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 env… Show more
“…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].…”
In this work, thermally expanded vermiculite (TE-VMT) was surface modified and used as a filler for composites with a polylactide (PLA) matrix. Modification of vermiculite was realized by simultaneous ball milling with the presence of two PLA chain extenders, aromatic carbodiimide (KI), and 4,4’-methylenebis(phenyl isocyanate) (MDI). In addition to analyzing the particle size of the filler subjected to processing, the efficiency of mechanochemical modification was evaluated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The composites of PLA with three vermiculite types were prepared by melt mixing and subjected to mechanical, thermomechanical, thermal, and structural evaluation. The structure of composites containing a constant amount of the filler (20 wt%) was assessed using FTIR spectroscopy and SEM analysis supplemented by evaluating the final injection-molded samples’ physicochemical properties. Mechanical behavior of the composites was assessed by static tensile test and impact strength hardness measurements. Heat deflection temperature (HDT) test and dynamic thermomechanical analysis (DMTA) were applied to evaluate the influence of the filler addition and its functionalization on thermomechanical properties of PLA-based composites. Thermal properties were assessed by differential scanning calorimetry (DSC), pyrolysis combustion flow calorimetry (PCFC), and thermogravimetric analysis (TGA). The use of filler-reactive chain extenders (CE) made it possible to change the vermiculite structure and obtain an improvement in interfacial adhesion and more favorable filler dispersions in the matrix. This translated into an improvement in impact strength and an increase in thermo-mechanical stability and heat release capacity of composites containing modified vermiculites.
“…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].…”
In this work, thermally expanded vermiculite (TE-VMT) was surface modified and used as a filler for composites with a polylactide (PLA) matrix. Modification of vermiculite was realized by simultaneous ball milling with the presence of two PLA chain extenders, aromatic carbodiimide (KI), and 4,4’-methylenebis(phenyl isocyanate) (MDI). In addition to analyzing the particle size of the filler subjected to processing, the efficiency of mechanochemical modification was evaluated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The composites of PLA with three vermiculite types were prepared by melt mixing and subjected to mechanical, thermomechanical, thermal, and structural evaluation. The structure of composites containing a constant amount of the filler (20 wt%) was assessed using FTIR spectroscopy and SEM analysis supplemented by evaluating the final injection-molded samples’ physicochemical properties. Mechanical behavior of the composites was assessed by static tensile test and impact strength hardness measurements. Heat deflection temperature (HDT) test and dynamic thermomechanical analysis (DMTA) were applied to evaluate the influence of the filler addition and its functionalization on thermomechanical properties of PLA-based composites. Thermal properties were assessed by differential scanning calorimetry (DSC), pyrolysis combustion flow calorimetry (PCFC), and thermogravimetric analysis (TGA). The use of filler-reactive chain extenders (CE) made it possible to change the vermiculite structure and obtain an improvement in interfacial adhesion and more favorable filler dispersions in the matrix. This translated into an improvement in impact strength and an increase in thermo-mechanical stability and heat release capacity of composites containing modified vermiculites.
“…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.…”
Section: Vermiculite-modified Bio Nanocompositesmentioning
Nowadays, the demand of biodegradable as well as biocompatible nanocomposites-based products is growing all over the world. In this perspective, a little effort is done in terms of exploring the effectiveness of environment friendly vermiculite starch-based nanocomposites. Both the constituents are naturally occurring so they are considered as low-cost materials. Different methods such as solution casting, melt solution blending as well as in-situ polymerization approaches are used for the fabrication of vermiculite starch-based nanocomposites. Functional characterization of nanocomposites can be investigated in terms of XRD, SEM, FTIR, TGA, DSC as well as by some mechanical testing methods. The resultant nanocomposites give attractive solutions in the subject of wastewater treatment and food packaging additionally may also exhibits improved fire properties that are resistive.
“…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).…”
RESUMO O Polietileno (PE) Verde é um polímero sintético que apresenta baixa energia superficial, que resulta em fraca propriedade de adesão. Esta baixa adesão, provoca alguns problemas relativos às aplicações práticas dos polímeros, como fraca aderência de tintas de impressão, revestimentos, adesivos e metais à superfície do polímero, entre outros. Uma maneira de alterar essa propriedade é por meio da aplicação de um tratamento por plasma. Neste sentido, o objetivo deste trabalho foi preparar, via extrusão plana, filmes de biocompósitos com matriz de PE Verde (PEPURO) e carga de argila Vermiculita Expandida (VMT) no teor de 1%. Os filmes foram tratados por plasma em duas condições distintas: sob atmosfera de Oxigênio (O2) (C1); e sob atmosfera correspondendo a mistura de Argônio/Hidrogênio (Ar/H2) e um posterior tratamento por plasma sob atmosfera de O2 (C2). Os resultados indicaram que os tratamentos a plasma e a incorporação de VMT aumentaram a hidrofilicidade dos filmes, sendo que a aplicação da condição 2 (C2) mostrou-se de maneira mais eficiente. O PEPURO não tratado apresentou redução significativa de resistência máxima a tração com a inserção de VMT, já com a aplicação dos tratamentos (C1 e C2) os valores de resistência foram superiores. Em relação à rugosidade foi possível verificar que a aplicação do plasma aumentou a rugosidade na superfície das amostras. Estes resultados indicaram que o aumento da hidrofilicidade e da rugosidade resultaram em um aumento significativo na interação de fluidos com a superfície e também melhora das características adesivas do polímero.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.