The influence of natural clay and organoclay vermiculite on the formation process of bionanocomposites with poly (3-hydroxybutyrate-co-3-hydroxyvalerate)

Abstract

During the last decades, a lot of research work focused on several biodegradable and biosourced polyesters for the purpose of reducing the non-degradable polymer wastes. These polyesters are particularly considered to be promising polymers for biomedical applications and short lifetime products like packaging. As these packagings are rapidly discarded, especially the food ones, their accumulation becomes a serious environmental problem. In order to replace these materials with new ones that do not harm the environment, several studies are being carried out about these materials. However, it presents some limitations as its thermal instability in the molten state and high cost of production, being the incorporation of clay to the polymer matrix, forming bionanocomposites, a viable alternative since it improves the mechanical and thermal properties of the material when compared to the pure polymer, and may or may not reduce the total cost of production. Among commercially-available polyesters, polyhydroxyalkanoates (PHAs) are produced by various bacteria and known to be fully biodegradable. The aim of this study was to develop and to characterize bionanocomposites produced from the polymer matrix of poly (3-hydroxybutyrate-co-3-hydroxyvalerate)-PHBV and natural vermiculite and organoclay. The melt intercalation technique was used for obtaining systems in the form of films. The FTIR results unveiled changes in the bionanocomposites structure with the addition of the clay, verifying the incorporation and overlap of bands of both the natural clay and the quaternary ammonium salt. Through the XRD technique, it was observed a greater disorganization in the systems compared to the pure polymer, suggesting a structure of a microcomposite for the systems with natural clay and tending to a greater exfoliation for the systems with organoclay vermiculite. From the micrographs by MO and MEV, the films presented a small number of clusters for the natural systems and a more uniform structure for the organophilic systems, thus corroborating with the XRD. In this way, it was evidenced that the systems with organoclay were the ones that presented better against the characteristics desired for its possible industrial application. Thus, elaborated bionanocomposites may be an alternative to the substitution of synthetic polymers in the industry, for example, in food packaging.

The Effect of Surface Treatment with Isocyanate and Aromatic Carbodiimide of Thermally Expanded Vermiculite Used as a Functional Filler for Polylactide-Based Composites

“…Hence, it is possible to use it as an excellent insulator with high thermal stability. In addition, the possibility of exfoliation makes it a filler that can be used to create various composite and nanocomposite materials with novel functionalities [30,31].…”

Vermiculite Starch-based Nanocomposites and Applications

“…They are also effective in terms of food packaging applications and shows inertness as well in terms of interaction with food. So, these properties make them vermiculite important material [30]. Oliveira et al, (2015) studied the polyester-starch matrix-based vermiculite biodegradable nanocomposites by the melt intercalation method by using injection molding as a processing technique.…”

Avaliação do efeito do tratamento a plasma sobre a superfície de filmes de polietileno verde e argila vermiculita

“…Neste contexto, o trabalho teve como objetivo preparar via extrusão plana filmes de biocompósitos com matriz de PE Verde e carga de VMT no teor de 1%. O teor de VMT foi baseado em trabalhos publicados pelo grupo de pesquisa, sendo amplamente discutido por SILVA JÚNIOR et al [14] e REIS et al [15]. Posteriormente, os filmes receberam tratamento nas suas superfícies por meio de plasma sob duas condições distintas: sob atmosfera de oxigênio (O2) (Condição 1 -C1); e um pré-tratamento com a mistura de atmosferas de argônio/hidrogênio (Ar/H2) e o posterior tratamento por plasma sob atmosfera de O2 (Condição 2 -C2).…”