![]() ![]() The DSC analysis shows that the crystallinity of the EPDM remains very low. Oxygenated species such as C?O? C, C=O and O?C=O groups were formed. On the other hand, an increase in oxidation with exposure time was observed for high temperatures (120 and 140 ?C). It is found that for pristine EPDM specimens and those subjected to thermal aging at 80 and 100 ?C, there was no influence of these aging temperatures on the chemical structure of the material. ![]() ![]() Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were carried out to identify the main structure changes of the material before and after thermal aging. In addition, the plausible degradation mechanism was proposed.Įthylene-propylene-diene monomer (EPDM) rubber used as power cables insulation was exposed to a thermal aging in oven for different temperatures ranging from 80 to 140 ?C. The surface degradation is a zero order reaction. The contact angles of water and formamide decreased to a minimum and then increased slowly. ![]() EPDM surface became redder, yellower and lighter in the first stage of aging and then remained almost unchanged. The results showed that hydroxyl, carbonyl and ester groups were formed during exposure to this artificial weathering environment. Furthermore, surface energy was calculated through contact angles of water and formamide. The change in surface color, contact angle and morphology was monitored by spectrophotometer, optical contact angle measuring device and Scanning Electron Microscope (SEM). The surface chemical changes were detected by Specular Reflection Fourier Transform Infrared (SR-FTIR) spectroscopy, Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS). Ethylene–propylene–diene monomer (EPDM) containing 5-ethylidene-2-norbornene (ENB) as diene was exposed to an artificial weathering environment produced by a xenon lamp light exposure and weathering equipment for different time periods. ![]()
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