Investigating the ageing behavior of polysiloxane nanocomposites by degradative thermal analysis

The ageing behavior of novel polysiloxane nanocomposite elastomers is reported. A series of model polysiloxane nanocomposites has been prepared incorporating the montmorillonite nanoclay Cloisite 6A. The nanoclay dispersion has been characterized with X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). TGA has been utilized to study the effects of ageing on the non-oxidative stability of the nanocomposite systems. The complex evolution of volatiles that occurs during ageing has been studied using Sub-Ambient Thermal Volatilization Analysis (SATVA). Results indicate that significant chemical changes take place within the nanocomposites upon ageing; acid catalyzed hydrolysis, chain backbiting and recombination reactions are re-structuring the polymer-filler network into a more thermodynamically stable form.