Correlations between structure and accelerated artificial ageing of XLPE

The elucidation of the structural and morphological changes that occur during the crosslinking of polyethylene and the correlation of these changes with the physical, chemical and ageing resistance is very important to forecast the properties and the performance of the final material.The accelerated ageing of XLPE samples with various degrees of crosslinking has been carried out using two types of artificial weathering equipments, with UV or Xenon light bulbs with different cycles of temperature and humidity, varying time of exposition for both systems. The changes in the properties of the materials have been analyzed by Tensile Tests, Scanning Electron Microscopy (SEM), Dynamic-Mechanical Analysis (DMA), X-Ray Diffraction (XRD). The main degradation effects for each level of crosslinking is presented for the pristine XLPE.