The use of terephthalic acid diamide in rubbers based on NBR-40

In the present work, the kinetics of aminolytic degradation of polyethylene terephthalate with a mixture of amino alcohols (monoethanolamine and triethanolamine) was studied to obtain terephthalic acid diamide (N, N'-bis (2-hydroxyethyl) terephthalamide).The degradation reaction was carried out at atmospheric pressure and periodically stirring the reaction mass, followed by purification of the product by recrystallization.The dependence of the yield of the target product (N, N'-bis (2-hydroxyethyl) terephthalamide) on the reaction time and temperature, as well as on the ratio of the components, was revealed. The possibility of using diamide as one of the components of rubbers to expand the ingredient base in the rubber industry is considered. The effect of the obtained diamide on the kinetics of vulcanization of rubbers based on nitrile butadiene rubber (NBR-40) was studied, and the physicochemical and physicomechanical properties of the obtained vulcanizates were examined. In a similar way, the effect of an oligomer obtained by polycondensation of this terephthalic acid diamide was studied. The choice of SKN-40 rubber as the basis is due to the high polarity of the rubber and its good compatibility with the obtained terephthalic acid diamide and its oligomer.The accelerating effect of terephthalic acid diamide in combination with 2-mercaptobenzothiazole (MBT) on sulfur vulcanization of rubbers based on NBR-40 was revealed. The time to reach the optimum vulcanization is reduced by 4 min. In the case of using only terephthalic acid diamide, without the use of common accelerators, the optimum point of vulcanization shifts toward a longer time.In the case of using only terephthalic acid diamide, without the use of common accelerators, the optimum point of vulcanization shifts toward a longer time. Introduction diamide of terephthalic acid or its oligomer results in a change of physical and mechanical properties of the rubber - strength at break and elongation at break. The kinetics of the swelling of the resulting rubbers in toluene and gasoline was studied for four hundred hours. A decrease in the degree of swelling of vulcanizates in gasoline was observed with the introduction of terephthalic acid diamide instead of the zinc oxide vulcanization activator. Possible options for further application and use of the obtained terephthalic acid amide and its oligomer are considered.