Calculations in PU Software. Definitions (2)
NCO-Side (2)
Polyol-Side (2)
Parts (2)
Parts by Weight (2)
Parts by 100 (2)
Parts by 100 Polyols (2)
Side Composition (2)
Products Properties (2)
Functionality (2)
Equivalent Weight of a Polyol (2)
Equivalent Weight of a Polyol Blend (3)
Equivalent Weight of an Isocyanate (3)
Equivalent Weight of an Isocyanate Blend (3)
Acid Number (3)
Hydroxyl Number (OH Number) (3)
Equivalent Number (3)
Molecular Weight (3)
Number of Moles (3)
Real Functionality (3)
Calculations for a Formulations (4)
Average Equivalent Weights [g/mol] (4)
Enthalpy [cal/g] (4)
Average Functionality (4)
Average Real Functionality (4)
Total Equivalent Numbers [mol] (4)
Volume Gas [mol/kg] (4)
Converted at Gel point [%] (5)
Isocyanate index (5)
OH Links (5)
Urethane-Urea Linkages (5)
Molecular weight per CrossLink [g/mol] (5)
Average Second Moment Functionality (6)
Average CrossLink Functionality (6)
Blowing Index [mol/kg] (6)
Definitions
The following definitions apply:
NCO-Side
The isocyanate-containing blend (Isocyanates, other NCO additives…). Called A-Side in US.
Polyol-Side
The polyol-containing blend, (polyols, chain extenders, cross-linker, water, catalysts and surfactants). Called B-Side in US.
Parts
Independent Component Weight Quantity
Parts by Weight
Component Weight Quantity over Total 100 w/o Physical Blowing Agent. Parts by 100
Component Weight Quantity over Total 100
Parts by 100 Polyols
Component Weight Quantity over Total Polyols 100
Side Composition
Component Weight Quantity over its Side 100
Products Properties
Functionality
The functionality of a Polyol-side foam ingredient is the number of isocyanate reactive sites on a molecule. For polyols, an average
functionality is generally used:
polyol moles / total OH moles total ity Functional Average =
Equivalent Weight of a Polyol
Classically defined as the molecular weight of a polyol divided by its functionality. Functionality of a polyol is complex because of the presence of monols from propylene oxide isomerization and diols (derived from water). In practice, the equivalent weight is calculated from the analyzed hydroxyl (OH) number. The equivalent weight is necessary for isocyanate requirement calculations and is derived from the following expression:
Number OH / 1000 x 56.1 Polyol a of Weight Equivalent =
