This study described the morphology, crystallinity, thermal and mechanical characterization of Polyamide 11 (PA11) porous film prepared by non-solvent induced phase separation (NIPS) method using formic acid (FA) as solvent. In addition, the miscibility of PA11/FA/H2O system was performed to generate a ternary phase diagram. The porous films morphology was investigated by Scanning Electronic Microscopy (SEM) analysis, the crystallinity by X-Ray Diffractometer (XRD) and thermal study by Differential Scanning Calorimetry (DSC). A cellulosic reinforcement was used in porous films and the stress-strain analysis was performance by Dynamic Mechanical Analysis (DMA). The porous films were prepared with polymer composition of 15, 20 and 25 wt%. The porous films showed different microstructure in function of polymer concentration. The 20 and 25 wt% porous films showed micropores structures with medium pores diameters between 0-10µm calculated by image analysis. The XRD analysis show predominance of α crystalline form of polymer at 20 and 25 wt% porous films. The degree of crystallinity increases with polymer concentration increase. The stress-strain analysis of porous films shows a proportional dependence of Young’s modulus with the increase of polymer concentration in each film.

Abstract This work consists of preparation of the Chitosan(CHI)/Collagen(COL) blends loaded with silver nanoparticles by method of evaporation of the solvent. This blends were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results obtained demonstrated that the mass ratio of CHI/COL was important for the maintenance of the collagen structure since in the ratio 3:1 (m/m of CHI/COL) decrease in the ratio between the peaks of 1235 cm-1 and 1450 cm-1, respectively. Moreover the silver nanoparticles added to the polymer matrix of the obtained chitosan had an average size of 25 nm confirmed by TEM for silver nanoparticle.

Abstract In the present work, the depolymerization of polyethylene terephthalate (PET) was performed by the method of glycolysis with ethylene glycol. The process was carried out using a factorial design in the Box-Behnken optimization model, using a response surface methodology (RSM) in which three factors (time, temperature and mass ratio of ethylene glycol) were studied in three levels of variation (- 1, 0, +1) with two replicates of the center point, totalizing 15 experiments for which the yield of bis (2-hydroxyethyl) terephthalate (BHET) monomers formed in the process was chosen as response. In parallel, the Arrhenius kinetic test was used to determine the apparent activation energy (Ea) for the 1-butyl-3-methylimidazole trichlorozincate ([Bmin]ZnCl3) - catalyst used in the depolymerization process. The products of glycolysis obtained were characterized by spectroscopic techniques (FTIR), (1 H and 13C NMR), thermal analyses (TGA) and (DSC) and Mass Spectrometry LC-MS/MS hybrid Quadrupole-Orbitrap.

Resumo Foram investigadas as propriedades térmicas e mecânicas de compósitos de polipropileno reciclado e virgem, reforçados com até 40% em peso de fibras de celulose (FC), bem como a morfologia da matriz polimérica. Para a obtenção dos dados, foram utilizadas as técnicas de Análise Témica Dinâmico-Mecânica (DMTA), Calorimetria Exploratória Diferencial (DSC) e Microscopia Eletrônica de Varredura (MEV). Os resultados mostraram que os compósitos de polipropileno reciclado,com percentagem de 30% FC e os compósitos de polipropileno virgem, com percentagem de 20% FC, tiveram um aumento significativo nos valores de módulo de armazenamento (E') e grau de cristalinidade (χc), indicando com isso uma resistência mecânica mais elevada. Já nas amostras com 40% FC, houve uma diminuição na rigidez do material. Estes resultados foram confirmados por MEV, onde observou-se a aglomeração das fibras de celulose na matriz. Não houve alteração nas temperaturas de transição vítrea (Tg) e fusão cristalina (Tm) dos compósitos produzidos.

Abstract The thermal and mechanical properties of composite recycled and virgin of polypropylene were investigated, reinforced with up to 40% by weight of cellulose fibers (FC), as well as the morphology of the polymer matrix. To obtain the data, techniques for Dynamic-Mechanical Thermal Analysis (DMTA) were used, Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM). The results showed that recycled polypropylene composites with a percentage of 30% FC and virgin polypropylene composites with a percentage of 20% FC had a significant increase in storage modulus values (E') and degree of crystallinity (χc), indicating a higher mechanical strength in these composites. Since the samples with 40% FC, there was a decrease in the stiffness of the material. These results were confirmed by the SEM, where noted agglomeration of the cellulose fibers in the matrix. There was no change in the glass transition temperature (Tg) and crystalline melting temperature (Tm) of the produced composite.

Neste trabalho foi desenvolvida uma nova metodologia de reciclagem química do poli(tereftalato de etileno) grau garrafa pós-consumo, PETpc, através da reação de despolimerização em meio alcalino (solução de hidróxido de sódio, NaOH, de 7,5 mol L-1 a 100 ºC) e como catalisador o tensoativo catiônico brometo de hexadeciltrimetrilamônio, CTAB (1 × 10-2 mol L-1). A presença de CTAB aumentou o rendimento da reação em cerca de 85% e reduziu o tempo reacional de 6 para 2 h, quando utilizado em mistura NaOH/CTAB na proporção de 4:1 (% v/v) com 2 g de PETpc. O produto final, o monômero ácido tereftálico, TPA, foi caracterizado por análise termogravimétrica, calorimetria diferencial varredura, espectroscopia na região do infravermelho com transformada de Fourier e espectrometria de massas. Os resultados foram comparados com os da matéria-prima, PETpc. Além disso, o catalisador CTAB permaneceu no meio reacional (fase aquosa), sem interferir no processo de purificação do TPA.

In this work, a new analytical methodology has been developed for the chemical recycling of post-consumption bottle-grade poly(ethylene terephthalate), PETpc through depolymerization reaction in alkaline solution (NaOH solution of 7.5 mol L-1 at 100 ºC), using the surfactant cetyl trimethyl ammonium bromide (CTAB, 1 × 10-2 mol L-1) as catalyst. The presence of CTAB increased the reaction performance by ca. 85%, while the reaction time was decreased from 6 to 2 h when the mixture NaOH/CTAB was used in a proportion of 4:1 (% v/v) with 2 g of PETpc. The final product, the monomer terephthalic acid (TPA), was characterized by thermogravimetry analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy and mass spectrometry. The results were compared with those for the raw material, PETpc. Furthermore, the catalyst CTAB remained in the alkaline environment (aqueous phase), without interfering with the TPA purification process.