Isocyanates
Mostrando 1-12 de 22 artigos, teses e dissertações.
-
1. Heteroannulation Reaction of α-Aminoketones for the Efficient Synthesis of 4-Imidazolin-2-ones and 2-Thiones
The hydrogenation of α-oximinoketones in methanol/HCl afforded α-aminoketones, which were applied without purification to the synthesis of 4-imidazolin-2-ones and 2-thiones, including chiral derivatives. The latter two series were obtained in high yields by a heteroannulation reaction of α-aminoketones with isocyanates and isothiocyanates, respectively. A
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
2. Síntesis de microcápsulas de poliurea a partir de aminas renovables, mediante doble emulsificación
This paper reports on the microencapsulation of a commercial perfume by means of a double emulsification, where the polyurea shell was synthesized by the reaction of lysine with two commercial di-isocyanates (aromatic and aliphatic). In the synthesis the factors evaluated were the amine:di-isocyanate molar ratio and the type of emulsifier. The particle size
Polímeros. Publicado em: 13/05/2011
-
3. Reaction of aromatic carboxylic acids with isocyanates using ionic liquids as novel and efficient media
Líquidos iônicos (ILs) baseados em 1,3-dialquilimidazólio e amônea têm sido usados como meio de reação eficiente para amidação de diversos ácidos carboxílicos com isocianatos. Esse método tem larga aplicação e o procedimento é suave e eficiente quando comparado aos métodos existentes, baseados em solventes convencionais. O "projeto" adequado
Journal of the Brazilian Chemical Society. Publicado em: 2007
-
4. Preparation and characterization of termoplastic starches / Preparação e caracterização de amidos termoplásticos
Este trabalho teve como objetivo estudar o processo de plasticização do amido via mistura física e por reação química para a produção de novos materiais. A plasticização via mistura física foi realizada empregando-se como agentes plasticização diferentes compostos hidroxilados. Os amidos termoplásticos (TPS) foram processadas em misturador inte
Publicado em: 2004
-
5. Solid polymer electrolytes based on polysacharide: synthesis and characterization. / Eletrólitos sólidos poliméricos à base de polissacarídeos: síntese e caracterização.
The synthesis and characterization of new types of solid polymer electrolytes based on hydroxyethyl and hydroxypropyl cellulose grafted with different polyethers were investigated. The synthesis is based on the reaction between the cellulose derivative and mono and difunctional isocyanates prepared from amines of polyethylene oxide and polypropylene oxide. I
Publicado em: 2000
-
6. Outcome determinants for isocyanate induced occupational asthma among compensation claimants.
OBJECTIVES: To compare the outcome of occupational asthma (OA) induced by isocyanates in Ontario (where a surveillance programme for exposed workers has been in place for over 15 years), with the outcome of OA induced by other work agents. METHODS: Compensated OA claims during the period 1984-88 in Ontario were retrospectively reviewed in a standardised way.
-
7. Amines: possible causative agents in the development of bronchial hyperreactivity in workers manufacturing polyurethanes from isocyanates.
Investigations of respiratory symptoms among workers in a factory producing polyurethane foam included measurement of air pollution with amines and isocyanates and a simultaneous health investigation of the exposed workers. An increased bronchial reactivity to inhaled methacholine was found in the study group compared with two unexposed control groups. This
-
8. Isocyanates, Polyurethane Paints, and Asthma
-
9. Injury to the Respiratory Tract by Isocyanates Used in Making Lacquers
-
10. Occupational asthma and extrinsic alveolitis due to isocyanates: current status and perspectives.
-
11. Isocyanates in Industry—Operating and Medical Codes of Practice. A Report of the Isocyanate Subcommittee, Health Advisory Commission
-
12. Hypersensitivity pneumonitis after exposure to isocyanates.
Four patients exposed to isocyanate vapour developed dyspnoea associated with restriction and reduced gas transfer as well as moderate airways obstruction on lung function testing. In one patient bilateral radiographic shadowing was present and an open lung biopsy was performed. The microscopic appearances ranged from acute inflammation to end-stage fibrosis