Thermal and rheological behavior of PEG-based nanocomposites: Effect of filler aspect ratio and size

In this work, polyethylene glycol (PEG) nanocomposites containing different nanofillers (namely boehmites and hydrotalcites) were prepared through melt compounding and their thermal and rheological behavior was thoroughly investigated. The obtained results showed that the two types of nanofillers interact in a different way with the polymer matrix; more specifically, the rheological analyses performed on the systems containing hydrotalcites revealed that the presence of well-dispersed nanofillers strongly affects the relaxation dynamics of the PEG macromolecular chains, resulting in a modification of the rheological functions of unfilled matrix. Furthermore, the nanocomposites containing higher loadings of organo-modified hydrotalcite exhibit an unusual rheological behavior as a function of temperature, showing an enhancement of the linear viscoelastic functions along with a more important solid-like feature with increasing the temperature. Finally, the thermo-oxidative stability of the obtained nanocomposites was enhanced in the presence of boehmites and unmodified hydrotalcite, while the high organic fraction content in modified hydrotalcite promoted an anticipated degradation of the polymer matrix.