Synthesis of zirconocene complexes and their use in slurry-phase polymerisation of ethylene. Issue 19 (19th March 2021)

• Record Type: Journal Article
• Authors: Angpanitcharoen, Phakpoom; Lamb, Jessica V.; Buffet, Jean-Charles; Turner, Zoë R.; O'Hare, Dermot
• Is Part Of: RSC advances. Volume 11:Issue 19(2021)
• Page Start: 11529
• Page End: 11535
• Publication Date: 2021-03-19
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1ra01912k
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A new family of zirconocene complexes of the type ( 3-R Ind # )2 ZrX2 (where Ind # = C6 Me5 H and R = Me, Et and Ph) have been synthesised and fully characterised. Abstract : A new family of zirconocene complexes of the type ( 3-R Ind # )2 ZrX2 (where Ind # = C6 Me5 H and R = Me, Et and Ph) have been synthesised and fully characterised. Six new crystal structures have been reported ( meso -( 3-Et Ind # )2 ZrBr2, rac -( 3-Et Ind # )2 ZrCl2, rac -( 3-Et Ind # )2 Zr(CH2 Ph)2, meso -( 3-Et Ind # )2 Zr(CH2 Ph)2, meso -( 3-Me Ind # )2 ZrBr2 and meso -( 3-Me Ind # )2 Zr(CH2 Ph)2 ). The complexes were studied for slurry-phase ethylene polymerisation when immobilised on solid polymethylaluminoxane (sMAO). Variation in the initiation group was found to have greater influence over polymerisation activity for meso -catalysts than rac -catalysts, with meso -alkyl catalysts showing higher polymerisation activities than meso -halide. Below 70 °C, polymerisation activity follows the order sMAO- meso -( 3-Et Ind # )2 Zr(CH2 Ph)2, sMAO- meso -( 3-Et Ind # )2 ZrCl2 and sMAO- meso -( 3-Et Ind # )2 ZrBr2 (activities of 657, 561, and 452 kgPE molM −1 h −1 bar −1, respectively). sMAO- meso -( 3-Et Ind # )2 ZrBr2 produces HDPE with the highest molecular weight, followed by sMAO- meso -( 3-Et Ind # )2 ZrCl2 and sMAO- meso -( 3-Et Ind # )2 Zr(CH2 Ph)2 ( M w of 503, 406, and 345 kg mol −1, respectively, at 50 °C). sMAO- meso -( 3-Me Ind # )2 ZrBr2 produced HDPE with almost identical molecular weights to sMAO- meso -( 3-Et Ind # )2 ZrCl2 (395 kg mol −1 at 50 °C).