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Recycling of Automotive Plastics
Published in Rose A. Ryntz, Philip V. Yaneff, Coatings Of Polymers And Plastics, 2003
6. Aziridine (ethylene imine) crosslinking has been utilized extensively in the coating of interior, low heat-distortion temperature plastics because of its capability to crosslink under ambient conditions. Aziridine reacts with acids to form 2-hydroxyamides, which can further rearrange to the acid salt of 2-aminoester. Polyfunctional aziridines are generally achieved through the Michael addition of 3 moles of aziridine with 1 mole of trimethylol propane triacry-late. Polyaziridines can be formulated in water but usually only as two-pack systems. The pH is adjusted on the order of 8.5 to 9 to control the reactivity ratio of aziridine/carboxylic acid versus the competitive reaction with water. A major problem associated with aziridine, however, is the monomer's high toxic-ity and carcinogenicity.
Theoretical study on chemical fixation of carbon dioxide with aziridine into cyclic carbamate catalysed by purine/HI system
Published in Molecular Physics, 2021
Teshome Mender Gezhagn, Abdudin Geremu Temam, Teshome Abute Lelisho
Initially the reaction path for the cycloaddition of CO2 with aziridine was calculated without the catalysts. The bimolecular complex was formed by the two reacting species (aziridine and CO2). The equilibrium structure of the pre-reaction complex was obtained by optimising aziridine and CO2 together at B3LYP/6-31+G(d,p) level in the gas phase. We have perceived both non-covalent and hydrogen bonding interactions in the complex. The hydrogen bonding interaction happens between the hydrogen atom of the aziridine and oxygen atom of CO2. The non-covalent interactions, as Lewis acid/base interaction, were observed between aziridine and CO2, where CO2 was supposed as Lewis acid and aziridine as Lewis base. The cycloaddition reaction between aziridine and CO2 proceeds to the product cyclic carbamate through a single-step concerted mechanism (Figure 1).
The coordination of a multidentate NxOy-donor (x and y ≤ 2) oxazolidine-based ligand with Cd(II) and Hg(II); Structural, spectral, and theoretical studies
Published in Journal of Coordination Chemistry, 2018
Zahra Mardani, Vali Golsanamlou, Saba Khodavandegar, Keyvan Moeini, Alexandra M. Z. Slawin, J. Derek Woollins
Several substituted oxazolidines have been investigated extensively because of their importance as pharmacologically active compounds (such as antidiabetic [1], anticonvulsant [2], antitubercular [3], and aldose reductase inhibitors [4]), chiral auxiliaries in the synthesis of a variety of chiral compounds, chain-protecting groups for amino alcohols [5,6], crosslinking agents [7] for the stabilization of collagen [8,9], linkers in solid-phase synthesis of peptide aldehydes processes [10], optical probe applications [11] and fungicidal activities [12]. Usually, 1,3-oxazolidines are synthesized by the condensation of 1,2-amino alcohols with carbonyl compounds [13]. Some other approaches found in the literature include double-Michael reactions of acetylenes and β-amino alcohols [14], aza-Wacker type reaction of β-amino alcohols with alkenes [15], aziridines with vinyl arenes [16] and tandem ring-opening/closing reaction of aziridine itself [16]. One other method is the ring formation process from α-hydroxyesters [17] or α-hydroxyamides [18] by treatment with a reagent already carrying the carbonyl function and α-hydroxycarboxylic acids with carbodiimide [19].
A comprehensive review of corrosion inhibition of aluminium alloys by green inhibitors
Published in Canadian Metallurgical Quarterly, 2023
Mulky Lavanya, Joydeep Ghosal, Padmalatha Rao
In drug structures, carbocyclic and heterocyclic systems are standard. The most common ring systems are five and six members. However, small ring systems are also prevalent (for example, the aziridine ring in mitomycin C and the cyclopropane ring in ciprofloxacin). Aromatic or pseudo-aromatic systems make up the majority of five- and six-membered systems. As a result, substituted benzene rings are widespread in drug structures, as are heterocycles, including imidazoles, pyridines, thiophenes, isoxazoles, furans and others. Corrosion-prevention qualities of numerous medications have received too much attention in recent years because of the structural proximity indicated above [44].