Dynamics of in situ synthetized silver-epoxy nanocomposites as studied by dielectric relaxation spectroscopy

• Published in: Journal of applied polymer science Vol. 120; no. 4; pp. 2361 - 2367
• Main Authors: Kortaberria, G, Arruti, P, Mondragon, I, Vescovo, L, Sangermano, M
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.05.2011; Wiley; Wiley Subscription Services, Inc
• Subjects: Applied sciences; Composites; dielectric; Dynamic tests; Dynamics; epoxy; Exact sciences and technology; Forms of application and semi-finished materials; Heterogeneity; Materials science; Mathematical analysis; molecular dynamics; Nanocomposites; Nanoparticles; Polymer industry, paints, wood; Polymers; Relaxation time; Spectroscopy; Technology of polymers; Diepoxide; Ring opening polymerization; Dielectric properties; epoxy; Experimental study; Metal particle; molecular dynamics; nanocomposites; Composite material; Dielectric relaxation; Thermal properties; Silver; Cyclic ether polymer; nanoparticles; Local mobility; Photopolymerization; Preparation; Concentration effect; Nanocomposite; Activation energy; dielectric
• ISSN: 0021-8995; 1097-4628; 1097-4628
• DOI: 10.1002/app.33440

In situ synthetized silver-photocurable epoxy resin nanocomposites were analyzed by dielectric spectroscopy to study the local dynamics at temperatures well below the glass-transition temperature and the effect of silver nanoparticles on them. Two secondary processes, β and γ, were detected both for the neat matrix and nanocomposites. Relaxation times of the β secondary relaxation, obtained by fitting to Havriliak-Negami equation, were lower in the nanocomposites, as well as the activation energies calculated from the Arrhenius temperature dependence of relaxation times, due to the plasticization effect of the trapped solvent. The electric modulus formalism was used to detect the interfacial or MWS polarization, present both in the neat matrix and in the nanocomposites due to heterogeneities and interfaces. The activation energy of this relaxation increased with nanoparticle content, thus indicating an increase of the heterogeneities due to the nanoparticles.