PHYSICAL AND THERMAL CHARACTERISTICS OF EXPANDED FOAM GLASSES USING CRUDE GLYCEROL AS A FOAMING AGENT

Expanded foam glasses were fabricated from a clear color soda-lime silicate glass. Crude glycerol was used as an effective foaming agent which promoted small closed cell pores. This research studied the effect of crude glycerol content on the expanding characteristics and thermal properties. The expanding behavior relied on the thermal decomposition mechanism of the foaming agent as well as the sintereing temperature. Expanded foam glasses fabricated at 850°C showed uniform pore size compared to those fabricated at other temperatures (800°C and 900°C). Pore size of the synthesized foam glasses generally increased with increasing firing temperature. The evidence of black color in some areas for samples fabricated at 800°C occurred due to incomplete combustion of crude glycerol within the bulk structure. Samples produced at 850°C and 900°C showed white color shading associated with complete combustion of carbonaceous compound. Foam glasses sintered at 900°C showed structural distortion due to glass melting during the foaming process. Large holes or gaps within the structures occured due to the sweeping and combining of gas bubbles during sintering.