Polymerisation mechanisms homogeneous metallocene

In the case of olefin polymerisation with homogeneous Ziegler-Natta catalysts, especially with single-site (metallocene) catalysts, the kinetic analysis may become simpler than in the case of polymerisation with heterogeneous catalysts, and in some instances can serve as a very useful tool for uncovering the true polymerisation mechanism [30,243],... 

A detailed molecular mechanics analysis of model catalytic sites has rationalised these observed behaviours for homogeneous propylene isospecific polymerisation catalysts based on bridged rac.-metallocene [357], It is interesting that, in contrast to the discussed case of enantioselectivity of the models for the primary insertion of propylene, the enantioselectivity of the models for the secondary insertion of propylene is due to direct interactions of the... 

At the end of considerations of the stereoregulation mechanism in the isospecific polymerisation of a-olefins with homogeneous catalysts obtained from chiral stereorigid metallocenes of class III with C2 molecular symmetry, let us address isospecific propylene polymerisation catalysts, which are methy-laluminoxane-activated non-bridged metallocenes (Table 3.2). 

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