Universal Features of the Melt Elasticity of Interacting Polymer Nanocomposites

详细信息    查看全文

• 作者：G. Capuano ; G. Filippone ; G. Romeo ; D. Acierno
• 刊名：Langmuir
• 出版年：2012
• 出版时间：March 27, 2012
• 年：2012
• 卷：28
• 期：12
• 页码：5458-5463
• 全文大小：358K
• 年卷期：v.28,no.12(March 27, 2012)
• ISSN：1520-5827

文摘

We study the structure and linear viscoelasticity of interacting polymer nanocomposites based on mixtures of poly(ethylene oxide) and fumed silica particles. The filler is dispersed within the polymer using two different techniques which lead to different dispersion states. The analysis of the dynamic response of our systems highlights the formation of a stress-bearing network above a critical volume fraction, 桅_c. Extending a two-phase model used to describe weakly interacting systems, we show that above 桅_c the melt-state elasticity of the composites arises from the independent contributions of a polymer鈥損article network and a viscous matrix. We also find that, although 桅_c depends on the initial state of dispersion, the network elasticity scales with volume fraction following a universal power-law, with an exponent 谓 鈮?1.8. Such a scaling law has been recently predicted for the stress-bearing mechanism governed by polymer-mediated interactions.