Solid-state mechanical properties of PE/PA blends filled with organoclay or compatibilized by a graft co-polymer: A comparative study

The comparative study of solid-state linear and non-linear tensile properties of polyethylene/polyamide (80/20) blend with nodular morphology, compatibilized by a graft-copolymer or filled by nanoclay, was reported. Clay and compatibilizer volume fractions were varied from 0.5 to 2.5% relative to PA. Scanning electron microscopy and transmission electron microscopy were performed to investigate the dispersed phase morphology and the structure of the PA-intercalated clay interphase. For the same fraction of clay or compatibilizer, PA nodules were shown to exhibit the same average diameter, allowing the comparison between the two systems. When adding very small amounts of clay or compatibilizer, the Young's modulus was shown to strongly decrease; however, once the interface was saturated, further addition increased the Young's modulus of filled blends, much more markedly than that of compatibilized blends. The elongation at yield and yield strength were improved by addition of the compatibilizer, whereas addition of nanoclay was shown to have the opposite effect. At last, tensile strength and elongation at break were significantly improved compared to those of the neat blend, for both systems. The differences in mechanical properties between the two systems have been discussed in terms of differences in interphase structure.