Correlation between migration behaviors of antiozonants and temperature

Migration behaviors of antiozonants depending on temperature were studied u sing a carbon black-filled NR vulcanizate containing N-phenyl-N ' -isopropy l-p-phenylenediamine (IPPD) and N-phenyl-N '-(1,3-dimethylbutyl)-p-phenylen ediamine (HPPD) as antiozonants. The experimental temperatures were 100, 90 , 80, and 70 degreesC, Migration rates of them increased steeply by increas ing the temperature. The correlation between the migration rates and the te mperature was investigated using the half (t(1/2))- and quarter (t(1/4))-li fetimes of the migrants remaining in the vulcanizate after the migration. T he plot of log t versus 1/T was well fitted by the linear equation: The cor relation coefficients were higher than 0.995. It was found that the migrati on behavior and temperature had a correlation of log t = b/T + c, where t a nd T are the migration time and temperature, b is E-alpha/R, and c is the c onstant. The activation energies for the migration were 36.48 and 37.93 kJ/ mol for IPPD and HPPD, respectively. (C) 2001 John Wiley & Sons, Inc.