Maleimide modified epoxy compounds were prepared by reacting N-(4-hydroxyphenyl) maleimide (HPM) with diglycidylether of bisphenol-A. Triphenylphosphine was used as a catalyst and methylethylketone as a solvent. The resulting compound possessed both the oxirane ring and maleimide group. The curing reaction of the maleimide-epoxy compound with amine curing agents such as ethylenediamine (EDA), diethylenetriamine (DETA) and triethylenetetramine (TETA) were studied. Incorporation of maleimide groups in the epoxy resin provides cyclic imide structure and high cross-linking density to the cured resins. The cured samples were found to have good thermal stability, chemical (acid/alkali/solvent) and water absorption resistance. The morphology of cured epoxy systems were also studied by scanning electron microscopy (SEM).

Thiophosgene and 1-chloroethyl chlorothionoformate react readily with tertiary AMINES, and give the dialkylamine hydrochloride after hydrolysis of the initial product with water. Benzyl and allyl groups are cleaved in preference to methyl and other alkyl groups. The rection with the isoquinoline alkaloid narcotine occurs particularly easily.

The electrochemical coating technique was used for the preparation of a polypyrrole coating on a stainless-steel wire, and applied as a fibre for solid phase microextraction (SPME). The polypyrrole fibre was employed for analyzing four volatile ALIPHATIC AMINES (ethylamine, propylamine, butylamine and pentylamine) in water by headspace SPME using gas chromatography-flame ionization detection (GC-FID). Results showed that this fibre coating is suitable for the successful extraction of the target analytes. The effects of the extraction parameters including exposure time, sampling temperature, salt concentration, and stirring rate on the extraction efficiency was optimized. Relative standard deviations (RSDs) were determined ≤4.3%. The correlation coefficient was satisfactory (r2 > 0.98) for the studied analytes. Detection limits were between 0.9 and 1.6mg.L-1. Good recoveries (99-106 %) were obtained when spiked water and wastewater samples were analyzed

A total of 11 new a,a-dioxoketene- N,S -acetals (2a–2k) and two new a,a-dioxoketene- N,N -acetals (3j and 3k) have been synthesised by treating 3-[bis(methylthiol)methylene]pentane-2,4-dione (1) with increasing mole ratios of secondary ALIPHATIC AMINES at room temperature, in either toluene or ethanol. Eight non-cyclic N -methylalkyl and N -ethylalkyl AMINES and the azacyclopentane of pyrrolidine yielded exclusively mono-substituted N,S -acetals (2a–2i), while the azacyclohexanes of piperidine and morpholine yielded the mono-substituted N,S -acetals 2j and 2k and the double-substituted N,N -acetals 3j and 3k. The conversion yields for the reactions in ethanol are considerably higher than those in toluene. Furthermore, the secondary ALIPHATIC AMINES with an N -methylalkyl moiety, which have one primary a-carbon and less steric crowding around the nucleophilic nitrogen, appear to be more reactive towards 1 than those with the N -ethylalkyl group, which have two primary a-carbons; further, the latter AMINES are more reactive than the AMINES with secondary a-carbons.

Objectives: This study aims to conduct a quantitative risk analysis and evaluate control measures for workplace exposure to ALIPHATIC AMINES, focusing on a case study in the foundry sector.Methods: The study comprised four main phases: risk analysis, determination of weight coefficients for reducing exposure probability, uncertainty analysis, and evaluation of implemented risk control measures. During the risk analysis phase, air samples were collected and analyzed to identify the presence of ALIPHATIC AMINES and assess associated risk levels. Weight coefficients for reducing exposure probability were established using the Full Consistency Method (FUCOM), where a panel of experts ranked workplace, administrative, and individual controls. Uncertainty analysis utilized the Monte Carlo (MC) method to generate triangular distributions for the weight coefficients, enabling a comprehensive evaluation of potential uncertainties.Results: Environmental monitoring in the industry revealed the presence of five ALIPHATIC AMINES, with specific units (B and C) showing exposure risks to tri-ethylamine above the adjusted TLV. Additionally, the risk of exposure to mixed ALIPHATIC AMINES was significant across all units. Deterministic weighting using the FUCOM method allocated the highest importance (0.66) to workplace controls for reducing risk probability. Uncertainty analysis using MC adjusted the weighted coefficients to 0.78 for workplace controls, 0.18 for administrative controls, and 0.13 for individual controls, with confidence levels of 85-95%. Evaluation of implemented controls in the industry indicated specific effectiveness across different control levels, with experts estimating risk reduction levels of 10.4% for individual controls, 9% for administrative controls, and 7.8% for workplace controls.Conclusion: These findings highlight the critical importance of implementing and evaluating control measures for workplace exposure to ALIPHATIC AMINES in the studied industry.

A phosgene-free synthesis of symmetrical N,N"-disubstituted ureas by the reaction of aromatic and ALIPHATIC primary AMINES and urea promoted by microwave irradiation in the presence of a suitable energy-transfer solvent such as N,N-dimethylacetamide is described.