Are Vazo™ free radical sources toxic?
Vazo™ free radical sources exhibit low-to-moderate toxicity. However, tetramethylsuccinonitrile (TMSN), a byproduct of Vazo™ 64, is highly toxic. Vazo™ 67 is a safer alternative.
Is it important to store Vazo™ initiators at or below the temperature recommended by Chemours?
Yes, storing Vazo™ initiators at or below the recommended temperature is extremely important. These materials naturally decompose, and the rate of decomposition is dependent on the temperature at which they are stored. Storing at or below the recommended temperature ensures product quality through the duration of the stated shelf life. Storing some of these initiators above recommended storage temperature could result in self-accelerated decomposition and potential fires.
What are the recommended storage temperatures?
To ensure product quality through the duration of the stated shelf life, Chemours strongly recommends storing all Vazo™ initiators at or below 8 °C (46 °F). There is no absolute minimum temperature at which Vazo™ initiators can be stored.
In order to ensure safety, it's critically important that these materials be stored at temperatures not exceeding the following limits:
- Vazo™ 52: 10 °C (50 °F)
- Vazo™ 64 and Vazo™ 67: 24 °C (75 °F)
- Vazo™ 88: 35 °C (95 °F)
- Vazo™ 56 WSP, Vazo™ 56 WSW, and Vazo™ 68 WSP: 40 °C (104 °F)
Is there an explosion hazard with airborne dust from Vazo™ free radical initiators?
Yes, like many organic chemicals, airborne dust will form explosive mixtures in air.
In emulsion polymerization processes, I normally use a persulfate. Under what circumstances might water-soluble Vazo™ initiators be a better choice?
Among other advantages, water-soluble grades of Vazo™ (56 WSP, 56 WSW, and 68 WSP) offer narrow molecular weight distribution and minimal branching. They are also sulfur free. Although used predominantly in an emulsion polymerization mechanism, water-soluble grades of Vazo™ can also be used in solution polymerization.