Kinetics and mechanism of initial steps of synthesis of polyetherols from melamine and ethylene carbonate

Abstract

ABSTRACT:The kinetics of initial steps of formation of polyetherols in the reaction between melamine and ethylene carbonate in dimethylsulfoxide in presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) as catalyst was studied. Based upon kinetic studies performed with various concentrations of melamine and catalyst, the rate law was formulated and a mechanism of the reaction was proposed. The activation parameters ⌬G #, ⌬H # , and ⌬S # were obtained from the temperature dependence of kinetics.

Preparation and properties of polyurethane foams from hydroxypropoxy derivatives of urea and isocyanates

“…The foams obtained from product of reaction between BHPU and 14-molar excess of PC (BP14) showed polymerization shrinkage (Table 3, comp. [8][9][10][11][12][13][14]. The best results were obtained when TEA and water content was 4.29 and 2 wt.-%, respectively, while the ratio of OH to NCO in starting mixture was 1:1.75 (Table 3, comp.…”

Oligoetherols and polyurethane foams obtained from metasilicic acid

“…The progress of reaction between semi-product and EC was monitored using barium hydroxide method described in [19]. Acidic number (AN) of obtained oligoetherol was determined by titration with 0.1 M NaOH in the presence of phenolphthalein.…”

Oligoetherols and polyurethane foams obtained from melamine diborate

“…The progress of reaction between MDB and EC was monitored using barium hydroxide method described in [11]. The acid number (AN) of oligoetherols was determined by titration with 0.1 M sodium hydroxide in presence of phenolphthalein.…”