Polyether Polyols for Rigid Polyurethane Foams


Polyether polyols for rigid polyurethane (PU) foams are low molecular weight (MW) adducts of propylene oxide (PO) [sometimes together with ethylene oxide (EO)] to polyols or to polyamines having 2-3 amino groups/mol, the chain derived from one hydroxyl group being very short. 




Rigid foam.jpg


The characteristics of some polyether polyols for rigid PU foams

 

Characteristic

Unit

Type I

Type II

Hydroxyl number

mg KOH/g

450-490

500-550

Viscosity, 25 °C

MPa-s.

4500-8000

20000-30000

Acid number

mg KOH/g

max. 0.1

max. 0.1

Water content

%

max. 0.1

max. 0.1

Density, 25 °C

g/ml

1.08-1.1

1.09-1.15

Na and K

ppm

max.50

max.50