Control of Ziegler–Natta catalyst activity by the structural design of alkoxysilane-based external donors

Abstract

Herein, the evaluation of four commercial alkoxysilanes and two laboratory synthesized novel diethoxysilacycloalkanes as external donors towards propylene polymerization has been done.

Mechanistic Study on Effect of Electron Donors in Propylene Polymerization Using the Ziegler–Natta Catalyst

“…Khatri et al carried out a theoretical study of the complexes formed by external donors and triethylaluminium (TEA). 44 The existence of weak interactions between external donors and TEA through charge transfer has been proved by the DFT and NBO studies. The AlR 2 Cl molecule is the activation reagent or the product generated from the activation event along with the formation of the Ti active site.…”

“…Also, researchers have considered the influence that the cocatalyst alkylaluminum may have had on the external donors during the polymerization. Khatri et al carried out a theoretical study of the complexes formed by external donors and triethylaluminium (TEA) . The existence of weak interactions between external donors and TEA through charge transfer has been proved by the DFT and NBO studies.…”

Century Impact of Macromolecules for Advances of Sensing Sciences

“…Another, breakthrough in the preparation of polymer appears with the discovery of Karl Ziegler and Giulio Natta in the form of hybrid catalyst from the salt of transition and alkali earth metals, which were called “Zigler Natta Catalysts”. This catalyst was prominently used in the polymerization of olefines like polypropylene with stereo structure regularizations and effective methodology as well as yields [ 9 ]. In the progress of macromolecules, another turn took place with the discovery of electrical conductivity after doping of halogen i.e.…”

Performance of post phthalate Ziegler Natta catalysts with activity limiting agents for propylene gas phase polymerization

“…Several other patents disclose novel mixtures of external donors and processes where an ALA is used, including in the production of impact propylene copolymers [6] , in the production of high melt flow propylene polymers [7] , in the production of ethylene based polymers [8] , the discontinuous addition of thermal runaway control agents in commercial production of polypropylene [9] , the use of monoether compounds as ALAs [10] , utilizing fluorinated fatty acids as ALAs [11] , and an improved multi-zone olefins polymerization process operating in deep condensed modes employing several thermal runaway control agents [12] .…”