STRUCTURE AND PROPERTIES OF SECONDARY polyolefinS
The article considers environmental and technological aspects of the secondary application of details made of polyethylene and polypropylene, by their recycling after the end of term of operation of pipelines, molded products. Provides comparative physical and mechanical properties of primary and secondary polyolefins, their relationship with the crystal structure: thermomechanical curves, stress relaxation. Describes the temperature dependence of the zero viscosity, the role of molecular mass; the dependence of the softening temperature of the degree of the polymers crystallinity. Shows the effect of the multiplicity of the recycling of polyolefins their physical-mechanical properties: strength, hardness, deformation. Provides a technological scheme for the recycling of polyolefins in granules. References - 14 ref.