Reactions of N,N^′-bis(2-hydroxyethyl)oxalamide with Ethylene Carbonate and Use of the Obtained Products as Components of Polyurethanes Foams

Table 4

Parameters of foaming process.

Initial molar ratio BHEOA :  EC in polyol		Composition (g/100 g of tetraol)				Foaming process			Properties of foams just prepared
	Composition	isocyanate^a	water	catalyst^b	molar ratio OH : NCO	time (s)
	No.					creaming^c	expanding^d	drying^e
1 : 6	1.	200	2	0.50	1 : 1.57	36.5	18	0	rigid
1 : 10	2.	212	2	0.50	1 : 2.31	17	7	0	rigid

a: 4.4^′-diphenylmethane diisocyanate, b: triethyloamine,
c: Time of Creaming: the time elapsed from the moment of mixing to the start of volume expansion.
d: Time of Expanding: the time from the start of expansion to the moment of reaching the sample final volume.
e: Time of Drying: the time from reaching by the sample its final volume to the moment of loosing its surface adhesion to powdered substances.