Effect of organo-Montmorillonite dispersion on properties of epoxy resin nanocomposites

Montmorillonite modified with alkyl ammonium ions was dispersed in an epoxy/methyl nadic anhydride systems to form epoxy/organo-montmorillonite (oMMT) nanocomposites. Different systems of epoxy montmorillonite nanocomposites materials were prepared by mixing at different temperature before curing. These systems were characterized by X-ray diffraction (XRD), scanning electric microscopy (SEM) and atomic force microscopy (AFM). The results of XRD illustrated that montmorillonite was exfoliated and independent upon the mixing temperature. AFM image showed a uniform dispersion of montmorillonite in the resulting nanocomposites. The results of impact and heat distortion temperature test showed that mixing temperature effected the impact and thermal properties and showed a maximum at 90degC. Compared with pristine epoxy, the impact strength and distortion temperature of the nanocomposites as prepared by mixing at 90degC before curing was simultaneously improved, 31.6% and 14degC, respectively. Morphology of fracture face of the epoxy nanocomposites was investigated by means of SEM imagines. The toughening mechanisms was also analyzed and speculated.

GENERAL INSTRUCTIONS

Polymer layered-silicate nanocomposites, known since 1961 [1], were particulate-filled composites in which the reinforcement material was in the form of sheets with thickness of one to few nanometers and length of hundreds to thousands of nanometers [2]. Due to the unique nanometer-size dispersion of the layered silicates with high aspect ratio, ratio of surface to volume and high strength in the polymer matrix, composites generally exhibit improvements in properties of polymeric materials such as mechanical performance, ablation performance, thermal stability, and barrier properties even at very low volume fraction loading (1–5%) of layered silicates [3].