Tuning Polyethylene Molecular Weight Distributions Using Catalyst Support Composition

Abstract

Bimodal polyethylene is generated from a single immobilized catalyst on a single support under a single set of reaction conditions without introducing chain transfer agents. Using rac-ethylene­bis­(1-indenyl)­zirconium dichloride [(EBI)­ZrCl2] immobilized on a nickel-containing layered double hydroxide (LDH) support produces two distinct molecular weight distributions. The ratio of these two distinct fractions can be tuned by varying the LDH support as well as by changing the reaction conditions.

Enhancing Metallocene Catalyst Activity: Utilizing Layered Double Hydroxide for Ethylene–Propylene Copolymerization

“…Other studies reported the application of LDH-supported metallocene catalysts for ethylene polymerization. [12,36,35] Kenyon et al reported the LDH-supported catalysts, thereby paying more attention to catalyst immobilization and tuning polyethylene properties. [36] In another study by Kenyon et al, the effect of LDH composition on the catalytic performance of metallocene was investigated.…”

Tuning Polymer Molecular Weight Distribution in Cationic RAFT Polymerization by Mixing Chain Transfer Agents†

“…[ 1‐4 ] However, efficient methods to precisely tune the polymer MWD in cationic polymerization haven't been well explored, which is essential for polymer properties such as mechanical properties, crystallization behavior, and viscoelasticity. [ 5‐7 ] In fact, it was until recent years some efficient strategies to tune polymer MWD have been developed such as metered additions of initiating species in controlled polymerization, [ 8‐9 ] blending polymers directly, [ 10‐12 ] or through combination with flow chemistry, [ 13‐18 ] tuning the components of the polymerization systems, [ 19‐26 ] and adjusting the external stimulus. [ 27‐34 ] In terms of cationic polymerization, Aoshima et al .…”

Structure–activity relationships of LDH catalysts for the glucose-to-fructose isomerisation in ethanol

“…For that reason, layered double hydroxides (LDHs), one family of the most promising solid bases with two-dimensional, ion-intercalated, anisotropic layered structure have attracted significant interest. [38][39][40][41] These anionic clays consist of octahedrally coordinated metal hydroxide layers in which the bivalent cations are partially substituted by trivalent cations, generally. 42,43 As a result of the isomorphous substitution, the hydroxide layers are positively charged which is compensated by the interlamellar, solvated anions.…”