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

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.

Optimization of Structure of Soft Block for Design of Adaptive Polyurethanes

A synthesis of new di-and triblock polyurethane thermoplastic copolymers containing different mass ratio of two crystallizing blocks - poly (1,4-butylene glycol) adipate and poly-ε-caprolactone diols was developed. Using combination of danamometric analysis, IR-spectroscopy, differential scanning calorimetry and X-ray diffraction, the effect of the soft block composition and crystallization conditions on crystal structure and thermal behavior of the obtained polymers have been studied. For the triblock copolymers we have shown a possibility of control the kinetics of material hardening and final mechanical characteristics due to the mutual influence of polydiols during crystallization. In the result, the second crystallizing component allows to control amount, structure and quality of crystalline domains in polyurethanes by variation of crystallization conditions.

Investigation by TGA, DSC and DMA Urethane-Imide Copolymers with High Content of Hard Imide Blocks

Poly (diethylene glycol) adipate diol, tolylene-2,4-diisocyanate, 1,3-bis (3',4-dicarboxylphenoxy) benzene and 1,4-bis (4'-aminophenoxy) biphenyl were used as monomers to form statistical copoly (urethane-imide) s with variable content of imide blocks (from 37 to 65% (wt)). The copolymers imide blocks on the Tg and Tm values relative content increasing effect was traced, which is associated with the phase separation of hard imide and flexible polyester blocks in the systems studied.

New Polyurethane Urea Thermoplastic Elastomers with Controlled Mechanical and Thermal Properties for Medical Applications

The method of synthesis of new polyurethane urea thermoplastic elastomers with controlled physical network density by varying the crystallization rate of the soft block and the structure of the interphase has been developed. Fine-tuning of morphology and mechanical properties allows to desighn adaptive materials with shape memory. By combination of calorimetric and X-ray diffraction methods, the influence of chemical nature of diaisocyanates and the ratio of two types of crystallizable blocks, polybutylene glycol adipate diol (PBA) and poly-ε-caprolactone diol (PCL), on the structure and termal behavior of the thermoplastic elastomers has been studied.