| Texto completo | |
| Autor(es): |
Medeiros, R. S.
;
Ferreira, A. P. G.
;
Cavalheiro, E. T. G.
Número total de Autores: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY; v. 142, n. 2, p. 11-pg., 2020-02-08. |
| Resumo | |
Nonsteroidal anti-inflammatory drugs naproxen (NAP) ((+)-(S)-2-(6-methoxynaphthalen-2-yl) propionic acid) and ketoprofen (KET) (RS)-(2-(3-benzoylphenyl)-propionic acid) were investigated by thermoanalytical techniques (TG/DTG/DTA, DSC and hot-stage microscopy) and evolved gas analysis (TG-FTIR) for evaluating their thermal behavior. In air, TG curve of NAP presented one mass loss step followed by the burning of carbonaceous material, with final residue of 1.5%, while in nitrogen, a single mass loss step was observed. After melting, if the sample is submitted to an isotherm it evaporates. According to DSC curve, NAP melts at 153.5 degrees C ( increment H-fus = 31.6 kJ mol(-1); increment S-fus = 73.5 J K-1 mol(-1)) and recrystallizes in the cooling step. These events were confirmed by hot-stage microscopy. TG-FTIR studies revealed that NAP decomposes by releasing 2-methoxynaphthalene and propionic acid. Ketoprofen TG curves in both atmospheres presented a single mass loss. When the sample was kept under isotherm, after melting, it evaporated. From DSC data, the melting at 93.3 degrees C ( increment H-fus=28.4 kJ mol(-1), increment S-fus = 76.9 J K-1 mol(-1)) was observed, without crystallization or cooling. (AU) | |
| Processo FAPESP: | 17/04211-7 - Desenvolvimento de tintas à base de nanopartículas metálicas e polímeros para construção de eletrodos compósitos convencional e impresso e suas aplicações |
| Beneficiário: | Éder Tadeu Gomes Cavalheiro |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |