RESUMEN
This study presents the development and characterization of a nanocomposite material, consisting of thermoplastic starch (TPS) reinforced with bentonite clay (BC) and encapsulated with vitamin B2 (VB). The research is motivated by the potential of TPS as a renewable and biodegradable substitute for petroleum-based materials in the biopolymer industry. The effects of VB on the physicochemical properties of TPS/BC films, including mechanical and thermal properties, water uptake, and weight loss in water, were investigated. In addition, the surface morphology and chemical composition of the TPS samples were analyzed using high-resolution SEM microscopy and EDS, providing insight into the structure-property relationship of the nanocomposites. The results showed that the addition of VB significantly increased the tensile strength and Young's modulus of TPS/BC films, with the highest values observed for nanocomposites containing 5 php of VB and 3 php of BC. Furthermore, the release of VB was controlled by the BC content, with higher BC content leading to lower VB release. These findings demonstrate the potential of TPS/BC/VB nanocomposites as environmentally friendly materials with improved mechanical properties and controlled release of VB, which can have significant applications in the biopolymer industry.
Asunto(s)
Nanocompuestos , Almidón , Almidón/química , Bentonita/química , Arcilla , Riboflavina , Resistencia a la Tracción , Nanocompuestos/química , Agua , VitaminasRESUMEN
This study reports the preparation of a novel type of support based on magnetically recyclable bentonite functionalized with divinylbenzene-polyvinyl pyridine (PVP-DVB) for Pd (II) nanocatalyst by a simple cost-effective method. Firstly, the conventional co-precipitation method synthesized Fe3O4 nanoparticles (NPs) onto bentonite sheets. Then the prepared magnetic support surface was functionalized by divinylbenzene-polyvinyl pyridine (PVP-DVB) to create a cross-linked polymer with a high coordination ability with palladium. Repeated nitrogen units in the PVP-DVB polymer chain increase the number of Pd bonds and thus lead to higher performance of the nanocatalyst. Finally, the palladium NPs were simultaneously synthesized and immobilized under mild conditions. The synthesized nanocatalyst was characterized by several methods such as scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, vibrating sample magnetometer, inductively coupled plasma mass spectrometry and thermogravimetric analysis. The efficiency of synthesized heterogeneous nanocatalyst was investigated in Suzuki-Miyaura cross-coupling reactions between a range of aryl halides (X = Cl, Br, I) with phenylboronic acid and in the reduction of 4-nitrophenol (4-NP). Moreover, the synthesized nanocatalyst could be easily recovered and reused several times with an efficiency greater than 90%.