Improved Weathering Resistance of Commercial Soda-Lime Glass via Compositional Modification

Abstract

Soda-lime glass (SiO₂-CaO-Na₂O) has been widely used for various applications but suffered from weathering which is induced by the reaction between the atmospheric water and alkali or alkaline earth ions on the glass surface deteriorating the production value. In this study, composition of a commercial soda-lime glass was modified to improve its weathering resistance without significant change in its thermal properties for commercial production. Weathering resistance of the modified glasses were examined by exposing them to the condition of 85% relative humidity (RH) at 85℃ up to 20 days. Noticeable improvement of weathering resistance was observed when CaO and Na₂O contents were replace by ZnO and K₂O contents, respectively. Damaged glass surfaces due to weathering were observed with a field-emission scanning electron microscope(FE-SEM). Possible structural change of glass via compositional change was inspected by Raman spectroscopy. Thermal properties such as glass transition temperature and coefficient of thermal expansion were monitored and compared with those of the commercial reference glass.