The syntheses of poly (diethylene glycol adipate) in low-intensity ultrasound

Abstract

Poly (diethylene glycol adipate) is an important product of chemical technology. Several grades of polyesters (P-9, P-9A) are produced in the industry, in which poly(diethylene glycol adipate) is the main component. These composites are used in production of binders of mixed rocket solid fuels, as well as consumer goods. Poly(diethylene glycol adipate) is obtained by polycondensation of diethylene glycol and adipic acid. Usually, the polycondensation is carried out using catalysts. The use of catalysts complicates this process: requires further purification process or in solvent free system might slow reaction rate due to the limiting diffusion between reactants and mass transfer limitations. Therefore, it was proposed to use low-intensity ultrasound, which allows to influence the kinetics of the process without complicating the system. In this work, the reaction of polycondensation of diethylene glycol and adipic acid in low-intensity ultrasound was studied. The results of applying low-intensity ultrasound to the preparation of poly(diethylene glycol adipate) showed an increase in the reaction rate of the formation of a high-molecular compound and a change in the thermal regime. Application of low-intensity ultrasound provides synchronization of vibration and rotation of self-organizing dissipative structures, which leads to the decrease in energy consumption for mass transfer, thereby increasing the reaction rate. The low-intensity ultrasound demonstrated to be an effective method to intensify the polycondensation reaction.