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Oriented b-phase films were obtained by utilizing two different techniques: conventional uniaxial drawing at 80 8C of predominantly a-phase films, and by drawing almost exclusively b-phase films obtained by crystallization at 60 8C from dimethylformamide (DMF) solution with subsequent pressing. Wide angle X-ray diffraction (WAXD) and pole figure plots showed that with the conventional drawing technique films oriented at a ratio (R) of 5 still contained about 20% of phase a, a crystallinity degree of 40% and bphase crystallographic c-axis orientation factor of 0.655. Drawing at 90 8C and with R ¼ 4 of originally b-phase films results in exclusively b-phase films with crystallinity degree of 45% and orientation factor of 0.885. Crystalline phase, crystallinity degree, and crystallographic c-axis orientation factor of both phases were also determined for aphase oriented films obtained by drawing a-phase films at 140 8C. For films drawn at 140 8C the a to b phase transition drops to about 22%. Reduction in crystallinity degree with increasing R is more pronounced at draw temperature of 140 8C compared with 80 8C. Moreover, for both phases the c-axis orientation parallel to the draw direction is higher at draw temperature of 140 8C than at 80 8C.

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Resumo: Este artigo tem a intenção de divulgar e apresentar a inserção da área ou da cadeia produtiva de Compósitos Poliméricos com Fibras Vegetais Naturais dentro do contexto do Projeto Fênix Amazônico. Duas frentes de pesquisa e desenvolvimento na área de compósitos de polímeros com fibras naturais vegetais são propostas: uma que trabalharia com sistemas de produção com maquinário relativamente barato e simples, para que as comunidades rurais da Amazônia pudessem absorver tal tecnologia; uma outra frente para desenvolver materiais compósitos com tecnologia de fabricação mais avançada. Deste modo esperamos despertar o interesse da comunidade científica e tecnológica das mais diversas áreas em colaborar com o desenvolvimento de novas tecnologias que possam ser utilizadas para a recuperação de áreas degradadas da Amazônia. Palavras-chave: Compósitos poliméricos, fibras vegetais naturais, termoplástico/madeira, biodiversidade, Floresta Amazônica, parceria. Development of Polymeric Composites with Natural Fibers: A Contribution to the Sustainability of AmazonAbstract: This paper presents the research on Polymeric Composites with Natural Fibers in the Amazon Fenix Project. Two research and development fields based on polymeric composites with natural vegetable fibers are proposed: the first one considers production systems with simple, cheap machinery to facilitate technology assimilation by rural communities in the Amazon; the second one aims at developing composite materials with advanced production technology. It is hoped to raise awareness for scientific and technological development for the recovery of degraded areas in Amazon.

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Electrospun nanocomposites of poly(e-caprolactone) (PCL) incorporated with PCL-grafted cellulose nanocrystals (PCL-g-CNC) were produced. PCL chains were grafted from cellulose nanocrystals (CNC) surface by ring-opening polymerization. Grafting was confirmed by infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA). The resulting PCL-g-CNC were then incorporated into a PCL matrix at various loadings. Homogeneous nanofibers with average diameter decreasing with the addition of PCL-g-CNC were observed by scanning electron microscopy (SEM). PCL-g-CNC domains incorporated into the PCL matrix were visualized by transmission electron microscopy (TEM). Thermal and mechanical properties of the mats were analyzed by differential scanning calorimetry (DSC), TGA and dynamic mechanical analysis (DMA). The addition of PCL-g-CNC into the PCL matrix caused changes in the thermal behavior and crystallinity of the electrospun fibers. Significant improvements in Young's modulus and in strain at break with increasing PCL-g-CNC loadings were found. These results highlighted the great potential of cellulose nanocrystals as a reinforcement phase in electrospun PCL mats, which can be used as biomedical materials. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43445.

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The influence of matrix viscosity and polarity on ethylene‐vinyl acetate copolymer (EVA) nanocomposites was studied. Five different EVA grades, with different melt flow indexes (MFIs) and/or vinyl acetate (VA) contents, were mixed with two montmorillonite (MMT) nanoclays: pristine and modified with a polar surfactant, producing 75/25 w/w% masterbatches which were subsequently diluted in the EVA matrix to obtain 5 wt% MMT nanocomposites. Although the same VA content, WAXS results, rheological measurements and TEM analysis showed that the lower the EVA viscosity, the greater the tendency to obtain exfoliated and well dispersed nanocomposites with the organically modified clay. On the other hand, the high viscosity EVA nanocomposites showed that the (001) organoclay diffraction peak was shifted to higher values of 2θ, suggesting lamellae collapsing. TGA and FTIR measurements were used to probe the thermal degradation of organoclay; furthermore, it was not possible to identify, by the techniques used, any reaction between the VA groups and hydroxyl surfactant groups. Thus, it was inferred that the organic surfactant was removed (or ejected) from the clay galleries as a consequence of huge shear tensions developed during processing of the masterbatches/nanocomposites with high viscosity EVA matrices. Copyright © 2009 John Wiley & Sons, Ltd.