3.4. Thermal aging behavior of NR–PBR/RR blend system
The aging characteristics of NR–PBR/RR vulcanizates should be
given proper attention because RR itself is a degraded mass. Thus,
accelerated aging tests were performed for NR–PBR/RR vulcanizates. Percent retention of 200% moduli is shown in Fig. 7. In all
the cases, it is observed that percent retention of 200% moduli increases with the increasing RR content and with the progress of
aging. This may be due to residual crosslinking during progress