Abstract The use of polymer blends and composites based on fossil-based and bio-based polymers has become an important environmentally protective alternative for common use and disposable plastics applications such as packaging, bottles and trays. The disposal of these more degradable products, however, may also harm the environment and, therefore, recycling these systems becomes relevant. Recycling involves reprocessing which can significantly change the morphology and properties of polymeric products. Therefore, this study deals with the effects of reprocessing cycles on the properties and morphology of blends and nanocomposites based on fossil and bio-based polymers. The systems investigated were: a) neat polypropylene (PP), b) a polypropylene/poly(3-hydroxybutyrate) (PP/PHB) blend and c) PP/PHB/organoclay nanocomposite compatibilized with polypropylene-g-maleic anhydride (PP-g-MA) and erucamide. These materials were submitted to up to seven extrusion cycles in a single screw extruder operating at 60 rpm. Samples were taken after the first, third, fifth and seventh extrusion cycles and their tensile properties and morphology were determined. Scanning electron microscopy indicated that two phases were observed in the blend which showed spherical PHB domains. The addition of clay, PP-g-MA and erucamide improved the adhesion between the nanocomposites components. X-ray diffraction analysis showed that crystallinity tended to increase with the number of reprocessing cycles for all systems investigated up to the fifth cycle and then tended to decrease. A 10% crystallinity increase was observed for neat PP in the fifth cycle. In general, the tensile properties of all systems decreased with reprocessing and the highest losses were observed for the PP/PHB blend after seven processing cycles with 50% and 37% decreases in stress at break and elastic modulus, respectively. Impact strength of the PP matrix and of the PP/PHB blend tended to decrease with reprocessing, except for the nanocomposite which showed a slight increase especially after the seventh processing cycle in which an 18% increase in impact strength was observed.

RESUMO Objetivo: conhecer experiências pedagógicas inovadoras desenvolvidas por docentes no ensino da enfermagem psiquiátrica e saúde mental nos cursos de graduação em enfermagem de universidades públicas do estado do Rio de Janeiro. Método: embasada por abordagem etnometodológica, foram realizadas entrevistas individuais semiestruturadas e análise documental, segundo a análise de conteúdo. Resultados: apesar da heterogeneidade na distribuição curricular dos saberes da enfermagem psiquiátrica e saúde mental, os temas lecionados apresentam semelhanças. As percepções de inovação estão principalmente relacionadas a práticas interdisciplinares e uso de tecnologias de ensino, relacionais, de cuidado. As práticas inovadoras de ensino estão voltadas à utilização de metodologias ativas e atividades colaborativas. Considerações finais: inovar o ensino demanda criar estratégias para ensinar gente a cuidar de gente, valorizando a singularidade humana. A participação dos estudantes nos serviços de saúde é a chave para o diálogo entre o conhecimento produzido na academia e o mobilizado nos serviços de saúde.

ABSTRACT Objective: to know innovative pedagogical experiences developed by professors in the teaching of psychiatric nursing and mental health in undergraduate nursing courses at public universities in Rio de Janeiro State. Method: based on an ethnomethodological approach, individual semi-structured interviews and document analysis were carried out according to content analysis. Results: despite the heterogeneity in the curriculum distribution of psychiatric nursing’s and mental health’s knowledge, the themes taught have similarities. The perceptions of innovation are mainly related to interdisciplinary practices and teaching, relational, and care technologies. Innovative teaching practices are focused on the use of active methodologies and collaborative activities. Final considerations: innovating teaching requires creating strategies to teach people how to care for people, valuing human uniqueness. Student participation in health services is the key to the dialogue between knowledge produced in academia and that mobilized in health services.

RESUMEN Objetivo: conocer experiencias pedagógicas innovadoras desarrolladas por docentes en la enseñanza de enfermería psiquiátrica y salud mental en cursos de pregrado en enfermería en universidades públicas del estado de Rio de Janeiro. Método: con base en un enfoque etnometodológico, se realizaron entrevistas individuales semiestructuradas y análisis de documentos, de acuerdo con el análisis de contenido. Resultados: a pesar de la heterogeneidad en la distribución curricular del conocimiento de enfermería psiquiátrica y salud mental, los temas enseñados presentan similitudes. Las percepciones de innovación están relacionadas principalmente con las prácticas interdisciplinarias y el uso de tecnologías docentes, relacionales y asistenciales. Las prácticas de enseñanza innovadoras se centran en el uso de metodologías activas y actividades colaborativas. Consideraciones finales: innovar en la enseñanza requiere crear estrategias para enseñar a las personas cómo cuidar de las personas, valorando la singularidad humana. La participación de los estudiantes en los servicios de salud es clave para el diálogo entre el conocimiento producido en la academia y el movilizado en los servicios de salud.

The population increase, urbanization and climatic change adversely affect the agricultural production have prompted actions to improve the means of production without affecting the environment. One of the actions to make the production of food more efficient and sustainable is the use of plastics in protection of crops, soils and packaging, for example. Therefore, the aim of this work was to develop flat extruded mulch films of poly (butylene adipate-co-terephthalate)/2.5 and 5.0% sugar cane residue/2.0% carnauba wax for application in soil cover and characterize them as to their chemical structure, morphology and transmittance. The FTIR results suggest that there was no chemical interaction between the components of the mulch films. SEM images and optical microscopy showed that the polymer matrix was able to cover sugarcane residues and that the carnauba wax dispersed well in the PBAT matrix. In addition, carnauba wax addition increased the transmittance of these mulch films.

Abstract Studies about in vitro biodegradation of polymers have grown considerably due to the wide application of biodegradable polymers in biomedical areas. The objective of this study was to prepare bionanocomposites films of PHB, PEG, and organoclays by solution intercalation, and to evaluate the morphology, structure, hydrolytic degradation through FTIR and the calculation of carbonyl content. The results showed that bionanocomposites displayed intermediated dispersion of the filler, the polymer chains were intercalated into the organoclay layers and was observed some degree of exfoliation. There was an influence of PEG and of the clay on the degradation of the polymer, this fact was observed due to the decrease in the intensity of PHB carbonyl band in the region around 1275 cm-1, affecting the amorphous and crystalline regions of the polymer. This reduction can be associated with the increase in hydrophilicity of the polymer caused by the presence of the PEG and clay, suggesting the possibility of increasing the biodegradability of the pure polymer. In future research, there will be made characterizations to know if these materials can be used in medical devices.

ABSTRACT During the last decades, a lot of research work focused on several biodegradable and biosourced polyesters for the purpose of reducing the non-degradable polymer wastes. These polyesters are particularly considered to be promising polymers for biomedical applications and short life-time products like packaging. As these packagings are rapidly discarded, especially the food ones, their accumulation becomes a serious environmental problem. In order to replace these materials with new ones that do not harm the environment, several studies are being carried out about these materials. However, it presents some limitations as its thermal instability in the molten state and high cost of production, being the incorporation of clay to the polymer matrix, forming bionanocomposites, a viable alternative since it improves the mechanical and thermal properties of the material when compared to the pure polymer, and may or may not reduce the total cost of production. Among commercially-available polyesters, polyhydroxyalkanoates (PHAs) are produced by various bacteria and known to be fully biodegradable. The aim of this study was to develop and to characterize bionanocomposites produced from the polymer matrix of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) - PHBV and natural vermiculite and organoclay. The melt intercalation technique was used for obtaining systems in the form of films. The FTIR results unveiled changes in the bionanocomposites structure with the addition of the clay, verifying the incorporation and overlap of bands of both the natural clay and the quaternary ammonium salt. Through the XRD technique, it was observed a greater disorganization in the systems compared to the pure polymer, suggesting a structure of a microcomposite for the systems with natural clay and tending to a greater exfoliation for the systems with organoclay vermiculite. From the micrographs by MO and MEV, the films presented a small number of clusters for the natural systems and a more uniform structure for the organophilic systems, thus corroborating with the XRD. In this way, it was evidenced that the systems with organoclay were the ones that presented better against the characteristics desired for its possible industrial application. Thus, elaborated bionanocomposites may be an alternative to the substitution of synthetic polymers in the industry, for example, in food packaging.