Avaliação de sistemas lipidicos nanoestruturados utilizados como estratégia para melhorar as propriedades biofarmaceuticas do praziquantel no tratamento da esquistossomose

Pós-graduação em Nanotecnologia Farmacêutica - FCFAR

A qualidade de placas de circuito impresso confeccionadas a partir de poliestireno reciclado

Pós-graduação em Engenharia Mecânica - FEG

Processamento e caracterização de compósito fibra de sisal/resina epóxi via RTM

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento e caracterização de compósitos de fibras naturais modificadas e híbridos: fibras da coroa do abacaxi/polipropileno e fibras da coroa do abacaxi/fibras de vidro/polipropileno

The concern with the environment preservation has done with that researchers as well as industries invest in the search for materials that come from renewable sources. Natural fibers, because they are ecologically correct and have low cost, have been studied as a possible substitute, even if partial, of synthetic fibers in the development of polymeric composites. In this context, the hybrid composites (natural/synthetic) increase considerably the range of application of natural composites. The auto industry, in its constant quest for good mechanical properties materials which are developed with sustainability, has in composites with hybrid reinforcement a very viable alternative. In the present work, the nature Crown pineapple fibers and nature Crown pineapple fibers treated with alkaline solution were studied in order to evaluate the influence of chemical treatment in its properties. For this techniques were used x-ray diffractometry, Thermogravimetry and Infrared Spectroscopy (FTIR). Composites have been developed using polypropylene, reinforced with pineapple fibers and pineapple fibers hybrids/glass fibres, both with levels of 5 and 10%. These composites were analyzed by Thermogravimetry techniques and tested by traction. The realization of this work indicated that although the chemical treatment did not affect the thermal stability of the fibers, caused an increase in crystallinity index fibers and decreased its hydrophilic. The tests performed on composite indicated that the composites process was suitable because it provided good dispersion of the polymer matrix. The addition of natural fibers from the pineapple's Crown, in a proportion of 10%, provided the greatest increase in modulus of elasticity (27%) when compared to the pure polymer

Reciclagem de poliestireno expandido: compósito com fibras de algodão para a confecção de placas de circuito impresso

In this work polymeric composites reinforced with cotton fibers, from the textile industry, were developed in order to manufacture printed circuit boards. It was used expanded polystyrene (EPS) as a thermoplastic matrix by melting it. For the obtention of 10% and 15% of fiber volume fraction in cotton fibers composites, it was used wasted cotton fibers as an incentive of recycling and reusing of the domestic and industrial wastes as well as for Expanded Polystyrene(EPS). The mechanical properties of the composites were evaluated by tensile and flexural strength from standardized test methods. Composites were characterized by a Scanning Electron Microscopy (SEM), Thermogravimetry (TG/DTG), Differential Scanning Calorimetry (DSC) and dielectric analysis. The analysis of the results showed that fiber in the composite directly influenced in the thermal and mechanical properties

Reciclagem de poliestireno expandido: compósito com fibras de sisal para confecção de placas de circuito impresso

In this work polystyrene composites reinforced with recycled sisal fibers were processed, in order to apply in the manufacture of printed circuit boards. A thermoplastic matrix of recycled polystyrene was used, this material came from waste expanded polystyrene (EPS) used in appliance's packages. Composites were prepared with 15% and 25% of sisal fibers. To obtain the composites, wasted EPS and natural sisal fibers were chosen, to encourage recycling and reuse of household waste and also the use of renewable resources. The composites were analyzed by standard tensile and flexural test, in order to verify the mechanical properties of the material. The characterization of the composite was done by scanning electron microscopy (SEM) , thermogravimetry (TGA / DTG) , differential scanning calorimetry (DSC) and dielectric analysis . The analysis of the results showed that the percentage of fibers in the composite influences directly the thermal and mechanical properties. Plates with a lower percentage of fibers showed superior properties at a higher percentage. The composite material obtained is easy to process and it's use is feasible for the confection of printed circuit boards, considering it's mechanical, thermal and insulative properties

Comportamentos, térmico e mecânico, de compósitos de polipropileno e resíduo da hidrólise enzimática do bagaço de cana de açúcar

Pós-graduação em Engenharia Mecânica - FEG

Obtenção e caracterização térmica de compósitos nanoestruturados de resina fenol-furfurílica/CNT

Pós-graduação em Engenharia Mecânica - FEG

Quantificação eletroquímica de analitos de interesse ambiental e biológico, empregando novos materiais preparados a partir de silsesquioxanos funcionalizados

Pós-graduação em Ciência dos Materiais - FEIS

Estudo da cinética de degradação da resina benzoxazina e seus compósitos nanoestruturados

The benzoxaxine resin is a new class of thermoset phenolic resin, which is presenting, in the lasts decades, a great application in the aircraft industry due mainly to its excellent mechanical and thermal properties. This resin associates the mechanical properties of epoxy resin with the thermal and flame retardant properties of phenolic resin. In this context, they are considered polymers of high performance and they are excellent candidates to replace the current thermoset matrices used in the processing of high performance composites. Thus, in this study nanostructured composites Benzoxazine/CNT were produced at different concentrations of functionalized and non-functionalized CNT (0,1%; 0,5% and 1,0% w/w). The thermal stability of the benzoxazine resin and its nanostructured composites was studied using thermogravimetry (TGA) and degradation kinetic model Ozawa-Wall-Flynn (O-W-F). The thermal characterization also included differential scanning calorimetry (DSC) and dynamic-mechanical analysis, infrared spectroscopy with Fourier transform (FTIR) and scanning electron microscopy (SEM).The introduction of non-functionalized CNT at low concentrations resulted in nanostructured composites with better thermal properties in relation to the neat resin. For all cases, however, the dispersion of CNT in the matrix was ineffective

Estudo da influência de tratamentos químicos da fibra de sisal nas propriedades de compósitos com borracha nitrílica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização mecânica e térmica da borracha natural formulada e vulcanizada dos clones: GT 1, IAN 873, PB 235 e RRIM 600

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ilustração da influência da razão de aquecimento nos resultados de termogravimetria

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermo-gravimetric analysis (TGA) after different exposures of high density polyethylene (HDPE) and poly vinyl chloride (PVC) geomembranes

This paper presents the results of thermogravimetric analysis (TGA) tests in PVC (1.0; 2.0 mm) and HDPE (0.8; 2.5 mm) geomembranes exposed to weathering and leachate after 30 months. The aim of this paper is the comparison of fresh and exposed samples to assess the degradation process concerning the total loss of mass of geomembranes. The exposure was conducted in accordance with the recommendations of ASTM standards. The TGA tests were carried out according to ASTM D6370 and E2105. Results show, for instance, that for PVC geomembrane the largest reductions of plasticizers occurred for samples exposed to weathering. The loss of plasticizers after the exposure contributed to the decrease of deformation and consequent increase in stiffness. TGA tests shows to be a valuable tool to control the quality of the materials. © 2012 ejge.

Estudo das propriedades de eletrocatalisadores de Pt-Ru nanoparticulados preparados via microemulsão para oxidação de metanol

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)