The dependence of the weathering of soda–lime–silica glass on environmental parameters: a preliminary investigation

The chemical resistance (durability) of glass depends both on its chemical composition and on the chemical (type and amount of the molecules interacting with the glass surface) and physical (temperature, humidity, time, etc.) environmental parameters. A wide literature is available concerning glass weathering mechanisms, mainly involving leaching processes, but only few investigate the effects of each critical parameter. This study considers the dependence of soda–lime–silica glass alteration on temperature, relative humidity and time in the case of glass in a confined environment. The aim is to simulate the experimental conditions related to the weathering of the inner surface of empty glass containers that occurs during the storage in industrial pallets. A low cost experimental apparatus was set up, in which humidity and temperature were controlled by high performance homemade devices. The dependences of humidity, temperature and time on the glass leaching and on the formation of weathering products of low durability soda–lime–silica glass was investigated by optical and electronic microscopy (SEM), x-ray microanalysis and micro-infrared reflectance spectroscopy (IRRS).