Title of article :
Living radical polymerization of styrene mediated by a piperidinyl-N-oxyl radical having very bulky substituents
Author/Authors :
Mannan، نويسنده , , Md. Abdul and Ichikawa، نويسنده , , Ayako and Miura، نويسنده , , Yozo، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2007
Pages :
7
From page :
743
To page :
749
Abstract :
A new cyclic nitroxide 1 and the corresponding alkoxyamines 9 and 10 were synthesized and the polymerization of styrene (St) initiated with 10 was investigated. The NO–C bond of 9 is very weak, cleaving at room temperature. On the other hand, alkoxyamine 10 is stable at room temperature and the Aact and Eact for the NO–C bond homolysis were determined to be 1.4 × 1015 s−1 and 124.5 kJ mol−1, respectively. When the polymerization of St was carried out at 70 °C, the resultant poly(St) showed narrow polydispersities below 1.25. In the polymerization at 90 °C, the resulting poly(St) showed narrow polydispersity until 60% conversion, but Mw/Mn was rapidly increased above 60% conversion. On the other hand, the polymerization at 120 °C gave poly(St) with broad polydispersities. The unusual polymerization behavior was discussed on the basis of the SEC and ESR results.
Keywords :
Nitroxide , styrene , Living radical polymerization
Journal title :
Polymer
Serial Year :
2007
Journal title :
Polymer
Record number :
1728288
Link To Document :
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