No abstract

No abstract

Polypropylene films (PP) surface treated by corona discharge in air was analyzed to verify the changes on surface composition. The presence of oxidized polar groups on the film surface, mainly, C=O, C-O and COH, was confirmed by infrared spectroscopy (FTIR/ATR) and atomic force microscopy (AFM) revealed a dramatic change in the morphology and provided qualitative results of the chemical composition (new structures). Contact angle (q) of the PP films decreased after corona treatment indicating an increase in the wettability due to the polar groups formed. Extended treatment results of low molecular weight oxidized material into the surfaces and a smaller additional degree of modification in the wettability is obtained.

No abstract

R ESU M OA conversão de biomassas agroindustriais em bioetanol com consequente valorização de rejeitos e resíduos, tem sido objeto de estudos de várias pesquisas realizadas no Brasil e no mundo. Neste trabalho foi avaliada a potencialidade do uso da polpa e da casca da banana (Musa cavendishii ), tanto in natura como previamente hidrolisada por ácido e enzimas, como substrato da fermentação alcoólica. Os rendimentos médios em bioetanol (em base úmida de biomassa) obtidos com a polpa (0,48 ± 0,05 g g -1) e com a casca (0,34 ± 0,11 g g -1), ambos in natura, possibilitaram a eficiência do processo de conversão, da ordem de 95% do rendimento teórico. A produtividade máxima alcançada em bioetanol foi de 3,0 ± 0,7 g L -1 h -1 com o uso da polpa e de 1,32 ± 0,03 g L -1 h -1 com a casca. Nas condições operacionais avaliadas o pretratamento dos resíduos com ácido sulfúrico não é recomendado para a produção de bioetanol. Palavras-chave: bioálcool, biocombustíveis, resíduos agrícolasAlternative energy from biomass: Bioethanol from banana pulp and peels A B ST R A C T The conversion of agroindustrial biomasses in bioethanol with consequent enrichment of wastes has been the object of various research projects conducted in Brazil and around the world. This study evaluated the potential of the Musa cavendishii banana pulp and peels using in natural state and also waste previously hydrolyzed by acid and enzimes, as substrate of alcoholic fermentation. The mean bioethanol yields (on wet biomass base), obtained with the pulp (0.48 ± 0.05 g g -1) and with the peels (0.34 ± 0.11 g g -1), both in natural state, enabled a conversion process efficiency to the order of 95% of theoretical yield. Maximum value reached in bioethanol was 3.0 ± 0.7 g L -1 h -1 with pulp and 1.32 ± 0.03 g L -1 h -1 with peels. Under the evaluated operating conditions, the pre-treatment of wastes with sulfuric acid is not recommended for bioethanol production.