GUIDE TO EPOXY CALCULATIONS

To calculate the desired stöchiometric quantity of amine in weight parts per 100 gram epoxy resin the following formula can be used:

Equivalent weight amine           x 100
Equivalent weight epoxy resin

To which eq.weight amine is:  molecular weight amine                                                                                    Number of active hydrogen atoms of the amine       

and

Eq.weight epoxy is: amount of grams of resin that contains one molecule of an epoxy group.

The epoxy equivalent weight can be calculated as follows:

Molecular weight epoxy resin
Number of epoxy groups

Another way is to calculate with epoxy number and amine number that can be defined as follows:
  Epoxy number = 100 / epoxy eq.weight
  Amine number = 100 / amine eq.weight
  To calculate epoxy groups per molecule : (Epoxy number x mol.weight) / 100
  To calculate OH groups per molecule : (OH number x mol.weight) / 100
  To calculate mol.weight : (100 x epoxy groups per molecule)  / epoxy number
  To calculate mol.weight : epoxy eq.weight x epoxy groups per molecule