Ulteriori informazioni
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.
Sommario
1: Characteristics of Ionic Polymerization Processes.- 1.1. Anionic Systems.- 1.2. Cationic Systems.- 1.3. Systems Based on Transition Metals.- References.- 2: The Informativeness of Research Methods into Ionic Active Sites.- 2.1. Electrochemical Studies.- 2.2. Spectroscopic Studies.- 2.3. Quantum-Chemical Studies.- References.- 3: General Questions on the Problem of Multicenteredness.- 3.1. Types of Multicentered Systems and Forms of Their Corresponding Active Sites.- 3.2. Overall and Individual Effects.- 3.3. The Role of Multicenteredness in Real Processes.- 3.4. Multicenteredness in Copolymerization Processes.- References.- 4: The Reactivity of Active Sites and Monomers in Homogeneous Ionic Systems.- 4.1. The Relative Reactivity of Growing Chains.- 4.2. Reactivity of the Monomers.- References.- 5: The Problem of Stereospecificity.- 5.1. The Polymerization of Vinyl and Vinylidene Monomers.- 5.2. Diene Monomers.- References.- 6: Conclusion.- References.
