USING POLYETHYLENE TEREPHTHALATE CHEMICAL PROCESSING PRODUCTS FOR BITUMEN MODIFICATION

Polyethylene terephthalate (PET) is one of the most widely used plastics in the world, whose mechanical and chemical recycling has been successfully mastered. Recently, PET chemical recicling products have attracted attention as potential additives to construction materials, including asphalt mixtures and concrete. The purpose of this research is to develop a way to chemically re- cycle PET waste to produce value-added products that can be used for bitumen modification. To achieve this goal, PET waste was subjected to an aminolysis reaction. The obtained terephthalic acid diamide underwent polycondensation in the melt obtaining oligoesteramide at different time of reaction. The structure of obtained products was confirmed through IR spectroscopy and visco- symetry. Bitumen BND 60/90 was modified by obtained oligoesteramides. The properties of the modified bitumens (per GOST 33137-2014, GOST 11506-73, GOST 18180-72, GOST 12801-98) demonstrated that the addition of oligoesteramides can increase ruting resistance, can expand the temperature operational range, and bitumen adhesion to minerals. Authors have established that the introduction of oligoesteramides does not cause any significant increase in the dynamic viscos- ity of bitumen (at 135 degrees C), which will help avoid technological difficulties when pumping bitumen. Also modified bitumenes have the resistance to thermal aging not lower than the base bitumen. It has been demonstrated that with an increase in the molecular weight of oligoesteramide and its content, both the shear resistance and adhesion of bitumen to the minerals increase, while the best adhesion is observed with crushed marble aggregate. Thus, the rational use of oligoesteramides prodused from PET waste be a promising way to solve environmental pollution problems, and opens up the possibility of obtaining products with high added value.