POLYESTER-ETHER POLYOL / MONTMORILLONITE COMPOSITES FOR (NANO)COMPOSITE SEMI-FLEXIBLE POLYURETHANE FOAMS AND PROCESS FOR PREPARING THE SAME

The invention relates to a process for preparing polyester-ether polyol/montmorillonite composites for semiflexible (nano)composite polyurethane foams. According to the invention, the process comprises the following successive stages: 1. dispersing the montmorillonite in a mixture of diethylene glycol and polyethylene glycol 600, in a molar ratios of 86...91 : 9...14, in the presence of 10...15% imidazonium salt, at a temperature of 150°C, while stirring, under nitrogen atmosphere, for 1...2 h, 2. glycolysis of PET wastes, in the presence of the montmorillonite/diethylene glycol and polyethylene glycol 600 mixture, at a molar ratio of 1 : 2.3...3.4, at a maximum temperature of 185...190°C, for 3...4 h and 3. esterification of the reaction mixture with adipic acid, in a molar ratio of 1 : 0.67...1.5 in relation with the PET, in the presence of a catalyst, such as titanium tetraisopropoxide, in an amount of 0.15% molar in relation with the total amount of acids, while stirring, under nitrogen atmosphere, at a temperature of 200...205°C, for 4...5 h, forming polyester-ether polyol composites having an average molecular mass of 1500...2000 g/mole, an acidity index of 1...5 mg KOH/g and dynamic viscosities of 5000...10000 cP at 25°C.