PRELIMINARY STUDY FOR THE DEVELOPMENT OF FOAMS BASED ON CASSAVA STARCH, CLAY AND RAMI FIBERS FOR USE IN PACKAGING
Starch foam. Packing. ramie fiber. Nanoclay.
The inadequate destination and final disposal of plastics have been causing very serious environmental problems. This is because microplastics are already consumed by humans, being present in seafood, water and soil. Expanded polystyrene (EPS) contributes to the current scenario, as it is used in single-use packaging. Therefore, this study aimed to develop starch foams, ramie fibers and organically modified montmorillonite clay. For this, the constituents were stirred with the aid of a mixer and the foams were molded under pressure and temperature. Different concentrations of starch (75 to 100 g / 100 g of solids), ramie fibers (0, 10, 15 and 20 g / 100 g of solids), clay (0 and 5 g / 100 g of solids) and water were used. (100 to 275 mL/100 g solids). At first, the foams were characterized in terms of density, morphology, mechanical and thermal properties, to assess the influence of fibers and nanoclay on these properties. In a second moment, foams were produced based on three different starches: waxy corn, cassava and potato and characterized in terms of their ability to absorb water and moisture. The micrographs obtained indicated good expansion of the material and good dispersion of fibers and nanoclay. Infrared spectra indicated greater water absorption by samples containing ramie fibers. The thermal analysis indicated a slight increase in the thermal stability of the foams with the addition of these materials. Mechanical tests indicated an increase in strength with the addition of ramie fibers. In the second stage of analysis, it was verified that nano-agile reduced the water absorption capacity of the foams and that the waxy corn starch presented lower rates of water absorption and humidity. Thus, it was concluded that foams produced can be used as packaging, but are limited to store products with low water contents.