English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/48252
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Effect of blending on the chain dynamics of the “Low-Tg” component in nonentangled and dynamically dsymmetric polymer blends

AuthorsArrese-Igor, Silvia ; Alegría, Ángel ; Moreno Segurado, Ángel J. ; Colmenero de León, Juan
Issue Date2011
PublisherAmerican Chemical Society
CitationMacromolecules 44(9): 3611-3621 (2011)
AbstractWe have studied polyisoprene (PI) component chain dynamics in poly(tert-butylstyrene) (PtBS) miscible blends of low molecular weight over the entire composition range by broadband dielectric spectroscopy (DS). Blends with two different molecular weight of PtBS, Mn = 1300 Da and Mn = 2300 Da, having notably different glass transition temperatures, Tg = 330 K and Tg = 373 K, respectively, have been investigated. The molecular weight for PI was Mn = 2700 Da, and Tg = 204 K, i.e., well below the Tg of PtBS. The molecular weights of all the polymers were chosen in order to be well below the entanglement limit for PI. In addition to the slowing down of the dielectric response of PI as the high-Tg component PtBS increases, there is a gradual broadening of both low- and high-frequency tails of the normal mode relaxation as PtBS% increases and for a given composition as the temperature decreases. The magnitude of the broadening depends on (i) the concentration, (ii) the temperature, and (iii) the dynamic asymmetry, i.e., the difference between the pure component’s Tg. The onset of the mentioned broadening correlates well with the freezing of the segmental relaxation of the high-Tg PtBS component. Finally, the terminal dynamics of PI component shows a stronger T-dependence than its segmental dynamics, and the effect is more pronounced the higher the PtBS content. As a result, the separation between the maxima of both relaxations ranges from 3 decades in pure PI and PI ≥ 50% content blends to 5 decades for 20% PI blends. The results are discussed in terms of the dynamic asymmetry between the different blend components and compared with simulation results of dynamically asymmetric bead−spring polymer blends showing anomalous scaling behavior of the Rouse modes.
Description11 páginas, 15 figuras.
Publisher version (URL)http://dx.doi.org/10.1021/ma2000064
Appears in Collections:(CFM) Artículos
Files in This Item:
File Description SizeFormat 
accesoRestringido.pdf15,38 kBAdobe PDFThumbnail
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.