The morphologies of different commercial forms of the copolymer of tetrafluoroethylene with hexafluoropropylene (FEP) were investigated by thermomechanical analysis. Both granules and powders of FEPs have similar morphologies, but different temperatures for phase transitions. Irradiation reduces the crystallinity of the FEPs and results in a transformation from the crystalline to the amorphous form. After heating of various forms of FEP irradiated at 77 K, there are three intense maxima of radiothermoluminescence in the temperature ranges: 150–144, 174–167, and 210–206 K. The nature of the radiothermoluminescence and the phase transitions of the FEPs as a result of gamma—irradiation are discussed.

The structure and properties of active powder of discretely devulcanized rubber (APDDR) produced by the technique of high-temperature shear-induced grinding in rotary dispergators is studied. The morphology of APDDR particles, including such particles after mixing with hot bitumen, is examined by electron and atomic force microscopy. Rheological tests of rubber-modified bitumens demonstrate the efficiency of APDDR particles as an efficient modifier of bitumen binders and asphalt concrete pavements intended for service in different climatic zones under extreme loadings. The data are confirmed by field tests of modified asphalt concretes.

Key aspects of tire-rubber-waste collection, accumulation, processing, and further application have been examined. Special attention has been paid to application of ground tire rubber as a...

For the first time, by atomic force microscopy (AFM) methods, micro- and nanofragments of micronized powder elastomeric modifier (PEM) formed at the short-term (3 min at 160 °C) interaction of PEM with hot bitumen have been demonstrated. It is the technology of high-temperature shear-induced grinding of a worn-out tire’s crumb rubber or its co-grinding with styrene–butadiene–styrene (SBS) block copolymer which provides the creation of the PEM structure inclined to rapid degradation in hot bitumen. The formation just after the preparation process of a new structure of a modified binder, more resistant to external effects, is supported by the data of rheological tests. Performance tests for a modified binder using Superpave standard adopted by the road industry for bituminous binders showed an extended temperature range, resistance to rutting, and low-temperature and fatigue cracking. The better resistance to low-temperature and fatigue cracking is certainly related to energy absorption and crack growth stopping in the presence of micron and submicron resilient PEM fragments in accordance with the mechanism of increasing impact toughness in plastics.

Structural features of crumb rubber (CR) particles obtained by grinding on rollers and ultra-disperse powder elastomeric modifiers (PEM) obtained by high-temperature shear-induced grinding (HTSG) of CR or co-grinding with butadiene styrene thermoplastic elastomer (SBS) have been studied by electron and optical microscopy methods. Samples of modified bitumen were obtained at different mixing times (1–40 min) in a wide temperature range (120–180 °C). The products of interaction of PEM with hot bitumen precipitated on filters when washed with solvent from modified bitumen (MB) were studied by scanning electron microscopy (SEM). The self-similarity PEM particles and PEM breakdown fragments in bitumen up to the size of 100–200 nm were noted. The rapid (for 1 min) decomposition of PEM particles into fragments is shown, which is due to the specific structure formed as a result of HTSG. It has been suggested that this fragmentation may be caused by bitumen penetrating deep into the porous particle and breaking it, due to differently directed swelling pressure and precede the classical swelling associated with the penetration of solvent between rubber macromolecules, or occur concurrently with it.