Desenvolvimento de bioespumas empregando resíduos agroindustriais e macrofungos regionais

Abstract

The growing search for biodegradable materials has awakened the interest of the scientific world to the development of products that have this characteristic. These materials can replace synthetic products that come from petrol, such as expanded polystyrene (PS), which presents itself in a great variety of shapes and applications. Many macrofungi develop mycelium with high biological degradation rate and mechanical resistance, and, when dehydrated, beyond the low density, they become an alternative for the production of biodegradable with potential properties to replace in some applications, the PS. The present work aims to produce a biodegradable material as a potential alternative to PS (Isopor®), making use of mycelium macrofungi that come from the south of Brazil, cultured in media containing sawdust and wheat bran and/or mixtures of those substrates. The media inoculated with the macrofungi were arranged in containers so as to allow a regular shape for the bio-foam produced. After the total colonization of the macrofungi, the biofoam was dehydrated at 45°C. The biofoams are characterized by morphological, thermal, mechanical and chemical structure properties compared to PS. As a result, the existence of interaction between the matrix and the particles of the culture, established by the formation of hyphae, are identified by the electronic microscopic scanning. This morphology provides the obtention of a dense and compact structure, which justifies the results of resistance to compression obtained, superiors to the PS. In relation the thermical properties determined by thermogravimetry, the maximum temperature of degradation of the biofoams was around 40 degrees Celsius lower in relation to the PS. The results of density were superior to biofoam with 3mm thick and biofoam with 3mm thick, with average of 0.4 and 0.3 g.cm-³, respectively to the values of 0.08 and 0.03 g.cm³ of the PS samples. The results indicate that, in spite the lower thermical stability, about 14% less than the stability PS, the biofoams of macrofungi have compression resistance 60% higher in comparison to PS. It is also emphasized the biodegradable characteristics, since the material developed has a shorter degradation time and, after its use, can be used as agricultural fertilizer, potentializing its use as an alternative to PS in some applications. [resumo fornecido pelo autor]