Clay Effect on the Polymerization Behavior and Polymer Molecular Structure

Clay Effect on the Polymerization Behavior and Polymer Molecular Structure 

As a catalyst support material, clays possess unique electronic and structural properties. They may be considered as solid acids, with electrostatic properties that can affect catalytic behavior and, possibly, the microstructure of polymers made with clay-supported catalysts. The layered structure of these aluminosilicates has also been reported to affect polymerization kinetics. Studies in this area have focused on three main effects polymerization activity and stability, polymer molecular weight, and polymer tacticity. 

Marques et al. [76] also showed that when SiMe2(2-Me-Ind)2ZrCl2 was supported on Cloisite 15A, the propylene activity was remarkably decreased. This behavior is in agreement with what has been reported for metallocene catalysts supported on other carriers, such as Si02 and MgCh. 

On the other hand, during butadiene polymerization with cobalt catalysts (CoCl2(PMePli2) 2-MAO and CoCl2(PiPrPh2)2-MAO), Leone et al. [110] showed that supporting on clay had no effect on the polymer microstmcture, either on 1,2-insertion frequency, or on polymer tacticity. 

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