Results of the reaction of melamine with propylene carbonate in the synthesis of polyetherols with 1,3,5-triazine rings are presented. Optimal conditions of synthesis of the polyetherols are presented and the products characterized by determining selected physical properties and by using spectral methods [H-1-NMR, IR, mass spectroscopy (MS) electrospray ionization (ESI)]. The content of side products was established by GLC. The resulting polyetherols have been found suitable for preparation of polyurethane foams of improved thermal stability. (C) 2003 Wiley Periodicals, Inc.