Multi-Alkenylsilsesquioxanes as Comonomers and Active Species Modifiers of Metallocene Catalyst in Copolymerization with Ethylene.

Paweł Groch,Krystyna Czaja,Katarzyna Dziubek,Katarzyna Mituła,Beata Dudziec

doi:10.3390/polym10020223

Paweł Groch, Krystyna Czaja + Show 3 more

Open Access

https://doi.org/10.3390/polym10020223

Copy DOI

Journal: Polymers	Publication Date: Feb 24, 2018
Citations: 9	License type: CC BY 4.0

Affiliation: Opole University, Adam Mickiewicz University in Poznań

Abstract

The copolymers of ethylene (E) with open-caged iso-butyl-substituted tri-alkenyl-silsesquioxanes (POSS-6-3 and POSS-10-3) and phenyl-substituted tetra-alkenyl-silsesquioxane (POSS-10-4) were synthesized by copolymerization over the ansa-metallocene catalyst. The influence of the kind of silsesquioxane and of the copolymerization conditions on the reaction performance and on the properties of the copolymers was studied. In the case of copolymerization of E/POSS-6-3, the positive comonomer effect was observed, which was associated with the influence of POSS-6-3 on transformation of the bimetallic ion pair to the active catalytic species. Functionality of silsesquioxanes and polymerization parameters affected the polyhedral oligomeric silsesquioxanes (POSS) contents in the copolymers which varied in the range of 1.33–7.43 wt %. Tri-alkenyl-silsesquioxanes were incorporated into the polymer chain as pendant groups while the tetra-alkenyl-silsesquioxane derivative could act as a cross-linking agent which was proved by the changes in the contents of unsaturated end groups, by the glass transition temperature values, and by the gel contents (up to 81.3% for E/POSS-10-4). Incorporation of multi-alkenyl-POSS into the polymer chain affected also the melting and crystallization behaviors.

Highlights

One of many advantages of polyhedral oligomeric silsesquioxanes (POSS) is their structural diversity
The hybrid copolymers of ethylene with open-caged iso-butyl-substituted tri-alkenyl-silsesquioxanes (POSS-6-3 and POSS-10-3) and phenyl-substituted tetra-alkenyl-silsesquioxane (POSS-10-4) were for the first time successfully synthesized by coordinative copolymerization with the use of the metallocene catalytic system (rac-Et(Ind)2 ZrCl2 /MMAO)
The performance of copolymerization was found to be significantly affected by the kind and concentration of the silsesquioxane comonomer in the feed as well as by the ethylene pressure and reaction time

Summary

Introduction

One of many advantages of polyhedral oligomeric silsesquioxanes (POSS) is their structural diversity. The POSS derivatives may be classified into three groups: mono-functional POSS, di-functional POSS, and multi-functional POSS, depending on the number of the reactive functional substituents. The copolymers with the POSS cages as pendant side groups or end groups of the polymer chains are prepared when mono-functional POSS are used [3,4,5,6,7,8,9]. Depending on the types of reactive substituents, they have been successfully incorporated into such macromolecules as polyimide [9,10,11], polysiloxane [12], polyamide [13], polyurethane [14], polysulfone [15], vinylidene-arylene copolymer [16], and polyethylene [17], via the Polymers 2018, 10, 223; doi:10.3390/polym10020223 www.mdpi.com/journal/polymers

Objectives

Methods

Results

Conclusion