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

Abstract

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.

Polyurethane foams with the contribution of products of hydroxyalkylation of N,N′‐bis(2‐hydroxyalkyl)oxamides with alkylene carbonates—obtaining and properties

“…14,15 It should be emphasized that the polyurethane foams obtained with contribution of hydroxyalkyl urea derivatives obtained with N,N 0 -bis(2-hydroxyalkyl)ureas and ACs have improved properties compared to the foams obtained with contribution of urea and ACs reaction products. 5,11 A similar dependence was expected in the case of hydroxyalkyl derivatives OD and BHAOD.…”

“…Drying time of the foams obtained from polyols with BHEOD and EC was usually short; the foams were almost dry on completion of the growth (Table III), and in the case of foams obtained with hydroxypropoxy derivatives of OD-after 3-27 s (Table III, comp. [5][6][7][8][9][10][11][12][13].…”

“…Furthermore, there was compared properties of polyurethane foams obtained with contribution of hydroxyalkyl OD derivatives with the properties foams obtained with contribution of hydroxyalkyl derivatives of urea. 6,11 The experimental conditions, hydroxyl number, and functionality of the polyols are similar. The water uptake is smaller and dimension stability is higher in the foams obtained with the contribution of hydroxyalkoxy derivatives of OD than in foams obtained with contribution of hydroxyalkoxylated derivatives of urea.…”

“…8 In particular, the foams obtained with contribution of hydroxypropoxy derivatives of parabanic acid and oxamic acid are distinguished by good physical properties as well as the increased thermal stability. 5,6,[9][10][11] In the structure of parabanic acid one can also distinguish a structural fragment of oxamide (OD); the reaction products of OD and N,N 0 -bis(2-hydroxyalkyl)oxamides (BHAOD) with ACs are also characterized by the increased thermal stability. [12][13][14] Use of the hydroxyalkylation products of OD with ACs as polyol components resulted in obtaining rigid foamed polyurethane plastics, 14,15 of the properties similar to the foams obtained with the contribution of hydroxyalkyl derivatives of parabanic acid and oxamic acid.…”

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

“…Rigid polyurethane foams obtained with their contribution are characterized by a slight water uptake, good stability of dimensions, enhanced thermal stability and good compression strength [7]. Similarly, reaction products of oxamic acid and carbamide with ACs can be used for obtaining thermally stable polyurethane foams [5,6,8,9].…”