Thermal Oxidation and Structural Changes of Degraded Polyethylene in an Oxygen Atmosphere |
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| Authors: | Hui-Juan Huang Quan-Bing Wang Bang-Hu Xie Wei Yang Ming-Bo Yang |
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| Institution: | College of Polymer Science and Engineering , State Key Laboratory of Polymer Materials Engineering, Sichuan University , Chengdu , 610065 , P. R. China |
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| Abstract: | High-temperature bulk thermolysis of high density polyethylene was performed to obtain degraded polyethylene, which was then left in an oxygen atmosphere for oxidation reaction at 160°C at different oxidation times, yielding a series of polyethylene degradation–oxidation products. Using infrared spectroscopy, chemical titration, gel chromatography, and differential scanning calorimetry, the structural changes of the polyethylene degradation–oxidation products were investigated. Hydroxyl, carboxyl, ester, and other functional groups were introduced into the molecular chains of oxidation products, and the number of carboxyl groups sharply increased with increasing oxidation time. The breaking of molecular chains as well as combination reactions, such as esterfication, during the oxidation process lead to decrease of number-average molecular weight (  | |
| Keywords: | acid value carboxyl number per molecular chain esterfication polyethylene degradation–oxidation products terminal vinyl |
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