Search

Waste newspaper (WP) was first co-pyrolyzed with high-density polyethylene (HDPE) using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) to enhance the yields of alcohols and hydrocarbons. The effects of WP: HDPE feed ratio (100:0, 75:25, 50:50, 25:75, 0:100) and temperature (500-800°C) on products distribution were investigated and the interaction mechanism during co-pyrolysis was also proposed. Maximum yields of alcohols and hydrocarbons reached 85.88% (feed ratio 50:50wt.%, 600°C). Hydrogen supplements and deoxidation by HDPE and subsequently fragments recombination result in the conversion of aldehydes and ketones into branched hydrocarbons. Radicals from WP degradation favor the secondary crack for HDPE products resulting in the formation of linear hydrocarbons with low carbon number. Hydrocarbons with activated radical site from HDPE degradation were interacted with hydroxyl from WP degradation promoting the formation of linear long chain alcohols. Moreover, co-pyrolysis significantly enhanced condensable oil qualities, which were close to commercial diesel No. 0., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The objective of this work was to investigate the influence of hydrogen bonds between fibres on static and dynamic strength properties of paper. A commercial bleached pinewood kraft pulp was soaked in water, refined in a PFI, and used to form paper webs in different solvents, such as water, methanol, ethanol, n-propanol and n-butanol, to determine the effect of their dipole moment on static and dynamic strength properties of resulting paper sheets. Paper which was formed in water, being the solvent of the highest dipole moment among the tested ones, showed the highest breaking length and tear resistance. When paper webs were formed in n-butanol, which was the least polar among the solvents, these parameters were reduced by around 75%. These results provide evidence of the importance of water in paper web formation and strong impact of hydrogen bonds between fibres on strength properties of paper. [ABSTRACT FROM AUTHOR]

Noncanonical amino acids (ncAAs) containing tertiary alcohols are valuable as precursors of natural products and active pharmaceutical ingredients. However, the assembly of such ncAA scaffolds from simple material by C-C bond formation remains a challenging task due to the presence of multiple stereocenters and large steric hindrance. In this study, we present a novel solution to this problem through highly selective enzymatic decarboxylative aldol addition. This method allows for the streamlined assembly of multifunctionalized ncAAs with γ-tertiary alcohols from readily available materials, such as L -aspartatic acid and isatins, vicinal diones and keto esters. The modularity of electrophiles furnished four classes of ncAAs with decent efficiency as well as excellent site and stereocontrol. Computational modeling was employed to gain detailed insight into the catalytic mechanism and to provide a rationale for the observed selectivities. The method offers a single-step approach to producing multifunctionalized ncAAs, which can be directly utilized in peptide synthesis and bioactivity assessment., (© 2023 Wiley-VCH GmbH.)

This work investigates which acid can mainly lead to the reduction of alcohols contents in insulating oil during transformer oil-paper insulation aging. In terms of the activation free energy barrier theory, the microscopic mechanisms for the preferential reactions of methanol and ethanol with formic, acetic, naphthenic and stearic acids are analyzed. It is revealed that the decrease in alcohols concentrations in the middle and late stages of transformer oil-paper insulation aging is mainly caused by the reaction between alcohols and naphthenic acid. The results are cross-validated by utilizing the frontier molecular orbital theory and accelerated thermal aging experiments. Additionally, it is observed that methanol is more susceptible to the effect of acids than ethanol in the middle and late stages of aging. The obtained conclusions, in this paper, could provide a theoretical basis for using alcohols in oil as aging indicators to characterize the full-stage aging status of transformer paper insulation. [ABSTRACT FROM AUTHOR]

We developed a chiral symmetry breaking method for monoacylated meso diols. The X-ray crystal structure analysis of monoacylated 1,4-anhydroerythritols, meso cyclic diols with a cis configuration, revealed that the O-(p-anisoyl) derivative crystallized as a racemic conglomerate of the P2 1 2 1 2 1 crystal system. It was confirmed that the substrate racemized by intramolecular transfer of the acyl group in the presence of a catalytic amount of base. Evaporating the solvent gradually from the solution or Viedma ripening to promote crystallization-induced deracemization efficiently led to enantiomer crystals. These results provide the first successful example of asymmetric expression and amplification by deracemization of sugar derivatives without an external chemical chiral source. Furthermore, we applied this methodology to acyclic meso-1,2-diols. Three O-monoacylated substrates were successfully deracemized to 99 % ee by Viedma ripening. We also developed asymmetric desymmetrization of meso-1,2-diols by combining acylation and crystallization-induced deracemization., (© 2022 Wiley-VCH GmbH.)

Chiral Lewis acid-catalyzed asymmetric alcohol addition reactions to cyclic carbonyl ylides generated from N-(α-diazocarbonyl)-2-oxazolidinones featuring a dual catalytic system are reported. Construction of a chiral quaternary heteroatom-substituted carbon center was accomplished in which the unique heterobicycles were obtained in good yields with high stereoselection. The alcohol adducts were successfully converted to optically active oxazolidine-2,4-diones by hydrolysis. Mechanistic studies by DFT calculations revealed that alcohols could be activated by Lewis acids, enabling enantioselective protonation of the carbonyl ylides., (© 2021 Wiley-VCH GmbH.)

Fluorotelomer alcohols (FTOHs) are widely used as industrial raw materials due to their unique hydrophobic and oleophobic properties. However, because of accidental exposure to products containing FTOHs or with the widespread use of FTOHs, they tend to contaminate the water and the soil. There are reports demonstrating that FTOHs can cause various harmful effects in animals and humans (for example, neurotoxicity, hepatotoxicity, nephrotoxicity, immunotoxicity, endocrine-disrupting activity, and developmental and reproductive toxicities). Oxidative stress is related to a variety of toxic effects induced by FTOHs. To date, few reviews have addressed the relationship between the toxicity of FTOHs and oxidative stress. This article summarises research demonstrating that the toxicity induced by FTOHs correlates with oxidative stress and metabolism. Furthermore, during the metabolic process of FTOHs, a number of cytochrome P450 enzymes (CYP450) are involved and many metabolites are produced by these enzymes, which can induce oxidative stress. This is also reviewed., (© 2020. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

The quality perception of gluten-free beer was explored using conjoint analysis with a panel of Polish millennials (n = 200; aged 20 to 35), who were given 64 gluten-free beer concepts to evaluate and score on a 9-point scale of interest (1 = not interested at all; 9 = extremely interested). The constituent factors of the beer concepts were alcohol content, color, type of malt, price, drinking location and occasion, bottle size, label claims, type of farming, type of brewer, and bottle closure. Consumers judged price (38.4%) and alcohol (28.8%) five times more important than the other factors. Bottle size (5.3%), claims (4.8%), type of brewer (4.8%), malt type (4.6%), bottle closure (4.0%), beer color (3.6%), drinking location (2.3%), drinking occasion (2.0%), and type of farming (1.3%) were considered of little importance. The interest of Polish Millennials in gluten-free beer resulted moderate and not linked to medical needs. Males were more interested in gluten-free beers and gave more importance to alcohol content and less importance to price, compared to females. However, for both genders, interest and price were inversely correlated, while interest and alcohol content were directly correlated. PRACTICAL APPLICATION: The identification of the product factors that are preferred by consumers is paramount to translate consumers' needs and expectations into a beer designed to produce the best possible product in a relatively short period. Including information directly obtained from consumers before final design decisions are taken on the final beer output, helps ensuring development directions are on target and constitutes a cost-competitive approach to product development., (© 2019 Institute of Food Technologists®.)