Dynamics and glass transition of a starburst polymer from its low-wavenumber Raman spectrum: neat poly(propylene imine) DAB-dendr-(CN)64
✍ Scribed by Walter G. Rothschild; Michel Perrot; Raymond M. Cavagnat
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 129 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0377-0486
- DOI
- 10.1002/jrs.790
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✦ Synopsis
Abstract
We obtained experimental correlation times, in the range 11–27 ps and at temperatures between 333 and 123 K, from the low‐wavenumber VH‐Raman spectra of starburst polymer poly(propylene imine) DAB‐dendr‐(CN)~64~ in its neat state which, we propose, quantify the deformational mobility of the entire system's propylene— N < [ethylene— CN]~2~ links of its branching pattern. An activation plot of the correlation times extrapolates to a crossover value of T~c~≈225 K, which we assign as ‘spectral signature’ of the system's known, thermodynamic glass transition temperature T~G~ = 233 K. Copyright © 2001 John Wiley & Sons, Ltd.