ABSTRACT:Reactions of trithiocyanuric acid with a large excess of ethylene oxide and propylene oxide in DMF solution and in the presence of triethylamine as catalyst were carried out. Trifunctional polyetherols containing an s-triazine ring were prepared. The structure of the products was confirmed by using elemental analysis, 1 H-NMR and IR techniques. Some of the physical properties and thermal stability of polyetherols were analyzed.
Reactions of 6-aminouracil with an excess of oxiranes (ethylene oxide and propylene oxide) in dimethylsulfoxide in the presence of triethylamine as a catalyst leads to polyetherols with a 1,3-pyrimidine ring. The products are analyzed using IR and 1 H-NMR spectroscopies. The physical properties and thermal stability of the prepared polyetherols are investigated.
Attempts of obtaining of polyurethane foams using polyetherols with 1,3-pyrimidine ring (obtained in reactions of 6-aminouracil with oxiranes) are reported. Properties of the foams are investigated, especially their thermal stability. The foams show an improved thermal stability up to 2008C for a long time.
The method of synthesis of polyurethane foams with good thermal stability, containing a 1,3-pyrimidine ring is presented. Oligoetherols obtained in reactions of 6-aminouracil (6-AU) with excess of ethylene carbonate (EC) and propylene carbonate (PC) were used as polyol substrates for synthesis of these foams. Properties of the foams, such as apparent density, water absorption, dimensional stability, thermal stability and compression strength were studied. The obtained foams show a good thermal stability up to 200°C for a long time.
The reactions of 6-aminouracil with ethylene carbonate were investigated. Potassium carbonate or 1,4-diazabicyclo[2.2.2]octane was used as a catalyst. An excess of ethylene carbonate was applied in the syntheses. In this way, polyetherols with 1,3-pyrimidine rings in their structure were prepared. The structure of the products was analyzed with infrared, proton nuclear magnetic resonance, and matrix-assisted laser desorption/ionization time-of-flight techniques. Some physical properties and the thermal stability of the prepared polyetherols were investigated.
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