Resumo: O PHB (Poli-3-hidroxibutirato) é um termoplástico biodegradável sintetizado por fermentação submersa a partir de matérias-primas renováveis. A utilização de fibras naturais tem sido pesquisada visando melhorar as propriedades e reduzir o custo do PHB. O objetivo deste trabalho foi o estudo das propriedades mecânicas (resistência à tração), térmicas (Análise termogravimétrica,TGA, e Calorimetria Exploratória Diferencial, DSC) e reológicas (torque em câmera de mistura e Índice de Fluidez) do PHB e de compósitos de PHB/pó de madeira processados e irradiados. Foram preparados compósitos com concentrações de PHB/pó de madeira de 90/10, 80/20 e 70/30 (m/m). Os materiais foram processados através das seguintes etapas de processamento: calandragem, fragmentação, extrusão, granulação, secagem e moldagem por injeção para confecção dos corpos de prova. A incorporação do pó de madeira aumentou o grau de cristalinidade e a temperatura de cristalização do polímero, e nos compósitos PHB/pó de madeira 80/20 e 70/30 a rigidez do material aumentou. A irradiação após o processamento (dose de 30 kGy) provocou aumento da rigidez do PHB puro e dos compósitos PHB/pó de madeira 90/10 e 80/20, embora outras propriedades tenham decrescido. O compósito PHB/pó de madeira 70/30 apresentou os melhores resultados em termos econômicos e de processamento. Palavras-chave: Poli-3-hidroxibutirato, compósitos PHB/pó de madeira, propriedades térmicas, propriedades mecânicas, irradiação, processamento. Study of Mechanical and Thermal Properties of the Polymer Poly-3-Hydroxybutyrate (PHB) and PHB/Wood Flour CompositesAbstract: PHB (Polyhydroxybutyrate) is a biodegradable thermoplastic synthesized by submerse fermentation of renewable raw materials. The use of natural fibers has been largely researched to improve PHB properties, as well as reducing its cost. The purpose of this work was the study of the mechanical, thermal properties and rheological analyses (torque in mixer camera and melt flow index) of processed and irradiated PHB, as well as PHB/wood flour composites. PHB/wood flour composites were prepared with PHB/wood relation of 90/10, 80/20 and 70/30 (w/w). Both pure PHB and composites were processed through the following steps: calendering, milling, extrusion, second milling, drying and injection molding to make test specimens. Mechanical properties (strength resistance) and thermo analyses (Thermogravimetric Analysis, TGA and Differential Scanning Calorimeter, DSC) tests were carried out. The introduction of the wood flour increased both polymer crystallinity and crystallization temperature. IntroduçãoNovos materiais compósitos estão sendo desenvolvidos, combinando-se matrizes termoplásticas e cargas reforçativas de origem lignocelulósicas. Devido à intensificação das questões ambientais, pesquisas envolvendo o emprego de polímeros biodegradáveis como substitutos dos polímeros sintéticos convencionais aumentaram nos últimos anos, assim como o uso de fibras naturais como reforço dos mesmos. As vantagens da utilização de reforços lign...

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The structure of aluminum monohydroxide resulting from synthesis by ammonium hydroxide with aluminum chloride (or aluminum nitrate, for example) by a sol-gel process, gives a purified and chemically inert material with many applications possibilities because of its great specific surface area. A pseudoboehmite is the choice in this project for adsorption/desorption of atenolol. The molecular interaction with the pseudoboehmite substrate was studied by FTIR (Infrared Spectroscopy), DSC (Scanning electron /TG Thermogravimetry), UV-vis (Ultraviolet-visible spectroscopy) and SEM (Scanning Electron Microscopy). The SEM characterization has been used to quantify the local structural surface for the correlations with the synthesis process; and the Spectroscopies and Thermogravimetric techniques were used for measurements of the adsorption/desorption concentrations of the drug in physiological solution. This procedure gives information to the chemistry and surface of these fine ceramics material that would be applied like excipient in medications to control the drug delivery and plasmatic concentrations in optimal conditions.

The production of confined or adsorbed drugs in inorganic matrix has been increasing in areas like material science and pharmaceutical due to the possibility of the production of nanoadsorbed or encapsulated molecules with new properties like chemical stability, enhancing solubility and controlled release, what implies in new applications of materials. In the present work, a nanocomposite of a fine ceramic material, pseudoboehmite, and acyclovir, was prepared. Pseudoboehmite is based on a monohydroxide aluminum oxide produced from a synthetic route using ammonium hydroxide and aluminum nitrate or chloride as precursors in the sol-gel process. These systems had been characterized by the following techniques: MEV, TG/DSC, FTIR and UV-vis. The exposition of the drug to the pseudoboehmite at the dissolution equipment was at 37°C and 100rpm for 30 minutes. With the purpose to observe the interaction of the drug with the adsorbent, it was obtained the concentration of the drug in the solution, before and after the adsorption, using the UV-vis spectroscopy technique. The acyclovir has increased its solubility in an HCl 0,1M solution, when the weight ratio of Pseudoboehmite: Acyclovir 1:1 was used.