Physikalische charakterisierung von copolymeren und polymergemischen

The characterization of binary copolymers is discussed on the basis of NMR and IR spectroscopic measurements carried out with single molecules. The physical investigation of single molecules, however, provides only limited information concerning the nature of the solid substance. A study of the structure of the condensed state is of greater value as regards the physical characterization of copolymers and polymer mixtures. Mechanical, IR spectroscopic, X-ray, calorimetric and electron microscopic methods are most suitable for this purpose. Consideration is first given to monophase systems. The properties of these systems are a complex synthesis of the properties of the components. Copolymers and polymer mixtures of mutually soluble, non-crystalline components are monophase systems; these include all statistical copolymers provided that no crystallization takes place even when a very large excess of one component is present. In contrast to these homogeneous systems the properties of the components forming the phases in bi- and polyphase systems are apparent. Mixtures of mutually insoluble polymers, block and graft copolymers whose components form sufficiently large, separated blocks, and partially crystalline polymers behave as heterogeneous systems. The two components in heterogeneous binary systems are normally present as coherent and incoherent phases. Examples of the different systems are discussed.