Mechanisms of Ionic Polymerization: Current Problems

ISBN-13: 9781468483949 / Angielski / Miękka / 2012 / 316 str.

B. L. Erusalimskii

Opis

In the last twenty years the literature on the processes of ionic polymerization has reached such a level that there is not a single question which is not covered by the information contained in the many monographs, reference books, and textbooks in this field. It is easy for the interested reader to find sources for in-depth study, for a superficial acquaintance with the fundamentals of the subject or with the general features of these processes. At the same time the field is being continually enriched by new facts which have not only broadened the data base but which influence existing concepts on the mechanisms of these reactions. Such influences often touch the very foundations of these concepts, i. e., they go beyond simple descriptions of the structure of the pre-reaction states or earlier schemes. It is therefore appropriate to attempt a critical appraisal of the modern views on the mechanisms of formation of macro molecules in ionic systems which envisages, so far as is possible, the differentiating of fundamental and hypothetical conclusions or concepts. With this in mind we have preferred to address ourselves to the reader who is already quite well acquainted with the general litera ture. This has allowed us to dispense with detailed introductions to the questions discussed and to limit ourselves to brief comments on the fundamentals of the subject."

Spis treści

1: Characteristics of Ionic Polymerization Processes.- 1.1. Anionic Systems.- 1.2. Cationic Systems.- 1.3. Systems Based on Transition Metals.- 1.3.1. Ziegler-Natta Catalysts.- 1.3.2. ?-Allyl Complexes.- References.- 2: The Informativeness of Research Methods into Ionic Active Sites.- 2.1. Electrochemical Studies.- 2.1.1. Anionic Systems.- 2.1.2. Cationic Systems.- 2.2. Spectroscopic Studies.- 2.2.1. UV Spectroscopy.- 2.2.2. IR Spectroscopy.- 2.2.3. NMR Spectroscopy.- 2.2.3.1. Allyl Compounds.- 2.2.3.2. Derivatives of Unsaturated Monomers and Their Models.- 2.2.3.3. Ziegler-Natta Catalysts.- 2.3. Quantum-Chemical Studies.- 2.3.1. The Problem of Modelling in the Study of Ionic Systems Using Quantum-Chemical Methods.- 2.3.2. The Basic Approaches and Examples of Their Application.- 2.3.2.1. Series of Compounds.- 2.3.2.2. Individual Compounds.- 2.3.2.3. Multicomponent Systems.- 2.3.3. Summary.- References.- 3: General Questions on the Problem of Multicenteredness.- 3.1. Types of Multicentered Systems and Forms of Their Corresponding Active Sites.- 3.1.1. Dissociation of Aggregates.- 3.1.2. Ionic Dissociation.- 3.1.3. Intermolecular Complex Formation.- 3.1.4. Intramolecular Complex Formation.- 3.1.5. Isomerization of Active Sites.- 3.2. Overall and Individual Effects.- 3.2.1. Kinetic Features of Polymerization Reactions.- 3.2.2. Molecular Mass Distribution in Polymers.- 3.2.3. Structural Features of Macromolecules.- 3.3. The Role of Multicenteredness in Real Processes.- 3.4. Multicenteredness in Copolymerization Processes.- 3.4.1. The Aggregated State of Active Sites.- 3.4.2. Ion Pairs and Free Ions.- 3.4.3. Complex Formation with External Reagents.- 3.4.4. Intramolecular Effects.- 3.4.5. Isomerization.- References.- 4: The Reactivity of Active Sites and Monomers in Homogeneous Ionic Systems.- 4.1. The Relative Reactivity of Growing Chains.- 4.1.1. The Role of the State and the Environment of Growing Mn*Y Chains.- 4.1.1.1. Organolithium Growing Chains and Their Associates.- 4.1.1.2. Complexes of Organolithium Active Sites in the Polymerization of Nonpolar Monomers.- 4.1.1.3. Anionic Chains in the Polymerization of Polar Monomers.- 4.1.1.4. The Activating Effect of Electron Donors on Organolithium Associates.- 4.1.1.5. The Activating Effect of Electron Acceptors on the Polymerization of Cationic Growing Chains.- 4.1.1.6. Influence of the Nature of the Reaction Medium.- 4.1.2. The Role of the Nature of the Y Component in the Growing Mn*Y Chains.- 4.1.2.1. The Influence of the Nature of the Central Atom of the Counterion.- 4.1.2.2. The Total Effect of the Central Atom and Ligands of the Y Component.- 4.1.3. The Role of the Nature of the Mn* Component in Growing Mn*Y Chains.- 4.1.4. Concluding Remarks.- 4.2. Reactivity of the Monomers.- 4.2.1. Unsaturated Monomers.- 4.2.1.1. The Principles of Selection and the Indices of Reactivity.- 4.2.1.2. Nonterminating Copolymerization Processes.- 4.2.1.3. Copolymerization in Processes with Termination.- References.- 5: The Problem of Stereospecificity.- 5.1. The Polymerization of Vinyl and Vinylidene Monomers.- 5.1.1. Nonpolar Monomers.- 5.1.1.1. Propylene.- 5.1.1.2. Styrene Monomers.- 5.1.2. Polar Monomers.- 5.1.2.1. Methacrylates and Related Monomers.- 5.1.2.2. Vinylpyridines.- 5.1.2.3. Alkenyl Ethers.- 5.2. Diene Monomers.- 5.2.1. Polymerization in Cationic Systems.- 5.2.2. Polymerization in Anionic Systems.- 5.2.2.1. Butadiene and Isoprene.- 5.2.2.2. Diene Phenyl Derivatives.- 5.2.3. Polymerization in Systems with Transition Metals.- References.- 6: Conclusion.- References.