Table 1.

Formulation of the polyurethane (PU) foam.

Materials		Formulation (php a)
Polyol		100
Polymeric diphenylmethane diisocyanate	NCO index	120
Chain extender	1, 3-Propanediol	10
Silicon surfactant	TEGOSTAB B-4862	2
Catalyst	DMCHA	0.2
	DBTDL	0.1
Blowing agent	Water	3

^a php: parts per hundred of polyol by weight.