Investigation of the Effect of Mono- and Diurethane Units on the Deformation and Strength Properties of Polyurethanimides

The effect of synthesis conditions for macrodiisocyanate (temperature, reaction duration, ratio of components) based on poly(diethylene glycol adipate) (Mn = 2.5 × 103) and 2,4-toluene diisocyanate on the composition of the reaction products has been studied. The number of mono- and diurethane units was estimated using proton magnetic resonance spectra. It was found that carrying out the synthesis at 80°C using an eight-fold excess of 2,4-toluene diisocyanate results in the production of a macrodiisocyanate with a diurethane unit content of less than 1 mol %. Based on the isolated macrodiisocyanate, a fusible polyurethanimide, superior in elasticity to the unmodified analogue, was prepared.