New Concepts in Polymer Science - Böcker

Results of the studies of two leading Russian researchers in the field as well as of other Russian and foreign specialists are presented in this book. The nature and development of two physical processes – glass transition and crystallization determinig low-temperature behaviour of elastomers are under consideration in connection with the structure and composition of elastomeric materials. The effects of deformation, pressure and temperature on these processes are viewed. The contribution of different factors in frost-resistance of elastomeric materials and articles is discussed as well.Specific features of low-temperature behaviour of all existent rubbers are systemized. Furthermore, the possibilities of increasing the frost-resistance of different types of elastomeric materials and articles by means of optimization of composition and design are considered.

This volume is devoted to the developments in the branch of polymer chemistry which deals with immobilized systems. These systems are widely used in fields connected with metabolism in humans, animals, plants and micro-organisms. The study of these artificial immobilized systems permits the understanding and design of the function and behaviour of natural substances in living organisms. The book contains the latest achievements in the field of synthesis of polymeric derivatives of different natural substances such as: proteins; peptides; amino acids; poly- and monosaccharides; nucleic acids; nucleosides; nucleotides; coenzymes; vitamines; alkaloids; antibiotics; steroids; hormones; and others. Special attention is given to natural and synthetic carriers and the influence of their chemical structure on the efficiency of systems obtained. This work should be of value and interest to researchers in the field of polymer chemistry, biotechnology and genetic engineering, medical chemistry, bio-organic chemistry and enzymology.

The basic problem of polymer physics is obtaining ‘structure-properties’ correlations for their future application for practical purposes. However, these cannot be obtained without the development of a quantitative model of the polymer structure.This problem has been actively investigated during the last 45 years, which resulted in obtaining a great amount of experimental (mostly indirect) proofs of existence of the local order in the polymer amorphous state. Now, the time has come for creating a structural model of polymer basing based on the local order ideas. The cluster model, as presented in this monograph, of the polymer amorphous state structure represents the realization of such attempts. The development of this cluster model is based on well-known experimental observation: the behavior of glassy polymers in the area of stimulated high-elasticity plateau is described in the framework of rubber elasticity concepts. This gives an opportunity to present the local order (cluster) zone as a multifunctional entanglement of the physical network consisting of several collinear closely packed segments of different macromolecules (the amorphous analogue of crystallite with extended chains) and surrounded by a packless matrix. An independent method for assessing local order zone fraction in the structure has been elaborated. Segment length in the cluster equals the length of the chain statistical segment that gives a correlation between molecular and structural parameters of the polymer. Application of the cluster model allowed description and obtaining of analytical ‘structure-properties’ correlations for many processes proceeding in polymers: elasticity, yielding, degradation, transport, some thermodynamic processes, structural relaxation, plasticization, structural stabilization at thermo-oxidative degradation, etc. The relation between the cluster model and some modern physical concepts, for instance fractal analysis, fluctuation free volume kinetic