Produção de espumas vítreas utilizando resíduo de vidro de placas fotovoltaicas.

Abstract

This thesis aimed to produce glass foams (EVs) from solid glass waste from discarded photovoltaic panels and white eggshells, together with the use of montmorillonite clay as a reinforcing agent. These foams have the potential to be used as sustainable materials for thermal and acoustic insulation in civil construction. The effect of adding montmorillonite clay in proportions of 5% and 10% on the mechanical strength of EVs was studied, while the effect of adding different proportions of foaming agent (3%, 5%, 7%, 10%, and 13%) was evaluated concerning its volumetric expansion capacity, which is directly related to its thermal and acoustic insulation capacity. Raw materials were characterized through techniques, including fluorescence and X-ray diffraction, particle size distribution by laser diffraction, and thermogravimetry. The EVs were formed by uniaxial pressing and fired at different temperatures (750, 800, 850, 900, and 950 °C) with a heating rate and a threshold set at 2.5 °C/min and 30 min, respectively. The development of the microstructure and porosity formation of the EVs were studied through scanning electron and optical microscopies where the distribution and average size of pores were observed together with the analysis of the volumetric expansion. The mechanical resistance to compression and thermal conductivity were evaluated by ASTM C 133 – 97 and ASTM E 1225 – 13 standards, respectively. The results showed that it is possible to produce EVs with high specific mechanical (EVR) strength of up to 12,17 MPa.g-1.cm3, using 10% clay and firing temperature of 900°C, maintaining a relatively low thermal conductivity (0.121 W m-1.K-1). In order to obtain EVs with lower thermal conductivity (EVE) it was possible to create EVs with thermal conductivities from 0.047 Wm-1.K-1 using raw materials with smaller granulometry. With this, this study demonstrated the viability of producing sustainable vitreous foams with applicability to the needs of high mechanical resistance or high thermal insulation.