Telechelic oligomers made from ethylene oxide and phosphoric acid.
Structure and transformation into organoaluminum polymers (in English)
Polimery 2004, No 6, 389
The reaction of phosphoric acid with ethylene oxide (EOX) in organic solvents or water has been studied at -5°C to +30°C by means of NMR and MALDI-TOF spectroscopy. Linear telechelic oligomers comprising 4-25 ethylene oxide monomeric units and 3 terminal hydroxyl groups were found to be the main products of this reaction. Side products include cyclic esters, condensation products containing 2-3 phosphorus atoms in the chain and oligodiols. The esters are stable at temperatures up to 170°C; and in water exhibit strong resistance to hydrolysis up to approx. 80°C. Aqueous medium at 100°C in presence of aluminum oxohydroxide in the form of boehmite leads to hydrolysis of one ester bond, in situ yielding a diester, which reacts with the boehmite to form hybrid phosphate-alumoxane structures; with molar ratio of P:Al in such polymers of approx. 1.1. Atransparent colloidal dispersion with abroad molecular weight spread of the polymer component and low limiting viscosity number (about 0.002 cm3/g) is formed. Lowest molecular weight fractions form true solutions in water and DMSO.
Keywords: phosphoric acid, ethylene oxide, oligomeric phosphates, boehmite, hybrid phosphate-alumoxane polymers, chemical structure, MALDI TOF
Telechelic oligomers made from ethylene oxide and phosphoric acid. Structure and transformation into organoaluminum polymers (in English)