For the purpose of renewable materials applications, Curauá fiber treated with 5% sodium hydroxide was added to high-density biopolyethylene, using an entirely Brazilian raw material of sugarcane ethanol. Polyethylene grafted with maleic anhydride was used as a compatibilizer. With the addition of curauá fiber, the crystallinity was reduced, possibly due to interactions in the crystalline matrix. A positive thermal resistance effect was observed for the maximum degradation temperatures of the biocomposites. When curauá fiber was added (5% by weight), the morphology showed interfacial adhesion, greater energy storage and damping capacity. Although curauá fiber additions did not affect the yield strength of high-density bio polyethylene, its fracture toughness improved. With the addition of curauá fiber (5% by weight), the fracture strain was greatly reduced to about 52%, the impact strength was also reduced, suggesting a reinforcing effect. Concomitantly, the modulus and the maximum bending stress, as well as the Shore D hardness of the curauá fiber biocomposites (at 3 and 5% by weight), were improved. Two important aspects of product viability were achieved. First, there was no change in processability and, second, with the addition of small amounts of curauá fiber, there was a gain in the specific properties of the biopolymer. The resulting synergies can help ensure more sustainable and environmentally friendly manufacturing of automotive products.

Biocomposites are defined as eco-friendly materials from an environmental point of view. Because of the importance of this class of materials, their study is important, especially in moist and heated conditions. In this sense, this work aims to evaluate the transient behavior of moisture absorption and mechanical performance of biocomposites composed of a matrix of high-density biopolyethylene (originated from ethanol produced from sugarcane) filled with curauá vegetable fiber and organophilic montmorillonite clay. For this purpose, dry biocomposites filled with organophilic montmorillonite clay and curauá fiber (1, 3, and 5 wt.%) were prepared using a hand lay-up technique and subjected to moisture absorption and mechanical (flexural and impact tests) characterizations at different times. The experiments were carried out at water bath temperatures of 30 °C and 70 °C. The results have proven the strong influence of chemical composition and temperature on the moisture absorption behavior of biocomposites across time. For a higher percentage of reinforcement on the polymeric matrix, a higher moisture migration rate was verified, reaching a higher hygroscopic equilibrium condition at 16.9% for 5 wt.% of curauá fiber and 10.25% for 5 wt.% of montmorillonite clay particles. In contrast, the mechanical properties of all of the biocomposites were strongly reduced with an increasing moisture content, especially at higher fiber content and water bath temperature conditions. The innovative aspects of this research are related to the study of a new material and its transient mechanical behavior in dry and wet conditions.

Nanocompósitos foram preparados utilizando argila montmorilonita organofílica, como reforço, a matriz termoplástica de Polietileno de Alta Densidade (PEAD). Os nanocompósitos foram preparados pelo método de mistura no estado fundido convencional, com diferentes frações do reforço (1 e 2,5%) em massa, em seguida moldados por injeção. As caracterizações da argila organofílica foram feitas por fluorescência de Raios X (FRX), difração de Raios X (DRX), termogravimetria (TG e DTA) e espectroscopia na região do infravermelho (FTIR). A caracterização dos nanocompósitos através microscopia eletrônica de transmissão (MET) e propriedades mecânicas de tração. Através dos resultados mecânicos de tração, a concentração da argila, a dispersão e sua interação com a matriz, influenciam diretamente na resistência a tração dos corpos de prova. As imagens de MET revelaram as morfologias dos nanocompósitos, apresentando estruturas parcialmente esfoliadas com predominância de alguns aglomerados.

With the growing human awareness of trying to reduce the environmental impact in today’s world, the development of new sustainably based materials has been the increasing focus of industry and academia. Biocomposites are environmentally friendly materials produced from raw materials synthesized from renewable sources. In this sense, this work aims to characterize and evaluate the mechanical and thermal performances of biocomposites manufactured from a thermoplastic matrix of high-density bioethylene and obtained from ethanol produced from sugarcane and reinforced with organophilic montmorillonite clay. For this, polyethylene grafted with maleic anhydride (PE-g-MA) was used as a compatibilizer. Dry biocomposites with 1, 3, and 5% organophilic montmorillonite clay, by weight, were subjected to structural (FTIR and DRX), thermal (DSC), thermogravimetric (TG/DTG), thermodynamic–mechanical (DMA), morphological (SEM and MET), and mechanical (tensile, flexural, impact, and shore D hardness tests) characterizations. The DMA experiments were carried out within the viscoelastic region of the polymer. From the obtained results, we notice that, in general, there was an increase in the properties of high-density biopolyethylene (B-HDPE) (without compromising its processability), and therefore, the automotive application of biocomposites compatible with PE-g-MA, containing low levels of organophilic montmorillonite clay, is recommended.

A agricultura tem papel importante na entrega de alimentos e outros bens destinados aos próprios agricultores e aos mercados, tendo uma grande participação econômica no Brasil, vale ressaltar que o modelo agrícola passou por transformações e trouxe consigo a preocupação ambiental. Assim, ante o exposto o presente artigo busca analisar o nível de sustentabilidade da produção agrícola em Mesorregiões diferentes no Estado da Paraíba. Quanto aos procedimentos metodológicos, o estudo foi realizado com produtores do município de Pombal, mesorregião do Sertão e com produtores do município de Lagoa Seca, mesorregião do Agreste, no Estado da Paraíba, a coleta de dados foi feita mediante questionários aplicados diretamente aos produtores e com base nestes dados foram calculados os índices de qualidade de vida, capital social e ambiente, para então calcular o índice de sustentabilidade e avaliar o nível de sustentabilidade nas duas áreas em estudo. Os resultados da pesquisa revelam que as duas mesorregiões atingiram o nível médio da sustentabilidade. Ao comparar os índices, ficou evidente que a qualidade de vida foi um indicador que contribuiu de maneira equitativa nas duas áreas em estudo, já o capital social apresentou-se mais forte na mesorregião do sertão, já o indicador ambiental apresentou-se em números maiores na mesorregião do agreste.