Polyethylene with Reverse Co-monomer Incorporation: From an Industrial Serendipitous Discovery to Fundamental Understanding.
A triethylaluminium(TEAl)-modified Phillips ethylene polymerisation Cr/Ti/SiO2 catalyst has been developed with two distinct active regions positioned respectively in the inner core and outer shell of the catalyst particle. DRIFTS, EPR, UV-Vis-NIR DRS, STXM, SEM-EDX and GPC-IR studies revealed that the catalyst produces simultaneously two different polymers, i.e., low molecular weight linear-chain polyethylene in the Ti-abundant catalyst particle shell and high molecular weight short-chain branched polyethylene in the Ti-scarce catalyst particle core. Co-monomers for the short-chain branched polymer were generated in situ within the TEAl-impregnated confined space of the Ti-scarce catalyst particle core in close proximity to the active sites that produced the high molecular weight polymer. These results demonstrate that the catalyst particle architecture directly affects polymer composition, offering the perspective of making high-performance polyethylene from a single reactor system using this modified Phillips catalyst.
Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (The Netherlands).
Dimitrije
D
Cicmil
Refining & Chemicals, Total Research and Technology Feluy, Zone Industrielle C, 7181 Seneffe (Belgium).
Jurjen
J
Meeuwissen
Refining & Chemicals, Total Research and Technology Feluy, Zone Industrielle C, 7181 Seneffe (Belgium).
Aurélien
A
Vantomme
Soft X-ray Spectromicroscopy, Canadian Light Source Inc., 44 Innovation Boulevard, SK S7N 2V3 Saskatoon (Canada).
Jian
J
Wang
Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (The Netherlands).
Ilse K
IK
van Ravenhorst
Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (The Netherlands).
Hendrik E
HE
van der Bij
Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (The Netherlands).
Ara
A
Muñoz-Murillo
Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (The Netherlands). b.m.weckhuysen@uu.nl.
Bert M
BM
Weckhuysen
Phillips catalyst; heterogeneous catalysis; in situ oligomerisation; polyethylene; scanning transmission x-ray microscopy