A Brief Review of the Cocatalysts Types and their Performance in (Co)Polymerization Processes of Olefins: From Synthesis to Industrial Application

• Published in: Baspārish (Tihrān. Online) Vol. 12; no. 2; pp. 27 - 35
• Main Authors: maryam masoori, Reza Rashedi, Abdolhannan Sepahi, Mohammad Hossein Jandaghian, Ehsan Nikzinat, Saeed Houshmand moayed
• Format: Journal Article
• Language: Persian
• Published: Iran Polymer & Petrochemical Institute 01-08-2022
• Subjects: aluminum alkyl; catalyst; cocatalyst; polymer properties; polymerization
• ISSN: 2252-0449; 2538-5445
• DOI: 10.22063/basparesh.2021.2942.1562

In the past, most researchers believed that cocatalyst is a passive component that only has the task of "removing impurities" and "alkylating" the active centers of catalyst at the beginning of the polymerization and does not play a specific role in the polymerization. Today, it has been proven that this belief is incorrect, because the use of various cocatalysts leads to the induction of various properties in the final polymer, which is inconsistent with this view. Cocatalyst (negative ion) and active catalytic centers (positive ion) form "ion pairs" that govern the microstructure and arrangement of monomers in polymer chains during polymerization reaction. One of the important factors in the polymerization of ethylene α-olefin is the choice of aluminum alkyl to control the activity and properties of the polymer. In this article, the importance of the role of cocatalyst in the polymerization of Ziegler-Natta, metallocene, and hybrid catalysts, its effect on the catalyst behavior, distribution of active catalytic centers, catalyst activity and properties of polymer products such as molecular weight, molecular weight distribution, wax percentage, comonomer incorporation and physical-mechanical properties such as strength and impact resistance were reviewed. The results showed that each cocatalyst, due to its nature and chemical structure, causes alkylation of active catalytic centers and therefore produces polymers with various properties. Also, the use of a combination of different types of cocatalysts can induce different properties than each of the cocatalysts alone in the polymerization process.