Chain scission of butyl rubber by nitrogen dioxide in absence and presence of air

The chain scission reaction suffered by butyl rubber due to NO₂ (0.01-1 mm Hg) has been studied in the presence and absence of air. It has also been studied as a function of temperature (25–65°C) at constant NO₂ pressure, again in absence and presence of 1 atm of air. Reaction mechanisms which are in good agreement with the experimental results have been formulated. The synergistic action of O₂ and NO₂ has been pointed out.