Migration behaviors of antiozonants in binary rubber-based vulcanizates ofNR, SBR, and BR

fluence of rubber composition on migration of N-phenyl-N'-isopropyl-p-pheny lenediamine (IPPD), and N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (HPPD) to the surface in binary rubber-based vulcanizates of natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR) was studie d. Migration experiments were performed at 60 and 80 degrees C for 21 days and outdoors for 4 months. Migration rates of IPPD and HPPD in the vulcaniz ates of SBR/NR and BR/NR blends outdoors increased by decreasing the conten t of NR, and those in the vulcanizates of BR/SBR blends decreased with an i ncrease of the content of BR. Migration behaviors of the antiozonants in th e vulcanizates of SBR/NR and BR/NR blends at 60 and 80 degrees C, on the wh ole, showed trends similar to the outdoor results. Migration rates of the a ntiozonants in the vulcanizates of BR/SBR blends at 60 and 80 degrees C sho wed some differences. Variation of migration behaviors of the antiozonants in the binary rubber-based vulcanizates depending on rubber composition was explained by the interface between dissimilar rubbers and the intermolecul ar interactions between the matrices and the antiozonants. (C) 1999 John Wi ley & Sons, Inc.