Accelerated α Relaxation Dynamics in the Exfoliated Nylon-11/Clay Nanocomposite Observed in the Melt and Semicrystalline State by Dielectric Spectroscopy

Published

January 1, 2005

Author(s)

Bur A. LeeYH, Start P. RothSC

Abstract

A new dielectric slit die sensor attached to the end of an extruder was designed to elucidate the melt properties of nylon 11 nanocomposites filled with organically treated clays. Light transmission data were also obtained from an online optical sensor that monitored the composites upon extrusion. The combination of online optical and dielectric measurements enables us not only to quantitatively determine the exfoliation scale but also to establish a correlation between the microstructure the clay filler and the relaxation behavior of polymer matrix. Only one relaxation, a, was detected in the neat resin and yet two relaxations, a and Maxwell-Wagner-Sillars interfacial polarization (MWS), were retrieved from all the composites including the aggregated system filled with untreated sodium clay.MWS relaxation, ascribed to the polarization at the polymer/filler interface, shows a much broader relaxation time distribution than the dipolar a relaxation as each interface, bearing various interfacial geometries, is polarized at a distinct time scale. The a dynamics remained nearly unchanged regardless of the filler dispersion but the MWS polarization was altered drastically. A much longer MWS relaxation time was found in the highly exfoliated system where evenly distributed silicate fillers serve as excellent nano-capacitors. A much greater MWS dielectric magnitude was yielded in the state of exfoliation compared to the aggregation as ionic surfactants were released to the molten resin upon the delamination of the stacked silicate layers.

Citation

Macromolecules

Volume

38

Issue

No. 9

Pub Type

Journals

Keywords

alpha relaxation, dielectric, exfoliated, Maxwell-Wagner-Sillars interfacial, microstructure, polarization, polyamide

Citation

LeeYH, B. and RothSC, S. (2005), Accelerated α Relaxation Dynamics in the Exfoliated Nylon-11/Clay Nanocomposite Observed in the Melt and Semicrystalline State by Dielectric Spectroscopy, Macromolecules (Accessed May 17, 2024)