Non-biodegradable single use packaging are a serious environmental problem as it generates large amounts of waste and is generally not recycled. These packages, especially those made of expanded polystyrene, can be replaced by thermoplastic starch foams. These foams have the advantage of being from renewable sources and biodegradable. However, this material is hydrophilic and becomes unusable when it is exposed to water. Hydrophobizing starch comes as an alternative to make the foams more resistant to contact with water. The purpose of the modification is to exchange starch hydroxyl groups for less polar groups such as silane groups. In this work, two silanes were used for starch silylation: 3-chloropropyl trimethoxysilane and Methyltrimethoxysilane. The foams were made using four materials: modified starch, gelatinized starch, polyvinyl alcohol and water. Results from water absorption tests and mechanical tests show that foams absorb less water and become more resistant with the addition of silylated starch.

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This work investigated the effect of thermal treatment in an autoclave on the chemical, physical, and morphological properties of lignocellulosic fibers from açaí (Euterpe oleracea Mart), and the behavior of this treated fiber in polypropylene (PP) matrix composites with polypropylene-graft-maleic anhydride (PPgMA) as the coupling agent. The treated and untreated fibers were characterized by chemical composition, x-ray diffraction, FTIR spectroscopy, and thermogravimetry, scanning electron microscopy and tensile tests were carried out for the composites. The results showed that the thermal treatment modified the hemicellulose and lignin content and increased the fiber surface roughness, without compromising the thermal stability. The composite prepared with thermally treated fibers and PPgMA exhibited an increase in tensile strength but a reduction in tensile modulus. In conclusion, the thermal treatment of vegetable fiber is a promising technique for improving the performance of composites.

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In this work, a bio-based adhesive is prepared from Protium heptaphyllum resin. The resin is first characterized by 1 H and 13 C nuclear magnetic resonance spectroscopy and the bioadhesive is then prepared using a simple mixture of the resin with linseed oil, catalyzed by cobalt octanoate, to induce crosslinking. The precursors and bioadhesive obtained are characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The NMR analysis shows the presence of groups of triterpenes, such as α-and β-amyrins, and diols, such as brein and maniladiol. Thermogravimetric analysis reveals that the resin has less thermal stability than the bioadhesive. Mechanical tests indicate that the bioadhesive has greater adhesion strength compared to the commercial adhesive, reaching an average stress at break of 7.66 and 0.113 MPa for the wood and carbon steel substrates, respectively. In conclusion, the bioadhesive can be used for the production of composites.