In　this　paper,　a　series　of　Sr-Ba-borosilicate　glass-ceramics　(10-40mole%　B　2O　3)　were　prepared　to　investigate　the　effect　of　borate　content　on　the　thermal　properties　as　well　as　volatilization　behavior.　For　crystallized　samples　with　increasing　borate　contents,　the　dilatometric　softening　points　decrease,　from　702　to　660°C,　as　do　the　coefficients　of　thermal　expansion,　from　9.5　to　7.5×10　-6K　-1.　In　addition,　the　weight　loss　from　these　materials,　in　wet　forming　gas　at　780°C　for　28　days,　decreases　by　a　factor　of　two　as　the　borate　content　increases　from　10　to　40mole%.　The　borate-containing　phase,　SrB　2O　4,　forms　with　increasing　borate　content.　The　significant　improvement　in　stability　against　volatility　can　be　attributed　to　the　formation　of　SrB　2O　4,　which　is　consistent　with　the　results　of　thermochemical　calculations.　These　results　therefore　indicate　one　way　to　design　sealing　compositions　to　use　B　2O　3　to　tailor　thermal　properties　without　sacrificing　thermal　stability.　©　2012　Elsevier　Ltd.