Cure Terms Glossary

Percentage Isocyanate

The percentage isocyanate is the percentage by weight of isocyanate groups in the substance. It applies to all available isocyanate groups whatever the size of the molecule to which they are attached. It is related to the equivalent weight in isocyanate. Since the molar mass of the isocyanate (NCO) group is 42.02 in atomic mass units, then the percentage weight of the NCO groups in the substance is given by,