Removal of peroxide impurities by zeolites

Wortel, Th. M.; Bekkum, H. van

doi:10.1021/jo01311a042

Cited by 20 publications

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“…All the LTL nanozeolites also adsorbed hydroperoxides based on the two bands at 881 and 865 cm −1 , which corresponded to the bending motions of O–O–H (inset of Fig. 9 ) [ 35 , 36 ].…”

Section: Resultsmentioning

confidence: 99%

“…Initially, triglycerides are oxidized to hydroperoxides’ primary oxidation products. In the presence of LTL zeolites, decomposition of ROOH intermediates to secondary oxidation products (alcohols, water, aldehydes, carboxylic acids) is slowing down due to the stabilization of these intermediates by the extra-framework cations [ 35 ]. This phenomenon is well demonstrated by the LTL zeolites containing highly polarizable and electropositive K + and Ca 2+ cations where the electron density of ROO − is significantly reduced through counter-ion balancing.…”

Section: Resultsmentioning

confidence: 99%

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Effect of Extra-Framework Cations of LTL Nanozeolites to Inhibit Oil Oxidation

et al. 2015

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Lubricant oils take significant part in current health and environmental considerations since they are an integral and indispensable component of modern technology. Antioxidants are probably the most important additives used in oils because oxidative deterioration plays a major role in oil degradation. Zeolite nanoparticles (NPs) have been proven as another option as green antioxidants in oil formulation. The anti-oxidative behavior of zeolite NPs is obvious; however, the phenomenon is still under investigation. Herein, a study of the effect of extra-framework cations stabilized on Linde Type L (LTL) zeolite NPs (ca. 20 nm) on inhibition of oxidation in palm oil-based lubricant oil is reported. Hydrophilic LTL zeolites with a Si/Al ratio of 3.2 containing four different inorganic cations (Li+, Na+, K+, Ca2+) were applied. The oxidation of the lubricant oil was followed by visual observation, colorimetry, fourier transform infrared (FTIR) spectroscopy, 1H NMR spectroscopy, total acid number (TAN), and rheology analyses. The effect of extra-framework cations to slow down the rate of oil oxidation and to control the viscosity of oil is demonstrated. The degradation rate of the lubricant oil samples is decreased considerably as the polarizability of cation is increased with the presence of zeolite NPs. More importantly, the microporous zeolite NPs have a great influence in halting the steps that lead to the polymerization of the oils and thus increasing the lifetime of oils.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Effect of Extra-Framework Cations of LTL Nanozeolites to Inhibit Oil Oxidation

et al. 2015

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“…We did not test for the removal of peroxides from solvents such as tetrahydrofuran, so the usual precautions should be followed (such as testing for the presence of peroxides or performing a chemical quench of these reactive species) with solvents for which the presence of peroxides may be an issue. For a discussion on the removal of peroxides, including the use of chemical and absorptive methods (with alumina and zeolites), the reader is advised to consult ref ].…”

Section: Discussionmentioning

confidence: 99%

Drying of Organic Solvents: Quantitative Evaluation of the Efficiency of Several Desiccants

2010

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Various commonly used organic solvents were dried with several different drying agents. A glovebox-bound coulometric Karl Fischer apparatus with a two-compartment measuring cell was used to determine the efficiency of the drying process. Recommendations are made relating to optimum drying agents/conditions that can be used to rapidly and reliably generate solvents with low residual water content by means of commonly available materials found in most synthesis laboratories. The practical method provides for safer handling and drying of solvents than methods calling for the use of reactive metals, metal hydrides, or solvent distillation.

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“…Our interpretation of these observations is that both MBT and MBTS are unstable as dilute solutions in THF, the presence of which is necessary to dissolve MBTS. This solvent contains peroxides (Wortel and van Bekkum, 1980), which may promote the interconversion. To reduce peroxide levels and minimize oxidation, we used freshly distilled THF in the dosing preparations and used the preparations within 24 h.…”

Section: Intravenous Dosingmentioning

confidence: 99%

Disposition of 2‐mercaptobenzothia2ole and 2‐mercaptobenzothiazole disulfide in rats dosed intravenously, orally, and topically and in guinea pigs dosed topically

Dareer

Kalin

Tillery

et al. 1989

Journal of Toxicology and Environmental Health

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To determine the metabolic disposition of [14C]-2-mercaptobenzothiazole (MBT) and [14C]-2-mercaptobenzothiazole disulfide (MBTS), male and female rats were dosed topically. Topical doses were 36.1 micrograms/animal for [14C]MBT and 33.6 micrograms/animal for [14C]MBTS. Although more MBT passed through the skin than MBTS and although, relative to rats, guinea pigs absorbed a greater percentage of the dose (33.4% compared to 16.1-17.5% of the MBT and 12.2% compared to 5.94-7.87% for MBTS), the disposition of radioactivity derived from the two compounds was similar. Washing of the skin removed more of the radioactivity from guinea pigs than from rats. For both sexes of rats dosed intravenously with [14C]MBT (0.602 mg/kg) or [14C]MBTS (0.571 mg/kg), disposition of the compounds was similar. In 72 h, 90.9-101% of the dose appeared in the urine and 3.79-15.1% in the feces. At this time, a small portion of the administered radioactivity (1.52-1.96% of the dose) remained associated with erythrocytes. Oral dosing of rats for 14 d with unlabeled MBT (0.510 mg/kg.d) prior to a single dose of [14C]MBT (0.503 mg/kg) or with unlabeled MBTS (0.521 mg/kg.d) prior to a single dose of [14C]MBTS (0.730 mg/kg). For both sexes, disposition of the compounds was similar. At 96 h after dosing, a small portion of the administered radioactivity (1.20-1.69% of the dose) remained associated with erythrocytes, most of which was bound to the membranes. For both compounds and sexes, 60.8-101% of the radioactivity administered appeared in the urine and 3.46-9.99% in the feces in 96 h. At the time, only trace amounts of radioactivity remained in tissues other than blood. Of these tissues, thyroid contained the highest concentration. In the urine, there was a detectable MBT or MBTS, but there were two metabolites, one of which was identified as a thioglucuronide derivative of MBT. The other was possibly a sulfonic acid derivative of MBT. In conclusion, there were similarities in absorption, distribution, and metabolism of [14C]MBT and [14C]MBTS in rats and in guinea pigs, indicating that [14C]MBTS was readily converted to [14C]MBT.

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Removal of peroxide impurities by zeolites

Cited by 20 publications

References 0 publications

Effect of Extra-Framework Cations of LTL Nanozeolites to Inhibit Oil Oxidation

Effect of Extra-Framework Cations of LTL Nanozeolites to Inhibit Oil Oxidation

Drying of Organic Solvents: Quantitative Evaluation of the Efficiency of Several Desiccants

Disposition of 2‐mercaptobenzothia2ole and 2‐mercaptobenzothiazole disulfide in rats dosed intravenously, orally, and topically and in guinea pigs dosed topically

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