No abstract

Optically transparent membranes from bacterial cellulose (BC)/polycaprolactone (PCL) have been prepared by impregnation of PCL acetone solution into dried BC membranes. UV-Vis measurements showed an increase on transparency in BC/PCL membrane when compared with pristine BC. The good transparency of the BC/PCL can be related to the presence of BC nanofibers associated with deposit of PCL nano-sized spherulites which are smaller than the wavelength of visible light and practically free of light scattering. XRD results show that cellulose type I structure is preserved inside the BC/PCL membrane, while the mechanical properties suggested indicated that PCL acts as a plasticizer for the BC membrane. The novel BC/PCL membrane could be used for preparation of fully biocompatible flexible display and biodegradable food packaging.

RESUMO Os processos relacionados com a produção de refeições para os consumidores são causadores de impactos para o meio ambiente. Este trabalho teve como objetivo identificar quais são as práticas de restaurantes brasileiros relacionadas com a temática da gestão ambiental e da sustentabilidade. Trata-se de um estudo de revisão sistemática de publicações no período de 2000 a 2015. Entre os resultados encontrados, destacam-se a geração de resíduos de alimentos no processo de produção e consumo das refeições, além de investigações sobre acondicionamento, reciclagem e destinação desses resíduos. São apresentadas também as temáticas de utilização de recursos (água e energia) e um panorama sobre a avaliação dos aspectos ambientais por meio da prática de certificação de restaurantes comerciais com selos de sustentabilidade. Estudos avaliativos dessa natureza são importantes para contribuir para o diagnóstico da realidade no segmento de produção de refeições e também para fomentar investigações futuras que apontem para a redução dos impactos ambientais nessa atividade.

No abstract

Polylactic acid is a polymer of great technological interest, whose excellent mechanical properties, thermal plasticity, and bioresorbability render it potentially useful for environmental applications, as a biodegradable plastic and as a biocompatible material in biomedicine. This article discusses the synthesis and characterization of poly-L-lactic acid, obtained through two synthetic routes: direct polycondensation reactions without organic solvents, and in a supercritical medium. Tin complexes were used as catalysts in both polymerization reactions. The polymers were characterized by 1 HNMR, IR, GPC, DSC, and TGA techniques. In vitro biocompatibility tests were performed with human alveolar bone osteoblasts and there were assessed cell adhesion, proliferation and viability. The poly condensation reaction proved to be an excellent synthetic route to produce PLA polymers with different molar mass. The formation of polymers from lactic acid monomer was confirmed through techniques utilized. It was observed that cell adhesion and viability was not disturbed by the presence of the polymer, although the proliferation rate was decreased when compared to control.