This paper deals with description of polymeric materials and the division by origin, by the type of repeating units in a macromolecule, with structure of the macromolecules and with the degree of ordering in macromolecule. Also this paper deals with analyzing connection between the structure, properties and processing methods of thermoplasts, thermosetting and elastomers, the definition and properties of thermoplastic materials, also degree of polymerization, crystallization and deformation, tacticity and finally blending. This paper contains analyzing the influence of temperature on mechanical properties (plastic, elastic and viscoelastic deformation), dependence of tensile stress – elongation and relaxation properties, also comparing the application of plastomers and rubber in Europe for 2017. Finally, examples of mechanical applications of thermoplasts and trends in their development and application, and the advantages and disadvantages of thermoplasts with some other materials.