Correlation between migration behaviors of antiozonants and temperature

Migration behaviors of antiozonants depending on temperature were studied using a carbon black‐filled NR vulcanizate containing N ‐phenyl‐ N ′‐isopropyl‐ p ‐phenylenediamine (IPPD) and N ‐phenyl‐ N ′‐(1,3‐dimethylbutyl)‐ p ‐phenylenediamine (HPPD) as antiozonants. The experimental temperatures were 100, 90, 80, and 70°C. Migration rates of them increased steeply by increasing the temperature. The correlation between the migration rates and the temperature was investigated using the half (t 1/2 ) ‐ and quarter (t 1/4 ) ‐lifetimes of the migrants remaining in the vulcanizate after the migration. The plot of log t versus 1/T was well fitted by the linear equation: The correlation coefficients were higher than 0.995. It was found that the migration behavior and temperature had a correlation of log t = b/T + c, where t and T are the migration time and temperature, b is E a /R, and c is the constant. The activation energies for the migration were 36.48 and 37.93 kJ/mol for IPPD and HPPD, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1566–1570, 2001