1976 Volume 49 Issue 3 Pages 169-178
The process for preparing propylene-butadiene alternating copolymer rubber (PBR) was invented by us for first time.The production cost of PBR is now estimated to be quite comparable to that of solution SBR.
As a result of our laboratory test, PBR was found to be a possible tire rubber or general purpose rubber with overall properties intermediate between natural rubber (NR) and SBR.
The most possible advantage of PBR is a better retention of physicals on heat-aging than general purpose rubbers now available such as NR, polycisisoprene (IR), polycisbutadiene (BR) and SBR.A crosslinked structure is formed and hardening-type degradation occurs on heat-aging of SBR and BR.On the other hand, PBR vulcanizate shows breakdown-type degradation on heat-aging as can be seen in the case of NR and IR. However, the degradation rate of PBR is remarkably lower than that of NR and IR under the conditions described in this paper.
