POLYOLS WITH POLYESTER-AMIDE STRUCTURE CONTAINING MESOGENIC STRUCTURAL UNITS FOR SEMI-FLEXIBLE POLYURETHANE FOAMS AND PROCESS FOR PREPARING THE SAME

The invention relates to a process for preparing polyols with polyester-amide structure containing mesogenic structural units for semi-flexible polyurethane foams. According to the invention, the process comprises the successive stages of: 1. PET glycolysis in the presence of a mixture of diethylene glycol and polyethylene glycol 600, in a molar ratio of 50...100 : 0...50, in a PET : glycols molar ratio of 1 : 3...4.5, in the presence of 5% molar 1,8-Diazabicyclo[5.4.0]undec-7-ene catalyst in relation with the PET, at a temperature of 190°C, while stirring, in nitrogen atmosphere and total reflux, for 3...4 h, 2. aminolysis with an aromatic diamine, in the presence of 5% molar 1,5,7-Triazabicyclo[4.4.0]dec-5-ene catalyst in relation with the PET, in the same conditions, for 5 h, 3. esterification of the reaction mixture with adipic acid, in a molar ratio of 1.5...2 in relation with the PET, in the presence of titanium tetraisopropoxide as catalyst, at a temperature of 200...205°C, for 4...6 h, to result in polyols with an average molecular mass of 630...2000 g/mole, an acidity index of 1.5...3.5 mg KOH/g, a hydroxyl index of 50...180 mg KOH/g, functionality 2 and dynamic viscosity at 25°C of 7000...15000 cP.