Influence Factor Analysis and Measurement Uncertainty Evaluation on Oxidation Induction Time of Plastics

Taking a black polyethylene particles as the research object, according to GB/T 19466.6-2009, the oxidation induction time (OIT) of the sample at a constant temperature of 220℃ was measured, and the influence of the sample mass, constant temperature, oxygen flow rate and other parameters on the measurement result was discussed. And then the standard uncertainty components introduced during the measurement were evaluated according to JJF 1059.1-2012. The results show that the most important factors affecting the OIT measurement results were measurement repeatability and constant temperature, and oxygen flow and sample mass had little effect on the measurement results. The expanded uncertainty of OIT of the polyethylene measured by differential scanning calorimetry method was as following:U=1.5 min when the coverage factor k=2.