Tratamentos de fibras de carnaúba [copernicia prunífera (miller) h. e. moore] para o desenvolvimento de compósito biodegradável com matriz de polihidroxibutirato

The use of raw materials from renewable sources for production of materials has been the subject of several studies and researches, because of its potential to substitute petrochemical-based materials. The addition of natural fibers to polymers represents an alternative in the partial or total replacement of glass fibers in composites. In this work, carnauba leaf fibers were used in the production of biodegradable composites with polyhydroxybutyrate (PHB) matrix. To improve the interfacial properties fiber / matrix were studied four chemical treatments to the fibers..The effect of the different chemical treatments on the morphological, physical, chemical and mechanical properties of the fibers and composites were investigated by scanning electron microscopy (SEM), infrared spectroscopy, X-ray diffraction, tensile and flexural tests, dynamic mechanical analysis (DMA), thermogravimetry (TGA) and diferential scanning calorimetry (DSC). The results of tensile tests indicated an increase in tensile strength of the composites after the chemical treatment of the fibers, with best results for the hydrogen peroxide treated fibers, even though the tensile strength of fibers was slightly reduced. This suggests a better interaction fiber/matrix which was also observed by SEM fractographs. The glass transition temperature (Tg) was reduced for all composites compared to the pure polymer which can be attributed to the absorption of solvents, moisture and other low molecular weight molecules by the fibers

Uso sustentável da Copernicia prunifera (Miller) H. E Moore no semiárido potiguar: valorização de saberes e conservação dos recursos genéticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Cuidado de si e hermenêutica do sujeito em Michael Foucault

The work, here present, has as its objective to present in a clear and distinct manner the object of study of Michel Foucault in his last years of teaching at the College de France, namely, the care of the self. We present the care of the self in its birth, in its origin, from the character Socrates and its development until the beginning of the Christian age. With a keen eye, we present Foucault with a work of return and rescue of the care of the self to the personal and academic discussions; we propose, from the self care, to the contemporary subject a problematization of their life so that from this questioning he creates for herself ways of life that are coherence, knowledge and care with which he has of must particular, his himself. Passing by the sources that served as the source of study for Foucault to sketch the birth of care of the self, we design the form with which Foucault has dealt with the documents that speak of the care of self. We present Socrates as one who by excellence ensures that the other will give birth to the forms of knowledge and care of the self or, in other words, we present the care of the self socratic-foucauldian as a constant worry of the other to pay attention to ways in which he conducts her life, it creates for themselves ways of being and, therefore, creates ethics of existence. We present, finally, the care of the self as the cause of continuous immanence of modes of subjectivation of the subject that configure themselves in a non-accepting a determined essence, but a continually updated form . The care of the self leads to a single relationship and educator of modes of subjectivation of the subject; he creates, on the dynamics of temporality, ethical ways of living, which are sustained by an internal coherence of the subject with herself; he admits no stationary nature in the training of the subject, always wants a more beautiful work of himself; he is not isolation, he needs and is made with the other. The care of the self is the principle and the telos of battles and conquests of the subject within his temporality and existence