Viscoelastic and mechanical properties of polyimide-clay nanocomposites

Polyimide-clay nanocomposites were prepared by blending 2.5 and 5 wt.% of PGV (Na+-montmorillonite) and two organically modified PGV (PGVC10COOH, PGVC12) with a methanol solution of PMR-15 precursor. DMA results showed a significant increase in the thermomechanical properties (E' and E") of 2.5 wt.% clay loaded nanocomposites in comparison with the neat polyimide. Increasing the clay loading to 5 wt.% degraded these properties. Higher T(g)s were observed for 2.5 wt.% nanocomposites compared to the neat polyimide. A lower CTE was observed only for the PGV/PMR-15 nanocomposite. Flexural properties measurements for the 2.5 wt.% nanocomposites showed an improvement in the modulus, strength and elongation. This trend in the tensile properties was not observed for the 5 wt.% nanocomposites.