Development of a standard test method for determining oxidative induction time of hydrocarbons by differential scanning calorimetry and pressure differential scanning

摘要: Test methods under the auspices of ASTM Committee E37 on Thermal Measurements are being developed for determining oxidative induction time (OIT) hydrocarbons by differential scanning calorimetry (DSC) and pressure DSC. This test method,ASTM E1858, is applicable to hydrocarbons, example, polyolefins motor oils that oxidize exothermically in their analyzed form. The DSC method used at ambient pressure, one atmosphere oxygen. (PDSC) protocol high 3.5 MPa or 500 psig, specimen reference aluminum pan heated a specific temperature, 195°C PDSC 175°C an oxygen environment. Heat flow out monitored isothermal temperature until reaction manifested heat evolution thermal curve. Statistically designed experiments aided establishing factors affecting OIT. Sample type, rate were observed as significant experimental parameters. OIT relative measure stability temperature. A precision bias statement has been reported based recent national round robin.