The advances of the external electron donor technology in Ziegler-Natta catalyst system for propylene polymerization

including the types

the effects on the active center and the action mechanism

were reviewed. This paper especially emphasized the influences of structure effect and electron effect of donors on polypropylene catalyst system

and pointed out the typical structure characteristic of excellent external electron donors

which are silane compounds with both hydrocarbon substituent of big steric hindrance and alkoxy substituent of small steric hindrance. Besides

the role of external electron donor in propylene copolymerization and mulriple external electron donor technology

and the development trend of the external electron donor technology were introduced.