Real-time monitoring of molecular dynamics of ethylene glycol dimethacrylate glass former

Viciosa, M. T., Correia, N. T., Salmerón-Sanchez, M. , Carvalho, A. L., Romão, M. J., Gómez Ribelles, J. L. and Dionísio, M. (2009) Real-time monitoring of molecular dynamics of ethylene glycol dimethacrylate glass former. Journal of Physical Chemistry B, 113(43), pp. 14209-14217. (doi: 10.1021/jp903212g)

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Abstract

The isothermal cold-crystallization of the glass-former low-molecular-weight compound, ethylene glycol dimethacrylate (EGDMA), was monitored by real-time dielectric relaxation spectroscopy (DRS) and differential scanning calorimetry (DSC). The α-relaxation associated with the dynamic glass transition as detected by DRS was followed at different crystallization temperatures, T<sub>cr</sub>, nearly above the glass transition temperature, 176 K (1.06 ≤ T<sub>cr</sub>/<sub>Tg</sub> ≤ 1.12). It was found that the α-process depletes upon cold-crystallization with no significant changes in either shape or location. At advanced crystallization states, a new relaxation, α′-process, evolves that was assigned to the mobility of molecules lying adjacent to crystalline surfaces. From the time evolution of the normalized permittivity, it was possible to get kinetic information that was complemented with the calorimetric data. From DSC measurements that were also carried out under melt-crystallization, an enlarged temperature range was covered (up to T<sub>cr</sub>/T<sub>g</sub> = 1.24), allowing us to draw a diagram of time−temperature crystallization for this system. Dielectric relaxation spectroscopy proved to be a sensitive tool to probe the mobility in the remaining amorphous regions even at high crystallinities.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Salmeron-Sanchez, Professor Manuel
Authors: Viciosa, M. T., Correia, N. T., Salmerón-Sanchez, M., Carvalho, A. L., Romão, M. J., Gómez Ribelles, J. L., and Dionísio, M.
College/School:College of Science and Engineering > School of Engineering > Biomedical Engineering
Journal Name:Journal of Physical Chemistry B
ISSN:1520-6106
ISSN (Online):1990-7923
Published Online:05 October 2009

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