Pressureless joining of soda lime silicate glass using polysilazane-derived silica at near-room temperature

Perhydropolysilazane (PHPS) pre-ceramic polymer was used to join soda lime silicate glass at temperatures below 200 °C under pressureless conditions. The results show that: (i) the junction material is largely converted to silica at 100 °C and fully converted to glass at 150 °C; (ii) the samples treated at room temperature and 100 °C show a perfectly dense and clean bond, whereas porosity develops starting from 150 °C as a result of the hydrolysis reactions and solvent evaporation; (iii) a maximum tensile bond strength of about 5–6 MPa is obtained after treatments at 100 °C. Remarkably, after treatment at 500 °C, the junction remains intact. These preliminary findings provide the first successful attempt regarding the use of PHPS as a joining material to produce inorganic and transparent bonds for glass at relatively low temperatures.