Atactic polypropene was synthsised with homogeneous catalytic systems of varios titanium compounds activated by methylaluminoxane(MAO).The titanium ligands affect both catalytic activity and stereoregularity of polypropene obtained.For novel η 5 cyclopentadienyltri n propyloxy titanium CpTi(O n Pr) 3 /MAO catalytic system

the influencing factors of polymerization temperature

Al/Ti molar ratio and propene pressure on propene polymerization have been studied.The catalytic activity at polymerization temperature 40℃ and Al/Ti molar ratio 200 was 220kgPP/molTi-h.The kinetics of early state propene polymerization with CpTi(O-n-Pr)3/MAO has been inverstigated.The polymer yield increases almost linearly with increasing the titamium or monomer concentration.The apparent rate of polymerization (Rp)versus titanium and monomer concentration appears the first order reaction rule

and the apparent rate constant(Kp)is 2.92×105mol·L-1·h-1 at 40℃.The calculated polymerization activation energy (△E)is 7.88×103J·mol-1

while the impact fractor(A) is 1.41×104mol·L-1·h-1. After boiling heptane extraction of the polypropene for 8h.The soluble fraction with more than 95% by weight was isolated and characterized as atactic polypropene by 13CNMR

WAXD and FTIR.The molecular weight (Mw)and its distribution (Mw/Mn) determined by GPC were 8.0～10.0×104 and 2.0 respectively.