Oligomerization of ethylene to linear α-olefins in the presence of complex catalytic systems based on zirconium carboxylates

The study considers the process of ethylene oligomerization in a medium of aliphatic and aromatic solvents in the presence of complex catalytic systems based on zirconium carboxylates, which were obtained from the fractions of naphthenic acids recovered from Baku oils and individual carboxylic acids. It was found that the catalytic activity and the molecular weight distribution (MWD) of the produced oligomeric products depend mostly on the solvent nature and the composition of zirconium complex. The ethylene oligomerization rate in the presence of catalytic systems based on zirconium carboxylates is 2–3 times lower in a medium of aliphatic solvents as compared to aromatic solvents; the obtained product has a narrow MWD and consists predominantly of С4-С10 fractions. Oligomeric products obtained in a medium of aromatic solvents have a broad MWD and in the presence of zirconium carboxylates comprise mostly С4-С18, while in the presence of zirconium naphthenates, С12-С18 and С20 fractions.

Oxidized Maltodextrin: A Novel Ligand for Aluminum–Zirconium Complex Tanning

Hydrogen peroxide (H2O2) oxidized maltodextrin was prepared as the ligand for aluminum–zirconium complex tanning. The effects of catalyst dosage, initiation temperature, and H2O2 dosage on maltodextrin oxidation were investigated. FT-IR analysis demonstrated that carboxyl groups were successfully introduced into oxidized maltodextrin. The carboxyl content and degradation degree of oxidized maltodextrin increased with the increase of H2O2 dosage. Maltodextrin oxidized by 40% H2O2 and 0.015% Cu–Fe catalyst at an initiation temperature of 70°C (OD-40) with moderate carboxyl group (6.75 mmol/g) and molecular weight (Mw 450) promoted the penetration and fixation of aluminum–zirconium salts in leather and showed better tanning performance, such as hydrothermal stability and porosity of leather, than traditional citric acid ligand.

Investigation of a zirconium compound for redox switchable ring opening polymerization

Redox switchable catalysis with a ferrocene Schiff base zirconium complex allowed the synthesis of diblock and triblock copolymers.