Effects of CO2 saturation on the tensile and impact properties of polycarbonate

Polycarbonate (PC) has excellent impact and fracture properties, thus making it useful for a wide array of applications. However, it has been discovered that these properties are altered when PC is saturated with carbon dioxide (CO2) gas in a pressure vessel. PC tensile and impact were exposed to CO2 at pressures of 2.07 MPa, 4.00 MPa, and 4.48 MPa. CO2 concentration was measured as a function of time. Tensile and impact tests were conducted 1 hour, 10 days and 64 days after removal from the high pressure CO2 environment. Properties were found to vary with CO2 pressure and concentration. PC with significant CO2 concentrations has been found to undergo up to a 45% reduction in yield and ultimate strength. Impact resistance increases significantly. Even after 64 days after removal from the pressure vessel, the effects of CO2 adsorption (an increase in ductility and impact properties) were significant.