Iwona Zarzyka-Niemiec

Obtaining of polyurethane foams with contribution of hydroxyalkylation products of oxalamide with alkylene carbonates and their properties

Abstract Reaction products of Oxalamide (OD) with a 8- and 12-molar excess of ethylene carbonate (EC) and propylene carbonate (PC), characterized by an enhanced thermal stability due to the presence of Oxalamide arrangement, were used as polyol components for obtaining foamed polyurethane plastics. As an isocyanate agent diphenylmethane-4,4’-diisocyanate was used. The obtained new foamed polyurethane plastics are characterized by a slight water uptake, good stability of dimensions and an enhanced thermal stability.

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

Abstract The products of hydroxyalkylation of N,N’-bis(2-hydroxypropyl)urea (BHPU) with large molar excess of propylene carbonate (PC) posses enhanced thermal stability. These products and 4,4’-diphenylmethane diisocyanate were used as substrates for obtaining rigid polyurethane foams, which had high thermal stability and low water uptake.

Polyhydroxyalkylation of urea with ethylene carbonate and application of obtained products as components of polyurethane foams

Abstract The reaction between urea and ethylene carbonate occur with partial release of CO2 and partial incorporation of carbonate groups into products. The carbonate groups were found to be attached both to nitrogen of urea and to oxyethylene chain. The most effective catalyst of the synthesis was potassium carbonate. The hydroxyethyl and hydroxyethoxy groups of urea derivatives undergo partial dimerization to form carbamate groups in the products. The products of reaction between urea and ethylene carbonate have good thermal stability, they start to decompose at 200°C. The obtained products can be used as polyol components for polyurethane foams. Polyurethane foams obtained from hydroxyethoxy derivatives of urea (EC8) are rigid products of low water uptake, good stability of dimensions, low mass loss on 30 days heating at 150°C, enhanced thermal stability and good compressive strength.

Comparison Of Reaction Pathway And Product Analysis For Hydroxyalkylation Of Parabanic Acid With Oxiranes And Alkylene Carbonates

Abstract Reactions of parabanic acid (PA) with ethylene and propylene oxides and carbonates lead to oligomeric products with hydroxyalkyl groups in both cases. The parabanic acid ring undergoes scissions during reactions depending on kind of reagent and reaction conditions. In some cases the trioxoimidazolidine ring remains untouched. Using the MALDI ToF technique the product analysis was performed. The by-products were determined quantitatively by GC. The thermostability of oligomeric products was also determined.