Synthesis Of Polyetherols Research Articles

Polyetherols and polyurethane foams with cellulose subunits

ABSTRACT The synthesis of polyetherols based on (hydroxypropyl)cellulose, functionalized with glycidol, and ethylene carbonate was elaborated. All conversions were performed in glycols. The products were characterized by IR, 1H NMR, and MALDI ToF spectroscopy. The polyetherols were then used to obtain rigid polyurethane foams. These foams have apparent density, water uptake, and polymerization shrinkage similar to classic rigid polyurethane foams. The foams showed advantageous thermal resistance in comparison with classic ones. After thermal exposure their compressive strength was improved.

Synthesis of polyetherols with 1,3-pyrimidine ring using 6-aminouracil, ethylene carbonate and propylene oxide

AbstractNew method of synthesis of polyetherols with 1,3-pyrimidine ring by reactions of 6-aminouracil with ethylene carbonate and propylene oxide was described. The structure of products was analyzed using the IR, 1H-NMR and MALDI-TOF spectroscopies. Some physical properties and thermal stability of polyetherols were investigated. Initial tests on the foaming of polyurethanes obtained from the polyetherols were performed. Some properties of the foams such as apparent density, absorption of water, linear dimensions stability, thermal resistance and compression strength were investigated. Obtained foams show an improved thermal stability.

Application of reactive solvents of melamine for synthesis of polyetherols with perhydro-1,3,5-triazine rings

The application of reactive solvents (RSs), namely hydroxymethyl derivatives of acetone for digestion of isocyanuric acid, which is insoluble in most organic solvents except for DMSO, makes the substrate available for further conversions. At this step, the incorporation of perhydro-1,3,5-triazine ring into RS takes place. The obtained solutions were used for synthesis of polyetherols containing perhydro-1,3,5-triazine rings in reaction with oxiranes: ethylene and propylene oxides. The polyetherols were then used to obtain foamed polyurethanes with enhanced thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Synthesis of polyetherols with isocyanuric ring: Kinetics and mechanisms of reactions in the presence of DABCO as catalyst

AbstractTo establish the mechanism of reaction of formation of oligoetherols with perhydro‐1,3,5‐triazine ring, the kinetics of reaction of isocyanuric acid and 1,3,5‐tris(2‐hydroxyetyl) isocyanurate with ethylene carbonate resulting in formation of polyetherols in the presence of diazabicyclo[2.2.2]octane as a catalyst has been investigated. The kinetic and mechanistic studies revealed that the initial step of reaction is zero order related to ethylene carbonate and the reaction is inhibited by imide groups of isocyanuric acid. The mechanism of reaction was confirmed by spectroscopic and electrochemical methods. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 550–561, 2010

Synthesis of polyetherols with isocyanuric ring. Kinetics and mechanisms of reactions, part 2: Consecutive reaction of ethylene carbonate with isocyanuric acid

AbstractThe kinetics and mechanism of the reaction between isocyanuric acid and ethylene carbonate was studied. The multistep reaction in the presence of potassium carbonate as catalyst leads to polyetherols. The imide and hydroxyl groups of intermediates react with ethylene carbonate by slightly different mechanism and kinetics. The rate constants for these elementary processes were established, and based on these experimental data the mechanism of reaction was proposed. Using the isocyanuric acid and 1,3,5‐tris(2‐hydroxyethyl)isocyanurate, it has been found that the reaction of ethylene carbonate with intermediates occurs via a mixed mechanism. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 523–531, 2009

Synthesis of polyetherols with isocyanuric ring. Kinetics and mechanisms of reactions, part 1: Reaction between isocyanuric acid and ethylene carbonate

AbstractThe reaction between isocyanuric acid and ethylene carbonate results in the formation of polyetherols. The kinetic and mechanistic studies revealed that the initial step of the reaction is zero order related to ethylene carbonate. The rate‐limiting step is the decomposition of an intermediating dianion of ethylene dicarbonate into ethane‐1,2‐diolate dianion and carbon dioxide. Imide groups of isocyanuric acid inhibit the reaction. The mechanism of reaction was confirmed by spectroscopic methods. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 512–522, 2009

Hydroxyalkylation of barbituric acid. II. Synthesis of polyetherols with pyrimidine ring

AbstractThe route of synthesis of new polyetherols with pyrimidine ring from barbituric acid (BA) was presented. The polyetherols were obtained in two steps: synthesis of hydroxymethyl derivative of BA followed by reaction of the latter with neat ethylene or propylene oxides. Physical properties of the products and preliminary application for fabrication of thermal stability polyurethane foams were determined. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Synthesis of polyetherols with purine ring. Kinetics and mechanisms of reactions, part 1: Reaction of hydroxymethyl derivatives of uric acid with oxiranes

AbstractThe kinetics and mechanisms of the initial steps of formation of polyetherols from hydroxymethyl derivatives of uric acid and oxiranes were studied. It has been found that initial steps of the reaction of polyetherol formation occur without a catalyst. The NH groups, which are formed upon release of formaldehyde from N‐ and O‐hydroxymethyl derivatives of uric acid, take part in the reaction. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 464–471, 2005

Synthesis of polyetherols with purine ring. Kinetics and mechanisms of reactions, part 2: Reactions in the presence of triethylamine

AbstractThe kinetics and mechanism of reaction between hydroxymethyl derivatives of uric acid and oxiranes in the presence of triethylamine as catalyst was studied. The formation of polyetherols was inhibited in initial steps of the reaction. Two different mechanisms were established for the reactions in which intermediates contained O‐hydroxymethyl and O‐(2‐hydroxyethyl) groups. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 472–482, 2005

Synthesis of polyetherols from melamine and propylene carbonate. II

AbstractResults 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 [1H‐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. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 104–115, 2003

Synthesis of polyetherols from melamine and ethylene carbonate

AbstractAttempts to synthesize s‐triazine ring containing polyetherols from melamine and ethylene carbonate are described. The conditions of synthesis providing optimal yields of the polyetherols were 165°C, melamine to ethylene carbonate molar ratio 1 : 9 to 1 : 18, and 4 g of potassium carbonate or diazabicyclo[2.2.2]octane catalyst per mole of melamine. The structure of the products was established by 1H‐NMR and IR spectroscopy. The kind and amount of side products [mostly poly(ethylene glycols)] was determined by GLC. The polyetherols have been found useful in the synthesis of polyurethanes of improved thermal stability. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1776–1784, 2001

Reactions of hydroxymethyl derivatives of uric acid with oxiranes. I. Synthesis of polyetherols with purine rings

Reactions of hydroxymethyl derivatives of uric acid with oxiranes. I. Synthesis of polyetherols with purine rings

Reactions of trithiocyanuric acid with oxiranes. I. synthesis of polyetherols

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 hydroxymethyl derivatives of uric acid with oxiranes. I. Synthesis of polyetherols with purine rings

Preliminary results on the utilization of uric acid in the synthesis of a new group of polyetherols with purine rings are presented. The polyetherols were prepared in a two-stage process. First, hydroxymethyl derivatives of uric acid were obtained from an uric acid and formaldehyde solution. This intermediate was then reacted with ethylene oxide or propylene oxide without any additional solvent. The structure of the intermediates and polyetherols and some of their physical properties were determined, and the possibilities of application of the polyetherols in manufacturing thermostable polyurethane foams were tested. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2667–2677, 2000

Synthesis of polyetherols with s‐triazine ring catalyzed by tetrabutylammonium hydroxide

AbstractSome results of invesgitations of the synthesis of polytherols with s‐triazine ring by reaction of melamine with oxiranes using tetrabutylammonium hydroxide as catalyst are presented. The physico‐chemical properties of the products have been examined. By means of analytical methods, infrared and 1H‐NMR spectroscopy the structure of the compounds has been determined.