Síntese de poliésteres a partir de glicerina e diácidos / Polyester synthesis from glycerin and diacids

No processo de produção de biodiesel há geração de quantidade relevante de glicerina bruta que ainda não possui destino definido. No presente trabalho propõe-se o desenvolvimento de poliésteres pela policondensação da glicerina com os diácidos como: ácidos oxálico, maleico, adípico e suas misturas a fim de verificar a viabilidade técnica de sua produção. A escolha do ácido oxálico como reagente se justifica pela sua potencialidade de mitigar de forma sustentável a emissão de CO2 para a atmosfera. Foram estudadas algumas das principais condições de síntese tais como a estequiometria e a quantidade de catalisador. Os materiais obtidos foram analisados por RMN, Cromatografia de Camada Delgada, FTIR, Índice de acidez, Índice de hidroxilas e GPC. Os resultados das últimas três técnicas mostraram que foram obtidos poliésteres com massa molar (Mn) até 15000 g/mol e com polidispersão variando de 1,05 a 3,3, e que o ácido oxálico, apesar de não formar polímero, pode participar numa mistura para controlar o peso molecular do poliéster

TREATMENT OF TANNERY EFFLUENTS FROM ADSORTION IN CHITOSAN SUBMITTED TO IONIC LIQUID TREATMENT

Initially, we performed the synthesis and characterization of sec-butylammonium acetate IL and chitosan activation with it. Afterwards, we used the activated chitosan to carry out the adsorption of chromium VI, which is the main metallic ion present in tannery effluents. The influence of the adsorbent storage time, adsorbent amount, test time, pH and temperature were analyzed. The storage time indicated low influence on the treatment and on the quality of the adsorbent; however, drying after the impregnation process gave the material greater adsorption capacity. The adsorption time was 1 hour, the ideal amount of 1.00 g and the temperature 25 ° C. Regarding pH, no significant changes were observed in the amount adsorbed between 2 and 4.5. These previously determined conditions were used for the treatment of the tannery effluent, verifying the efficiency of chromium VI concentration reduction

Preliminary in vitro and ex vivo evaluation of afzelin, kaempferitrin and pterogynoside action over free radicals and reactive oxygen species

Biological activities of flavonoids have been extensively reviewed in literature. The biochemical profile of afzelin, kaempferitrin, and pterogynoside acting on reactive oxygen species was investigated in this paper. The flavonoids were able to act as scavengers of the superoxide anion, hypochlorous acid and taurine chloramine. Although flavonoids are naturally occurring substances in plants which antioxidant activities have been widely advertised as beneficial, afzelin, kaempferitrin, and pterogynoside were able to promote cytotoxic effect. In red blood cells this toxicity was enhanced, depending on flavonoids concentration, in the presence of hypochlorous acid, but reduced in the presence of 2,20 -azo-bis(2-amidinopropane) free radical. These flavonoids had also promoted the death of neutrophils, which was exacerbated when the oxidative burst was initiated by phorbol miristate acetate. Therefore, despite their well-known scavenging action toward free radicals and oxidants, these compounds could be very harmful to living organisms through their action over erythrocytes and neutrophils