Introduction to Polymer Spectroscopy

This book has grown out of several courses oflectures held at the University of Mainz in the years 1978 to 1981, at the Ecole Poly technique Federal, Lausanne, and at the University of Fribourg, Switzerland. The last two courses were held in the framework of the "3e Cycle" lectures in June 1981. According to this genesis, the emphasis of the book lies on a unified and concise approach to introducing polymer spectroscopy rather than on completeness which, by the way, could hardly be achieved in a single volume. In contrast to other books on this subject, equal weight is given to electronic spectroscopy, vibrational spectroscopy and spin resonance techniques. The electronic properties of polymers have been increasingly investigated in the last ten years; until recently, however, these studies and the spectroscopic methods applied have not generally been considered as part of polymer spectroscopy. The increasing use of electronic spectroscopy by polymer researchers, on the other hand, shows that this type of spectroscopy provides efficient tools for gaining insight into the properties of polymers which cannot be obtained by any other means.

A. General Introduction.- 1 Introduction.- 1.1 Definition of Polymer Spectroscopy.- 1.2 Information Obtained by Polymer Spectroscopy.- 1.3 Spectral Range.- 1.4 Remarks on the Choice of Examples for Applications.- 1.5 Bibliographic Notes.- References.- B. Electronic Spectroscopy.- 2 ESCA in Polymer Spectroscopy.- 2.1 Principle of the Method.- 2.2 The ESCA Spectrometer.- 2.3 Main Features of ESCA Spectra.- 2.4 Applications of Core-Electron Spectra.- 2.4.1 The Chemical Shift.- 2.4.2 Bulk and Surface Analysis.- 2.4.3 Examples of Bulk Analysis.- 2.4.4 Examples of Surface Analysis.- 2.5 ESCA Spectrum of Valence Electrons.- 2.5.1 Energy Bands.- 2.5.2 Energy Bands in Polymers.- 2.5.3 The Zero-Level Problem in ESCA Studies of Valence Bands.- 2.5.4 Examples of Valence Band Studies Using ESCA.- 2.6 Résumé of ESCA in Polymer Spectroscopy.- References.- 3 Absorption Spectroscopy in the Ultraviolet and Visible Regions.- 3.1 The far Ultraviolet (fUV).- 3.2 Absorption Spectroscopy in the Near Ultraviolet and Visible Regions.- 3.2.1 Spectral Region and Characteristic Transitions.- 3.2.2 Basic Principles of nUV/VIS Absorption Spectroscopy.- 3.2.2.1 Electronic Vibronic Spectra.- 3.2.2.2 Energy Level Diagrams.- 3.2.2.3 Intensity of Absorption Bands.- 3.2.2.4 The Franck-Condon Principle.- 3.2.3 Application of Lambert-Beer’s Law to Polymers.- 3.2.4 UV-Absorbing Polymers.- 3.2.5 Hypochromy in Polymers.- 3.2.6 Absorption by Molecules dissolved in Solid Polymers.- 3.3 Résumé of nUV/VIS-Absorption Spectroscopy.- References.- 4 Fluorescence- and Phosphorescence Spectroscopy of Polymers.- 4.1 Radiative and Radiationless Transitions.- 4.1.1 The Jablonski Diagram.- 4.1.2 Fluorescence.- 4.1.3 Internal Conversion and Inter-System Crossing.- 4.1.4 Phosphorescence.- 4.2 Experimental.- 4.3 Quantum efficiency, decay time and rate constants.- 4.4 Fluorescence in Polymers.- 4.4.1 Isolated and Crowded Fluorescent Groups.- 4.4.2 Fluorescence from Isolated Chromophores.- 4.4.3 Energy Transfer between Isolates Groups or Dissolved Molecules.- 4.4.4 Singlet Excitons.- 4.4.5 Excimer Fluorescence as a Probe in Polymer Studies.- 4.5 Phosphorescence in Polymers.- 4.5.1 The Phosphorescent Triplet State.- 4.5.2 Isolated Phosphorescent Groups.- 4.5.3 Triplet Excitons in Polymers.- 4.6 Résumé of Fluorescence and Phosphorescence Spectroscopy.- References.- C. Vibrational Spectroscopy.- 5 Vibrations.- 5.1 Introduction.- 5.2 The Harmonic Oscillator.- 5.3 Molecular Vibrations as Quantum Phenomena.- 5.4 General Remarks on the Interpretation of Vibrational Spectra.- 5.5 Symmetry and Fundamental Vibrations of One-dimensional Chain Molecules.- 5.6 Phonons.- References.- 6 Raman Spectroscopy.- 6.2 The Smekal-Raman Effect.- 6.3 Experimental.- 6.4 Examples of Laser-Raman Spectra of Synthetic Polymers.- 6.5 The Accordion Vibration.- 6.6 Resonance Raman Scattering.- 6.7 Résumé of Raman Spectroscopy of Polymers.- References.- 7 Infrared Spectroscopy of Polymers.- 7.1 Introduction.- 7.2 Absorption of Infrared Radiation.- 7.3 Experimental.- 7.3.1 IR-Absorption.- 7.3.2 IR Reflection and Emission.- 7.4 Interpretation of Polymer mIR Spectra.- 7.4.1 Empirical IR Spectroscopy.- 7.4.2 Examples of mIR Spectra of Linear Polymers.- 7.4.2.1 Poly(methylmethacrylate).- 7.4.2.2 Poly(isobutene) and amorphous polypropylene.- 7.4.2.3. Poly(vinylalcohol).- 7.4.2.4 Poly(acrylonitrile).- 7.4.2.5 Poly(caprolactam).- 7.4.3 Tacticity and Conformation in mIR Spectra.- 7.5 Applications of mIR Spectroscopy.- 7.5.1 General.- 7.5.2 Copolymers.- 7.5.3 Molar Mass.- 7.5.4 Branching.- 7.5.5 Carbon Double Bonds.- 7.5.6 Oxidation Processes.- 7.5.7 Corona and Plasma Treatment of Polymer Surfaces.- 7.5.8 Dissociation of Polymeric Acids and Other polymer-IR Studies.- 7.6 Résumé of mIR.- 7.7 Far-Infrared Spectroscopy of Polymers.- 7.7.1 Introduction.- 7.7.2 Chemical Applications.- 7.7.3 Phonons in fIR Spectra of Polymers.- 7.7.4 Inelastic Neutron Scattering (INS).- 7.7.5 Résumé of fIR + INS.- References.- D. Spin-Resonance Spectroscopy.- 8 Principles of Spin-Resonance Spectroscopy.- 8.1 Introduction.- 8.2 The Spin of Elementary Particles.- 8.3 Resonance Absorption.- 8.4 Spin-Resonance in Polymers.- References.- 9 Electron-Spin-Resonance (ESR) Spectroscopy of Polymers.- 9.1 General Characteristics of ESR Spectra.- 9.2 Experimental.- 9.3 Survey of Polymer-Specific Applications of ESR Spectroscopy.- 9.4 Polymerisation Studies by Means of ESR.- 9.5 Mechanically Formed Polymer Radicals.- 9.6 ESR of Radicals Formed by Radiation.- 9.7 Triplet States.- 9.8 Spin-Labels.- 9.9 Résumé.- References.- 10 Nuclear Magnetic Resonance (NMR) Spectroscopy of Polymers.- 10.1 The Origine of NMR Spectra.- 10.2 Experimental.- 10.3 High-Resolution 1H-NMR of Polymers.- 10.3.1 Applications.- 10.3.2 Tacticity Analysis.- 10.4 Broad-line NMR.- 10.5 Spin-Relaxation Times.- 10.6 Chemically Induced Dynamic Nuclear Spin Polarisation (CIDNP)...- 10.7 Résumé of 1H-NMR Spectroscopy.- 10.8 Polymer NMR Spectroscopy of 13C and Other Nuclei.- 10.8.1 Experimental.- 10.8.2 Solid Polymer 13C-NMR Spectroscopy.- 10.8.3 High Resolution 13C-NMR Spectroscopy of Polymer Solution.- 10.8.4 Other Nuclei.- 10.9 Résumé.- References.- E. Conclusion and Appendices.- Conclusion.- Appendix 1: Table of Polymers.- Appendix 2: List of Abbreviations.- Appendix 3: List of Elementary Constants Used in This Book.