Effect of oxygen on vinyl acetate polymerization

✍ Scribed by L. B. Levy; L. Hinojosa Jr.

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 568 KB
• Volume: 45
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1992.070450905

✦ Synopsis

Various conflicting reports in the literature regarding the effect of oxygen on the stability of vinyl acetate (VA) toward polymerization led us to reexamine this topic using both isothermal stability tests and quasi-adiabatic calorimetry. Both commercial VA stabilized with 5-20 ppm by weight of hydroquinone (HQ) and purified, unstabilized VA exhibit lower stability to thermally initiated polymerization (at 50-120°C) in the presence of oxygen than in its absence. However, when stabilized with 3-5 ppm of HQ, both air-saturated and oxygen-free VA exhibit adequate thermal stability at normal transport and storage temperatures (25-50°C). Oxygen destabilization of VA is probably caused by the relatively low stability of VA polyperoxide rather than by the oxidation of acetaldehyde impurity to peroxyacetic acid. The length of VA polymerization induction periods is about -0.4 order in oxygen partial pressure.