In previous projects two methods for stabilizing crosslinked ultra high molecular weight polethylene (UHMW-PE) above the melting point have been presented. Method 1 operates at low pressure levels, while method 2 uses supercritical carbondioxide (CO2) at very high pressure levels for loading the polymer with vitamine E. In this work the suitability of both methods concerning a stabilization below the melting point at 138°C was investigated. For method 2 various impregnation temperatures, impregnation pressure levels, impregnation periods and alpha-tocopherol concentrations were used to achieve optimal stabilization conditions. Secondly, the depressurization process was optimized. A too fast decrease of pressure results in damaged samples due to expanding CO2. For method 1 various diffusion times were tested. Analyzation methods such as differential scanning calorimetry (DSC), fourier transformation infrared-spectroscopy (FTIR, transmissionelectron micoscopy (TEM), light microscopy and digital fotography were used for detection of crystallinity, alpha-tocopherol distribution and microstructural changes and damages respectively. Both methods are well suited to stabilize UHMW-PE below its melting point, with better results for method 2.
|Translated title of the contribution
|Stabilization of UHMW-PE with alpha-tocopherol below the melting point
|30 Jun 2006
|Published - 2006
Bibliographical noteembargoed until null
- ultra high molecular weight UHMW-PE crosslinked carbondioxide
- supercritical CO2 alpha-tocopherol vitamine E stabilization