Macromolecular materials basic properties

Polymers exhibit a range of architectures and unique properties, the study of which represents a major core area of polymer science. Although this book assumes that the reader is familiar with some of the basic concepts of polymer science, such as the structures of common macromolecular materials (polystyrene, polyisoprene, etc.), additional knowledge is certainly desirable for an appreciation of much of the research described and the challenges for the future. In this section, we briefly cover some key points for the benefit of readers unfamiliar with the areas that are relevant to the discussions in subsequent chapters. For detailed background material the reader is referred to the many excellent introductory and advanced books on polymer sdence and the recent literature dted in this section ]7, 37-42]. 

However, even the complete understanding of these areas will not suffice to reap the full benefits embedded in the macromolecular nature of polymeric materials, which are inherent in the naturally occurring and synthetic polymeric building blocks. For that, a priori quantitative prediction of product properties, made of yet nonexistent chains or combinations of chains of different monomeric building blocks from basic principles, requiring information of only the macromolecular structure and processing conditions, is needed. 

This section attempts to examine macromolecular geometry, and in particular dendritic surface characteristics, from the perspectives of self-similarity and surface irregularity, or complexity, which are fundamental properties of basic fractal objects. It is further suggested that analyses of dendritic surface fractality can lead to a greater understanding of molecule/solvent/dendrimer interactions based on analogous examinations of other materials (e.g., porous silica and chemically reactive surfaces such as found in heterogeneous catalysts). 52 ... 

In the preceding discussions, the basic concepts for the conversion of monomers into polymers by chain addition polymerization mechanisms were presented. The cycle of chain birth, growth, and death is common among all forms of chain polymerization. In the case of controlled polymerization, chain death can be avoided and under these conditions macromolecules with controlled architecture can be readily prepared. New controlled polymerizations have allowed for and will continue to enable precision macromolecular syntheses that endow these materials with advanced property profiles. Many contemporary polymer synthesis efforts are focused on these chain polymerization methods. However, there exists a large class of polymers that are synthesized in a... 

On the other hand, the mechanical properties also depend on the materials molecular composition and structure, i.e., intrinsic parameters. Intrinsic parameters are, for instance, chemical composition or constitution, configuration, conformation, chain cross section, entanglement molecular weight, free volume, chain stiffness, macromolecular mobility, crystallinity, and others [4, 16, 17]. Chain length and chain length distribution (or molecular weight M ) have a basic influence on mechanical properties, which is illustrated in Fig. 1.17. Three regions can be identified ... 

In this chapter we will shortly summarize the nonlinear optical properties of macromolecular systems and some of the main experimental techniques for their optical characterization. Some basic optoelectronic patterns will be reported in order to give a brief account of the advances in the realization of active waveguide systems and telecommunication devices based on organic materials. The main optoelectronic devices based on nonlinear optical properties of chromophores in polymeric and hybrid matrices will be illustrated. In particular Mach-Zehnder modulators, microring resonators, switches and wavelength filters will be reviewed. 

In Both plasticized (semi-rigid and flexible) PVC materials as well as PVC in solutions, the rate of their thermal degradation and effective stabilization are caused by essentially different fundamental phenomena in comparison to aging of PVC in absence of the solvent Both stmcture and macromolecular dynamics render the significant influence on its stability, i.e. chemical nature of the solvent (plasticizer), its basicity, specific and non-specific solvation, degree of PVC in a solution (solubility), segmental mobility of macromolecules, thermodynamic properties of the solvent (plasticizer), formation of associates, aggregates, etc. 

As it has been noted above, at present it is generally acknowledged [2], that macromolecular formations and polymer systems are always natural nanostructural systems in virtue of their structure features. In this connection the question of using this feature for polymeric materials properties and operating characteristics improvement arises. It is obvious enough that for structure-properties relationships receiving the quantitative nanostructural model of the indicated materials is necessary. It is also obvious that if the dependence of specific property on material structure state is unequivocal, then there will be quite sufficient modes to achieve this state. The cluster model of such state [3-5] is the most suitable for polymers amorphous state structure description. It has been shown, that this model basic structural element (cluster) is nanoparticles (nanocluster) (see Section 15.1). The cluster model was used successfully for cross-linked polymers structure and properties description [61]. Therefore, the authors of Ref [62] fulfilled nanostmetures regulation modes and of the latter influence on rarely cross-linked epoxy polymer properties study within the frameworks of the indicated model. 

Polymer physics is a key part of macromolecular science. This textbook presents the elements of this important branch of materials science in the style of a series of lectures." The main focus lays on the concepts, rather than on experimental techniques and theo retical methods. Written for graduate students of physics, materials science and chemical engineering, as well as for researchers in academia and industry entering this fielcJ, the book introduces and discusses the basic phenomena that lead to the peculiar physical properties of polymeric systems. 

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