Stable polystyrene glasses through PVD and UV radiation

Compared to normal glass, stable glass possesses a molecular packing much closer to that of an “ideal glass”, and thus displays extraordinarily enhanced density and exceptional kinetic stability. Stable glass prepared through physical vapour deposition (PVD) has been extensively studied in the last decade, but the technique has been applied mostly on organic small molecules such as indomethacin. Recently we have employed PVD to make stable oligomeric glasses. In this study, we use them as a starting point and extend our capacity to make high molecular weight polystyrene stable glasses. We achieve this by crosslinking the stable oligomeric glasses through dehydrogenation reaction under ultraviolet (UV) radiation. The resulting stable glasses can have significantly higher molecular weight depending on the degree of crosslinking. As characterized by ellipsometry, such network polystyrene glasses exhibit stable glass behaviours including improved density and kinetic stability.