Influence of Precomplexing Reaction for N Catalyst on Behavior of Propylene Polymerization

Behavior of propylene slurry polymerization was investigated at 15 ℃ , 0.12 MPa using N-catalyst, precomplexed with AlEt3 (co-catalyst) and CHMMS (ex ternal electron-donor). Precomplexing had great influence on behavior of polyme r ization of N catalyst. With complete precomplexing reaction for the catalyst , despite any mass fraction variation of Ti in catalyst, the kinetic curve and pol ymerization activity of catalyst basically kept same. With partial and/or half precomplexing reaction for catalyst, the kinetic curve and polymerization activ i ty of catalyst with higher mass fraction of Ti kept same as that with complete p recomplexing. However, catalyst with lower mass fraction of Ti showed obvious d e caying kinetic behavior. Without precomplexing reaction for catalyst, decaying behavior was showed obviously. AlEt3 had great effect on initiating and maint aining a ctivity center number during polymerization without precomplexing reaction. The conclusion will be useful to industrial application of N catalyst.