کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5203551 | 1381934 | 2010 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Polypropylene degradation: Theoretical and experimental investigations Polypropylene degradation: Theoretical and experimental investigations](/preview/png/5203551.png)
The controlled-rheology peroxide degradation of polypropylene is a major issue for the industry. Combining DFT calculations - about H-abstraction onto model 2,4,6-trimethylheptane by model radicals such as t-butoxyl, methyloxyl, and methylperoxyl - with degradation studies of short chain polypropylene, we showed that the degradation depended a lot on the amount of oxygen, on the temperature, on the concentrations of both polypropylene and peroxide, and on the radicals generated from the thermal decomposition of peroxide. Besides the expected enthalpic control on the H-abstraction reaction, the bulkiness of both the oxyl radical and the reactive centre modified dramatically the regioselectivity, i.e., preferred H-abstraction from the terminal primary carbon atom by the tert-butoxyl radical vs the H-abstraction from the terminal tertiary carbon atom by methoxyl and methylperoxyl radicals.
Journal: Polymer Degradation and Stability - Volume 95, Issue 5, May 2010, Pages 782-791