Oxidation onset temperature

TABLE 1.15. Conventional DSC and pressurized-DSC (P-DSC) results showing effect of antioxidants on oxidation onset temperature (OT) of SME."... 

ASTM E2009-08 Standard Test Method for Oxidation Onset Temperature of Hydrocarbons by Differential Scanning Calorimetry. 

Focke, Walter W., Westhuizen Isbe van der. (2010). Oxidation induction time and oxidation onset temperature of polyethylene in air, J. Therm. Anal. Cal, 99,285-293. 

For oxidation onset temperature measurements (temperature ramp) at 13.6 atmospheres pressure setting, a 10°C/min heating rate was used. The sample temperature was programmed to increase at a rate of 10°C/min from 100°C to 320°C. After the test was completed, the inlet valve on the cell was closed, and the pressure was released by opening the pressure-release valve. 

Oxidative degradation is a process easily detected by DSC. Many industrial test specifications exist such as the DSC based Underwriters Laboratory test [118]. Oxidative induction time (OIT) is defined as the time to the onset of oxidation of a test specimen, exposed to an oxidising gas at an elevated isothermal test temperature. Bair [119] has described the details of the technique, using DSC, DTA, and TG. A sample is brought to the preselected isothermal (preferably in a N2 stream), the atmosphere is changed to O2 at the same flow-rate (zero time of the experiment), and the delay before the oxidation starts (detected as an abrupt departure from the baseline) then serves as an indication of the relative ox-idisability of the polymer (Fig. 2.2). It is recommended that OIT experimental conditions are selected so that OIT values are between 15 and 100 min. In dynamic DSC scans the onset temperature of the exotherm transition (Tonset) is obtained. Dynamic OIT (temperature) or OOT (oxidation onset temperature) is quicker. 

OOT Oxidation onset temperature r (1) Reaction rate (2) Intemuclear... 

Modem methods of thermal analysis can significantly reduce the time of polymer tests, and informative results, their accuracy and capability to forecast the coating lifetime are significantly improved and expanded [5-7]. In particular, the determination of oxidation induction time (OIT) and the oxidation onset temperature (OOT) by differential scanning calorimetry (DSC) is effective for the accelerated study of thermal-oxidation polymers stability. 

TABLE 10.16 Influence of Pressure on the Oxidation Onset Temperature [248]... 

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