Espumas vitrocerâmicas fabricadas a partir de resíduos de vidro sódico-cálcicos

Abstract

In recent times, the topic of environmental protection has received considerable attention, and this has stimulated the development of research involving the recycling of materials. Waste glass is among the materials that attract significant interest in the concept of recycling because it is 100% recyclable and, depending on the circumstances, it can go through this process infinite times without the loss of its

properties. Therefore, this research aimed to develop glass-ceramic foams from soda- lime bottle waste, bentonite, and alumina. The polymeric replica method was used for

the processing of glass-ceramic foams, for that, 50 ppi open porosity polyurethane sponges were used as the polymer matrix. The glass-ceramic foams were prepared from 30wt%, 35wt%, and 40wt% of waste glass and with the addition of 0wt%, 2wt%, 5wt%, and 8wt% of alumina and sintered at 750 °C, 800 °C and 850 °C for 60 minutes. The effects of the contents of the waste glass, the addition of alumina, and the sintering temperatures on the physical-mechanical properties of the produced foams were investigated. X-ray diffraction analysis (XRD) was used to evaluate the amorphous/crystalline nature of the foams produced. The morphology and average pore sizes were investigated by optical microscopy images. Tests of linear shrinkage, loss of mass on fire, apparent and geometric density, porosity, water absorption, and

flexural strength were carried out to evaluate the performance of the developed glass- ceramic foams. The results of X-ray diffraction proved that the developed foams are

glass-ceramic, with calcium sodium silicate (Na2Ca3Si6O16) and cristobalite (SiO2) being the main crystalline phases identified. The foams produced with a glass content of 30wt% and 35wt% and sintered at 750 °C and 800 °C were the ones that best reproduced the structure of the polymeric sponge used as a mold. In general, the addition of alumina promoted an increase in porosity and, consequently, a reduction in the mechanical resistance to flexion. The obtained foams showed average pore sizes in the range of 240-360 μm, porosity between 52 and 85%, and flexural strength between 0.2 and 3.7 MPa.