMR of Polymers provides an introductory framework for understanding the theory and practical applications of NMR in polymer science. This text was created specifically to provide readers with the essential concepts and the practical means for the analysis of polymers, including:

• The basic NMR phenomena, including chemical shifts, spin–spin coupling, NMR relaxation, multidimensional (nD) NMR, and solid–state NMR, with special focus given to NMR parameters that are particularly important for the NMR of polymers
• Experimental methods for polymer characterization, including practical tips for NMR sample preparation, data collection, and analysis
• Solution characterization of polymers, including how changes in polymer microstructure lead to identifiable features in the NMR spectra
• Solid–state NMR as a method for analyses of polymers such as the characterization of insoluble materials or monitoring of reactivity and curing of polymers
• The dynamics of polymers both in solution and the solid state

With clear, accessible language, numerous experimental examples, and helpful references, A Practical Guide to Understanding the NMR of Polymers gives advanced students and researchers in polymer and analytical chemistry a comprehensive introduction to this important technique.