Addition of a second alcohol in magnesium ethoxidesynthesis as a way to vary the pore architecture ofZiegler-Natta catalysts

In Ziegler-Natta olefn polymerization, the pore architecture of catalysts plays a crucial role in catalytic performances and polymer properties. While the type of preparation routes (such as chemical reaction andsolution precipitation) greatly affects the catalyst pore architecture as a result of different solidifcation mechanisms,the modifcation of the pore architecture within a given route has been hardly achieved. In this study, we proposea simple way to vary the pore architecture of Mg(OEt)2-based Ziegler-Natta catalysts by the addition of a secondalcohol. It was found that the addition of a second alcohol during Mg(OEt)2 synthesis affected not only themorphology of Mg(OEt)2 macroparticles but also the shape of building units. The degree of alternation was foundto be sensitive to the molecular structure of a second alcohol. Noticeable influences were observed in the case ofbranched alcohols, where the transformation of plate-like building units to cylindrical ones led to the generation oftotally different pore size distributions of resultant catalysts. Polyolefns J (2015) 2: 65-71

Keywords:

Ziegler-Natta catalysts , pore architecture , magnesium alkoxide