RESUMO As espécies de Arecaceae, conhecidas popularmente por palmeiras, além de se destacarem na paisagem amazônica, agregam valores econômico e social. O presente trabalho teve como objetivo analisar as características físico-químicas dos óleos extraídos de cinco variedades de frutos de pupunha (Bactris gasipaes Kunth). Para tanto, amostras de frutos de cinco matrizes provenientes de plantios foram coletadas no município de Cruzeiro do Sul, região do alto Juruá (74º0’ W a 72ºW e 7º05’ S a 9º40’ S) e foram determinados o teor de óleo, densidade, índice de refração, espectrofotometria e cromatografia em camada delgada. Os dados foram submetidos às análises de variância (ANOVA) e de regressão, cuja diferença entre as médias dos tratamentos foi testada por meio do teste de Tukey a 5% de significância, realizados com o auxílio do software RStudio Core Team, versão 3.6.3 e com pacote ExpDes.pt, car, stats e fBasics. Os resultados apontaram teores de óleo essencial de 24,29%, 24,28% para as matrizes 2 e 4 e abaixo de 8,1% para as matrizes 1,3 e 5. O índice de acidez variou de 1,26 a 5,22 mg NaOH/g de óleo, enquanto o índice de refração variou de 1,4510 a 1,4690. A análise de cromatografia em camada resultou em sete Rfs, sendo eles nas faixas 0,325; 0,45; 0,5; 0,6; 0,7; 0,8 e 1 para todos os óleos analisados, com curvas espectroscópicas apresentando diferenças significativas nas faixas de 320 a 540 nm, indicando diferentes grupos funcionais e/ou substâncias nos extrativos vegetais. De acordo com os resultados, o óleo essencial das amostras de frutos de pupunha (Bactris gasipaes) apresentou valores distintos e significativos para os cinco parâmetros físico-químicos avaliados, o que desperta a atenção para uma possível ocorrência de variabilidade genética no material estudado, mas sugerindo, ao mesmo tempo, que se amplie a investigação, com um maior tamanho amostral e se confirme uma alternativa de investimento em melhoramento genético.

ABSTRACT In addition to standing out in the Amazonian landscape, Arecaceae species, popularly known as palm trees, add economic and social values. The purpose of this paper was to analyze the physical and chemical characteristics of the oils extracted from five varieties of peach palm fruits (Bactris gasipaes). In order to achieve such purpose, fruit samples from five plantation matrices were collected in the municipality of Cruzeiro do Sul, in the upper Juruá region (74º0 ‘W at 72ºW and 7º05’ S at 9º40 ‘S). We determined the oil content, the density, the refractive index, the spectrophotometry, and the thin layer chromatography. The data were subjected to analyses of variance (ANOVA) and regression. The difference between the means of the treatment was tested with the Tukey test at 5% significance, performed with the aid of RStudio Core Team software, version 3.6.3 and with ExpDes.pt package, car, stats and fBasics. Our findings showed essential oil contents of 24.29%, 24.28% for matrices 2 and 4, and below 8.1% for matrices 1.3 and 5. The acidity index ranged from 1.26 to 5.22 mg NaOH / g oil, whereas the refractive index ranged from 1.4510 to 1.4690. The analysis of layer chromatography resulted in seven RFs, with the ranges 0.325; 0.45; 0.5; 0.6; 0.7; 0.8 and 1 for all oils analyzed. Spectroscopic curves showed significant differences in the ranges 320 to 540 nm, indicating different functional groups and/or substances in the extractives. According to the results, the essential oil from the samples of peach palm fruits (Bactris gasipaes) showed distinct and significant values for the five physical and chemical parameters evaluated, which calls attention to a possible occurrence of genetic variability in the material studied. The findings suggest that the investigation should be expanded with a larger sample size, and that an alternative investment in genetic improvement should be confirmed.

Abstract The non-isothermal decomposition kinetics of conductive polyaniline (PANI) and its derivatives, poly(o-methoxyaniline) (POMA) and poly(o-ethoxyaniline) (POEA), was investigated by thermogravimetric analysis (TGA), under inert and oxidative atmospheres, using Flynn-Wall-Ozawa’s approach to assess the kinetic parameters of the decomposition process. The order of reaction was found to be dependent on the degree of conversion indicating that both the early and the later stages of polymer degradation were next the zero or pseudo zero order kinetics, whereas the intermediate stages follow a first order kinetics. The activation energy was found to be dependent on both the degree of conversion and PANI derivative. Activation energy values vary from 125 to 250 kJ/mol, to decompositions carried out under nitrogen, and 75 to 120 kJ/mol to oxidative atmosphere. Parent PANI presented the best thermal stability and suggesting that thermal stability is also influenced by derivatization and type of atmosphere used.