Synthesis of ultra-high molecular weight poly(ethylene)-co-(1-hexene) copolymers through high-throughput catalyst screening. Issue 10 (2nd February 2021)

• Record Type: Journal Article
• Authors: Williams, Thomas J.; Lamb, Jessica V.; Buffet, Jean-Charles; Khamnaen, Tossapol; O'Hare, Dermot
• Is Part Of: RSC advances. Volume 11:Issue 10(2021)
• Page Start: 5644
• Page End: 5650
• Publication Date: 2021-02-02
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1ra00446h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Permethylindenyl titanium CGCs supported on solid polymethylaluminoxane (sMAO) are investigated as slurry-phase catalysts by high-throughput catalyst screening (copolymerisation of ethylene/1-hexene with incorporation levels up to 14.2 mol%). Abstract : A family of permethylindenyl titanium constrained geometry complexes, Me2 SB( R′ N, 3-R I*)TiX2 ((3-R-η 5 -C9 Me5 )Me2 Si( R′ TiX2 )), supported on solid polymethylaluminoxane (sMAO) are investigated as slurry-phase catalysts for ethylene/H2 homopolymerisation and ethylene/1-hexene copolymerisation by high-throughput catalyst screening. Me2 SB( t Bu N, I*)TiCl2 supported on sMAO [sMAO-Me2 SB( t Bu N, I*)TiCl2 ] is responsive to small quantities of H2 (<1.6%), maintaining high polymerisation activities (up to 4900 kgPE molTi −1 h −1 bar −1 ) and yielding polyethylenes with significantly decreased molecular weight ( M w ) (from 2700 to 41 kDa with 1.6% H2 ). In slurry-phase ethylene/1-hexene copolymerisation studies, a decrease in polymerisation activity and polymer molecular weights compared to ethylene homopolymerisation is observed. Compared to many solid supported system, these complexes all display high 1-hexene incorporation levels up to a maximum incorporation of 14.2 mol% for sMAO-Me2 SB( iPr N, I*)TiCl2 ). We observe a proportionate increase in 1-hexene incorporation with concentration, highlighting the ability of these catalysts to controllably tune the amount of 1-hexene incorporated into the polymer chain to produce linear low-density polyethylene (LLDPE) materials.