Comparative study of copolymerization and terpolymerization of ethylene/propylene/diene monomers using metallocene catalyst

Abstract

Ind) 2 ZrCl 2 catalyst was synthesized and used for copolymerization of ethylene and propylene (EPR) and terpolymerization of ethylene propylene and 5-ethyldiene-2-norbornene (ENB). Methylaluminoxane (MAO) was used as cocatalyst. The activity of the catalyst was higher in copolymerization of ethylene and propylene (EPR) rather than in terpolymerization of ethylene, propylene and diene monomers. The effects of [Al] : [Zr] molar ratio, polymerization temperature, pressure ratio of ethylene/propylene and the ENB concentration on the terpolymerization behavior were studied. The highest productivity of the catalyst was obtained at 60 C, [Al] : [Zr] molar ratios of 750 : 1 and 500 : 1 for copolymerization and terpolymerization, respectively. Increasing the molar ratio of [Al] : [Zr] up to 500 : 1 increased the ethylene and ENB contents of the terpolymers, while beyond this ratio the productivity of the cata-lyst dropped, leading to lower ethylene and ENB contents. Terpolymerization was carried out batchwise at temperatures from 40 to 70 C. Rate time profiles of the polymerization were a decay type for both copolymerization and terpolymerization. Glass transition temperatures (T g ) of the obtained terpolymers were between À64 and À52 C. Glass transition temperatures of both copolymers and terpolymers were decreased with increased ethylene content of the polymers. Dynamic mechanical and rheological properties of the obtained polymers were studied. A compounded EPDM showed good thermal stability with time.

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

“…1,2 The existence of ring strain in the structure of norbornene (NBE) and its derivatives makes them facile polymerizable, thus NBE has become one of the most active participants in ethylene/cyclo-olen copolymerization. 7,[9][10][11][12][13][14][15][16][17][18][19] Catalysts play a crucial role in the production of ethylene/ ENB or ethylene/VNB copolymers, and most of catalysts reported are ansa-metallocenes. As the simplest method of functionalization, copolymerization of olen with polar monomer using early transition metal catalysts is rarely reported because of the highly oxophilic nature of polar monomer.…”

Synthesis of pyrrole‐bridged constrained geometry complexes and their application for olefin polymerization

“…It is also found that the degree of crystallinity (X c %) decreased as the incorporation yield augmented, that is, as the number of branches in the polymer increases, polymer crystallization becomes more and more difficult . However, there are no the fragment of [HHH] and [HHE] (or [OOO] and [OOE]) in copolymer, combined with result of rE•rH = 0 (rE•rO = 0), it is suggested that the catalysts synthesized in this article tend to be alternative copolymerization, and the 1‐hexene (or 1‐octene) comonomer is randomly distributed in the copolymer molecular chain.…”

Polar‐Functionalized, Crosslinkable, Self‐Healing, and Photoresponsive Polyolefins

“…Theutilization of ENB in early transition metal-catalyzed ethylene polymerization has been extensively studied. [37][38][39][40] However,t heir reactivity towards late transition metal catalysts has remained largely unexplored. In this study, ab iaryl-based phosphine sulfonate palladium catalyst (PO-Pd) was used due to its ability to generate high molecular weight polymers (Scheme 1).…”