Product Grades

For Solvent Systems

Chemours offers four commercial grades: Vazo™ 52, 64, 67, and 88. The grade number is the Celsius temperature at which the half-life in solution is 10 hours. These grades are:

Delivered in solid white "noodle" form

Soluble in a wide variety of solvents (aromatic hydrocarbons and other functional organic compounds)

Slightly soluble in aliphatic hydrocarbons

Insoluble in water






Grade Selection Guide

Selecting a Grade of Vazo™

Temperature Range

The most important criterion for choosing the correct grade of Vazo™ free radical sources is the temperature at which the reaction is to be run. Vazo™ FRSs are generally used within a range of 10 to 30°C (18 to 54°F) above the temperature corresponding to the grade number. This range is a rough guideline only. For instance, Vazo™ 64 has been used at 125°C (257°F), where the half-life is less than 1 minute.


Half-life (t1/2), expressed in minutes as a function of temperature, varies for each grade of Vazo™ according to the formulae below. (T = temperature in °K.)

Vazo™ 52: log (t1/2) = 6767 (1/T) - 18.037 (in toluene)

Vazo™ 64: log (t1/2) = 7142 (1/T) - 18.355 (in toluene)

Vazo™ 67: log (t1/2) = 7492 (1/T) - 19.215 (in 1,3,5-trimethylbenzene)

Vazo™ 88: log (t1/2) = 7660 (1/T) - 18.39


Another factor in choosing a particular grade is solubility. The other grades are essentially insoluble in water, sparingly soluble in aliphatic hydrocarbons, and soluble in functionalized organic compounds and aromatic hydrocarbons. Vazo™ 67 is significantly more soluble in organic solvents and monomers than the other grades. Caution must be used in the handling of highly concentrated solutions to avoid a self-accelerating decomposition.