RESUMEN
In order to reduce our dependence on nonrenewable plastics and solve the problem of non-biodegradable plastic waste, there has been much attention paid to the development of biodegradable plastics from natural resources. Starch-based materials have been widely studied and developed for commercial production, primarily from corn and tapioca. However, the use of these starches could generate food security problems. Therefore, the use of alternative starch sources, such as agricultural waste, would be of great interest. In this work, we investigated the properties of films prepared from pineapple stem starch, which has a high amylose content. Pineapple stem starch (PSS) films and glycerol-plasticized PSS films were prepared and characterized using X-ray diffraction and water contact angle measurements. All films exhibited some degree of crystallinity, making them water-resistant. The effect of glycerol content on mechanical properties and gas (oxygen, carbon dioxide and water vapor) transmission rates was also studied. The tensile modulus and tensile strength of the films decreased with increasing glycerol content, while gas transmission rates increased. Preliminary studies showed that coatings made from PSS films could slow down the ripening process of bananas and extend their shelf life.
RESUMEN
Various shapes of ZnO; multi-petals, rod and spherical were prepared and then applied on cotton fabric for UV-blocking. The ZnO particles were investigated by XRD and SEM. The mixture solution of ZnO with polyvinyl alcohol was applied onto cotton fabrics via electrospinning. The characteristics of the fabric coating were investigated by SEM, XRD, Tensile testing and Atomic absorption spectroscopy (AAS). UV-blocking property was determined by UV-vis spectrophotometer. The results of XRD and SEM on the ZnO powders show that we can produce various shape of ZnO. The investigation by SEM and AAS clearly revealed that ZnO in polyvinyl alcohol nanofibers was effectively deposited on the cotton surface. The sphericals-shaped ZnO coated fabrics show excellent UV-blocking properties. The shape of ZnO shows no considerable effect on the tensile strength of the samples.