Solubilities of nitrogen, isobutane and carbon dioxide in polyethylene

This paper describes the use of a novel method for measuring gas solubilities in polymers. It involves the use of a magnetic suspension device, an instrument with good mass sensitivity and short equilibration times that is able to operate in relatively hostile conditions, At similar temperatures and pressures, isobutane was significantly more soluble in polyethylene than carbon dioxide. The solubilities of both gases increased as the pressure was raised and decreased with increasing temperatures. The effect of temperature on gas solubility was smaller with carbon dioxide than with isobutane. Both isobutane and carbon dioxide were substantially more soluble in polyethylene than nitrogen.