Specialty Polymers – serie

Examination of the early literature attests to the fact that the study of copolymerization was initiated when polymer science was in its infancy. It has continued to grow to a subject of major importance and has been a source of interest to both academic and industrialist alike. The wide spectrum of structures and properties available in the statistical copolymer has made this a fruitful field of exploration, but one particular and more restricted form which has held its own fascination for many is the limiting case of the strictly alternating copolymer. This is formed, in the ideal situation, when two monomers in a reaction mixture add consecutively to create a polymer chain with a regular {ABABAB} structure, irrespective of the monomer feed ratio. When this happens the resulting copolymer will always have the same composition, a feature which can be advantageous but also somewhat restrictive, as the ability to vary the properties is then limited. Within a series entitled Speciality Polymers it seems appropriate then to deal with this subject, particularly as no previous attempt has been made to draw together the various facets of alternating copolymerization into one volume. It also seems timely to present a more unified picture of the subject which will also illustrate the progress made.

Drawing a picture of the current situation of this new field, this volume both summarizes the past achievements and analyzes the present unsolved problems.

to the American Edition We are pleased that our modest work, published some time ago in Russian in Moscow* and which attracted the attention of polymer specialists,t will now be available to the EngJish- speaking audience of scientists - chemists, physicists, and technologists engaged in creating new types of polymer materi- als for modern technology and working on the fundamental prob- lems of the solid-state physics and structure of polymer- due to the initiative of Plenum Press. In polymer science, the 1980s were marked by the birth of a new field and a new scientific trend related to the dis- covery and study of a previously unknown class of polymers thermotropic liquid-crystalline polymers - and the further development of the fundamental theoretical concepts of the liquid-crystalline (mesomorphic) state of macromolecular com- pounds. This state is a phase state in thermodynamic equi- librium characterized by the anisotropy of the structure and properties as a result of one-dimensional or two-dimensional ordering.Such systems have an ordered but simultaneously labile structure which can easily be altered by mechanical, electrical, or magnetic fields; the polymer system then acquires unique physical and optical properties. These prop- erties, which are acquired in the liquid-crvstalline state, are then fixed in the solid at the operating temperatures. *N. A. Plate and V. P. Shibaev. Comb-Shaped Polymers and Li- quid Crystals [in RussianJ. Khimiya, Moscow (1980). tSee the review of this book by H. Mark in J. Polym. Sci. Polym. Lett. Ed. , 20, 139 (L982).

The study of the effects of dimensional ity and disorder on phase transitions, electronic transport, and superconductivity has become an important field of research in condensed matter physics. These effects are both classical and quantum mechanical in nature and are observed universally in urealu materials. What may at first glance seem a diverse collection of lectures which form the chapters of these proceedings is in fact, an attempt to demon­ strate the commonality, inter-relationship, and general applica­ bility of the phenomena of localization, percolation, and macro­ scopic quantum effects on electrical transport and superconduc­ tivity in disordered solids. The theory of these phenomena is presented in a complete, yet, self-contained fashion and the inter-relationship between the topics is emphasized. An extensive treatment of experimental results is also included, both those which have stimulated the theory as well as those that have confirmed it. Many of the phenomena investigated in this field also have technological significance. For example, the nature of electronic localization in metals in which one or more dimensions are con­ strained is very important when one attempts to predict the be­ havior of the metallic interconnects in ultra-miniature circuits.

The Advanced Study Institute on "Photoionization and Other Probes of Many-Electron Interactions" was held at the Centre "Les Cigales" in Carry-Ie-Rouet (France), from August 31st till September 13th 1975. The Institute was sponsored by the Scienti­ fic Affairs Division of NATO. The "Centre National de la Recher­ che Scientifique" (France) gave also partial support to the French participants and the National Science Foundation (U. S . A. ) to the American participants. A total of 18 lecturers, and 54 students selected among more than 120 applicants, attended the Institute. Over the last few years, substantial progress has been made in the experimental study of photon- or electron interactions with atoms. In particular, the g. rowing number of facilities created to use the synchrotron radiation makes now possible the realization of new types of experiments. The accumulation of new results showed clearly it was necessary to introduce electron correlations in the theoretical models in order to explain the existence and the probability of a large number of processes, in particular multiple processes. Thus large progress has also been made in the theore­ tical description of the excitation of the electronic systems and their interactions. It was the purpose of this Institute to bring together theoreticians and experimentalists in order to provide an opportunity to present in details the state of the art, in experiment as well as in theory, and to favor discussions on future experimen­ tal and theoretical studies.

Examination of the early literature attests to the fact that the study of copolymerization was initiated when polymer science was in its infancy. It has continued to grow to a subject of major importance and has been a source of interest to both academic and industrialist alike. The wide spectrum of structures and properties available in the statistical copolymer has made this a fruitful field of exploration, but one particular and more restricted form which has held its own fascination for many is the limiting case of the strictly alternating copolymer. This is formed, in the ideal situation, when two monomers in a reaction mixture add consecutively to create a polymer chain with a regular {ABABAB} structure, irrespective of the monomer feed ratio. When this happens the resulting copolymer will always have the same composition, a feature which can be advantageous but also somewhat restrictive, as the ability to vary the properties is then limited. Within a series entitled Speciality Polymers it seems appropriate then to deal with this subject, particularly as no previous attempt has been made to draw together the various facets of alternating copolymerization into one volume. It also seems timely to present a more unified picture of the subject which will also illustrate the progress made.