control of hydrogen response for polypropylene obtained by ziegler-natta catalyst: effect of external donor

An insight into the effect of different external donor structures, comprised of diisopropyl dimethoxy propane (dmp) and 2,2-diisopropyl succinate (ips), bis benzyloxy dimethy silan (bds) on the performance of mgcl2 supported ziegler-natta catalyst in propylene polymerization is developed and the resules compared with conventional alkoxysilane (c) external donor. using dmp as external donor showed higher activity than ips and bds. on the other hand, dmp as external donor is more efficient in converting low molar mass centers to higher ones. meanwhile, it showes higher hydrogen response in comparison to alkoxysilane (c). a promising feature of these data is  providing a guideline to study the effect of diether and succinate compounds as external donor.