Spectroscopy of Polymers

J.L. Koenig

• Publisher: Elsevier Science
• Year: 1999
• Print ISBN: 9780444100313
• eBook ISBN: 9780080541570
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Spectroscopy & Spectrum Analysis
• Index: Technology & Engineering

This revised and updated Second Edition of the best-selling reference/text is essential reading for students and scientists who seek a thorough and practical introduction to the field of polymer spectroscopy. Eleven chapters cover the fundamental aspects and experimental applications of the primary spectroscopic methods. The advantages and disadvantages of the various techniques for particular polymer systems are also discussed. The goal of the author is not to make the reader an expert in the field, but rather to provide enough information about the different spectroscopic methods that the reader can determine how the available techniques can be used to solve a particular polymer problem. This Second Edition contains new and updated information on techniques in IR and NMR, as well as an all-new chapter on Mass Spectrometry.

Chapter 1

Theory of polymer characterization

The primary motivation for determining the molecular structure of a polymer chain is to relate the structures to the performance properties of the polymer in end use. If the polymer chains are completely characterized and the structural basis of its properties are known, the polymerization reaction can be optimized and controlled to produce the optimum properties from the particular chemical system.

Elements of polymer structure

The following basic terms are used for defining a polymer structure.

• The composition (or constitution) of a molecule defines the nature of the atoms and the type of bonding irrespective of the spatial arrangement.

• The configuration of chemical groups characterizes the chemical state of a polymer. Different configurations constitute different chemical entities and cannot be interconverted into one another without rupture of chemical bonds.

• The conformation of chemical groups characterizes the geometrical state of a polymer. Different conformations of a polymer can be produced by rotation about single bonds without rupture of chemical bonds. Changes in conformation arise from physical considerations such as temperature, pressure, or stress and strain.

Polymer chains are made up of sequences of chemical repeating units that may be arranged regularly or irregularly on the backbone.

• The chemical microstructure is defined as the internal arrangement of the different chemical structures or sequences on the polymer chain.

Polymers can exhibit phase transitions and show a number of fundamental spatial distributed macroconformations that define the crystalline and amorphous phases.

• The polymer morphology defines the intermolecular packing of the polymer molecules as crystals or spherulites in the bulk.

• Polymer chains can exhibit different chain topologies where topology describes the molecular packing of the chains. Chain alignments, orientation and entanglements are topologic features.

The mechanical properties such as modulus, tenacity, and yield are propertieswhich depend on the dynamics of the polymer chain.

• The molecular motion depends on the intramolecular and intermolecular constraints imposed on the structure of the chain and the non-bonded neighbors in the vicinity.

From a structural point of view polymers are chainlike molecules.

X–A–A–A–A–A–A–A–A–A–A–A–A–A–A–A–A–A–Y

The structural elements of an ideal polymer molecule with a single structural repeating unit can be represented by the molecular formula, X(A)_nY, where A represents the repeating unit of the polymer molecule and n is the number of repeating units of A, X and Y are the end-group units which are chemically different from A. The number of connected repeating units, n, can range from 2 to greater than 100,000. The chemical nature of the repeating unit A determines the chemical properties of the polymer. The chemical structure of the repeating unit can be very simple (e.g., CH₂ for polyethylene) or very complicated.

The end-group units X and Y can be substantially different in chemical structure from A or very similar depending on the nature of the polymerization process.

Structural variations within the chain can be ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Preface to the second edition
• Chapter 1: Theory of polymer characterization
• Chapter 2: Vibrational spectroscopy of polymers
• Chapter 3: Experimental IR spectroscopy of polymers
• Chapter 4: Applications of IR spectroscopy to polymers
• Chapter 5: Raman spectroscopy of polymers
• Chapter 6: High resolution NMR spectroscopy of polymers in solution
• Chapter 7: Applications of high-resolution solution NMR
• Chapter 8: High-resolution NMR spectroscopy of solid polymers
• Chapter 9: Applications of high-resolution solid-state NMR spectroscopy to polymers
• Chapter 10: Mass spectrometry of polymers
• Subject index