کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5204851 | 1381973 | 2007 | 8 صفحه PDF | دانلود رایگان |
The phosphorescence and fluorescence emitted by both the chromophores existing in raw PVC (allylic and ketoallylic structures and polyenes) and luminescent probes introduced by substitution of chlorine atoms have been used to study local features of the chain microstructure, namely the formation of blocky sequences during the nucleophilic substitution of chlorine atoms and the length and nature of the chain segments relaxing below Tg, i.e., the β relaxation. The comparison with results obtained by dynamic mechanical analysis of some of the copolymers has been carried out. Blocky sequences are found to exist and all isotactic sequences over a diad together with their heterotactic associated triads are found to participate in the β motions.
Journal: Polymer Degradation and Stability - Volume 92, Issue 12, December 2007, Pages 2300-2307