Ethylene polymerization using vanadium catalyst supported on silica modified by pyridinium ionic liquid

Abstract

Vanadium catalyst systems (SIL1–3A(B)/V) for ethylene polymerization were obtained by immobilization of the Cp2VCl2 precursor (V) in the ionic liquid 1‐[3‐(triethoxysilyl)propyl]pyridinium chloride (IL), modified by AlCl3 and AlEtCl2 (A) or AlEt2Cl (B), and supported on three types of silica carrier S1–3. The properties of the ionic liquid supports were determined using Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller measurements, scanning electron microscopy and elemental analysis. The best results (above 2 tons PE (mol V)−1 (0.5 h)−1) were obtained using the catalyst system SIL3B/V. Addition of ethyl trichloroacetate is possible in the ionic liquid medium and it further increases the activity up to 7 tons PE (mol V)−1 (0.5 h)−1. In contrast, application of the imidazolium ionic liquid to the SIL system or application the analogous catalyst system without the ionic liquid results in lower activities. The obtained polyethylene (PE) is a linear polymer, with molecular weight (Mw) of over 106 g mol−1 and molecular weight distribution (Mw/Mn) in the range 1.6–1.9, and has a characteristic fluffy or fibrous shape. In contrast, the PE samples obtained using the systems without ionic liquid reveal broader Mw/Mn (2.5–3.7) and replicate the support morphology. © 2016 Society of Chemical Industry

Structural and Thermal Properties of Ethylene-Norbornene Copolymers Obtained Using Vanadium Homogeneous and SIL Catalysts

“…The E-NB copolymers were prepared according to the procedures previously published [ 21 , 26 , 44 , 45 , 46 ]. The vanadium complexes with the following ligands were applied for the copolymerization reaction: 2-(4,5-dihydro-1,3-oxazolin-2-yl)phenol ( C1 ), 2-(4-methyl-4,5-dihydro-1,3-oxazolin-2-yl)phenol ( C2 ), 2-(5,6-dihydro-4H-1,3-oxazin-2-yl)phenol ( C3 ), 2-(1,3-oxazolin-2-yl)pyridine ( C4 ), 2,6-bis(1,3-oxazolin-2-yl)pyridine ( C5 ) and cyclopentadienyl ( C6 ) ( Figure 1 ).…”

“…The SIL systems combine the advantages of homogeneous and heterogeneous catalysis, while reducing their disadvantages [ 42 , 43 ]. Moreover, our group showed that the SIL systems were active both in ethylene polymerization and copolymerization of ethylene with α-olefins and cyclic olefins [ 21 , 44 , 46 ].…”

Copolymerization of ethylene with norbornene or 1-octene using supported ionic liquid systems

“…Based on our previous study [33], the silica material with the narrow, but deep pores was chosen. The Brunauer-Emmett-Teller (BET) analysis shows that for this silica support, introduction of the ionic liquid and further modification by creation of more bulky chloroaluminate anion result in decrease of the surface area from 457 to 67 m 2 /g, like also in decreases of the pore volume from 0.56 cm 3 /g to 0.28 cm SEM images (Fig.…”

“…Vanadium salen complex, N,N 0 -ethylenebis(5-chlorosalicylideneiminato)vanadium(IV) dichloride-VCl 2 (salenCl 2 ), was obtained and prepared according to the published procedure [28]. Ionic liquid, 1-[3-(triethoxysilyl)propyl]pyridinium chloride, was obtained according to the published procedure [33].…”

“…Thus, the SIL systems combine the advantages of both homogeneous and heterogeneous catalysts while reducing their disadvantages [30]. The SIL systems can be successfully applied for ethylene polymerization [31][32][33]. The silica covered by imidiazolium or pyridinium chloroaluminate ionic liquid is applied as support of the zirconium, titanium, or vanadium catalysts.…”