Nanoclay effect on relaxation and thermo-mechanical properties of polymer nanocomposites

PMSE 531

Khine Yi Mya, ky-mya@imre.a-star.edu.sg, Chen Ling, Chaobin He, and Pramoda K. Pallathadka. Molecular and Performance Materials, Institute of Materials Research and Engineering, 3 Research Link, Singapore, Singapore
Polymer/clay nanocomposites have gained great interest in many years due to their high strength, thermal stability and enhanced barrier properties compared to pristine polymers. In the present study, polyimide (PI)/clay nanocomposites were prepared using a "slurry-compounding" method with a reduced amount of organic modifier (< 5 wt%). The resulting PI/clay nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), thermomechanical analysis (TMA), and dynamic mechanical analysis (DMA) to determine the morphology and thermo-mechanical properties. XRD and TEM analysis showed more exfoliated structure at PI/2.5 wt% clay and observed the degree of exfoliation in PI/5 wt% is not as good as PI/2.5 wt%. Relaxation and the interaction between clay and polymer matrix were identified by solid-state nuclear magnetic resonance spectroscopy (NMR) and X-ray photoelectron spectroscopy (XPS). Solid state 1H-NMR confirmed the better quality of clay dispersion in PI/2.5 wt% clay as compared to PI/5 wt% clay. 13C-cross polarization magic-angle (CPMAS) spectroscopy and XPS studies showed that the interaction in PI/2.5 wt% clay is much stronger than that in PI/5 wt% clay.