Calculation of Anhydride-type Curing Agent Dosage

When using anhydride curing agents, we can generally calculate the dosage using the following formula:

Where "c" is the correction factor:

• For general anhydrides, c=0.85−0.9c = 0.85 - 0.9；
• For using tertiary amine curing agents, c=1；
• For using chlorinated anhydrides, c=0.6c = 0.6.

Example:

If the relative molecular mass of Methyl Tetrahydrophthalic Anhydride (MTHPA) is 168, and it contains one anhydride group,

To calculate the amount of anhydride needed for curing E-51 epoxy resin, the dosage calculation is:

This means that approximately 77 grams of MTHPA are needed to cure 100 grams of E-51 epoxy resin.

Precautions

Anhydride-type curing agents are quite corrosive. Proper and careful handling is required. Wear gloves, masks, and other protective gear to avoid inhalation and contact. Clean thoroughly after handling.