Assessment of polyethylene stability using the standardized OIT procedure by DSC method
Polimery 2004, No 5, 343
The standardized procedure for determination of oxidation induction time (OIT) using the differential scanning calorimetry (DSC) method has been described. A Perkin-Elmer DSC7 instrument was used and it was calibrated with indium and tin certified reference materials (CRMs). Measured values of melting temperature were consistent with the certified values within ±0.3°C. The procedure was validated using commercially available PE samples. Relative standard deviation (RSD) values were calculated and compared with the published data. The values obtained were lower than those quoted in literature for particular PE grades. Then chemically modified (grafted) PE matrices and composites with a flame retardant filler were investigated. OIT values were measured at various temperatures and the optimum measurement temperature for modified PE composites was determined. It was equal to 220°C as compared with 200°C for unmodified PE. Thus, it has been found that the thermal stability of investigated composites in thermooxidative degradation conditions is higher than that of unmodified PE material.
Keywords: thermal stability, polyethylene materials, flame retardants, oxidation induction time, relative standard deviation
Assessment of polyethylene stability using the standardized OIT procedure by DSC method (in English)