The Chemical Durability of V_2O_5-P_2O_5 System and V_2O_5-P_2O_5-BaO System Glasses

The chemical durability for water of ten kinds glasses, i. e. 40VO_<2.5>- (60-x) PO_<2.5>-xBaO system and 60VO_<2.5>- (40-x) PO_<2.5>-xBaO system glasses (x=0,5,15,25,35) was examined, because of their interesting electrical properties, i. e. their low specific electrical resistances, fomer have 10^7-10^8 ohm. cm, latter 10^5-10^6 ohm. cm. The fused glasses were powdered into particles of 35-60 meshes and 2g of them were immersed in 50 cc water of 30℃, 50℃ and 70℃ under constant agitation of 10 min., 40 min., 80 min. and 160 min. respectively. Then the amounts of V, P and Ba dissolved in water were measured by chelatometric titration.The conclusions were as following. 1) The relations btween Log of the amounts of V, P and Ba dissolved in water and the reciprocal of absolute temperature of water were linear by theory, it was found that the theory was established approximately, though some results were not accord with it. 2) The amounts of V were decreased rapidly on the addition of BaO mol, but the amounts of P were not decreased as V.