Polymer Nanocomposite Materials for Structural Applications

The improvements of physicochemical and thermomechanical properties of polymer composite materials has been a major research interest in the last few decades. Polymer nanocomposites (Mohammad, 2006; Xiangling, 2003) represent a new class of materials alternative to conventional filled polymers. In this new class of material, nanosized inorganic filler (at least one dimension) are dispersed in polymer matrix offering tremendous improvement in performance properties of the polymer. Nanoscale materials have been the subject of research interest in recent years because of their unique properties as compared to the bulk counterparts and their potential applications in a wide variety of areas such as information storage, electronics, sensors, structural components, and catalysis etc. The main challenge challenge in fabrication of these polymer nanocomposites for structural applications is uniform dispersion of nanoparticles in the polymer matrix. However, good dispersion for nanoparticles in polymer composite materials is extremely difficult to achieve, since nanoparticles tend to aggregate together during fabrication. The degree with which the nanoparticles can be homogeneously dispersed in the polymer matrix would significantly influence the thermal, mechanical and optoelectronic properties of the material. Researchers have used several techniques for dispersing nanoparticles may include: 1) mechanical agitation, such as ball milling or magnetic stirring, 2) ultrasonic vibration, 3) shear mixing 4) non-contact mixing 5) using the dispersing agent. The process of curing of these polymer is an another important factor in improving the mechanical, thermal, electrical and optical properties. There is an ever-increasing demand for development of processing of polymer nanocomposites for advanced structural applications. In polymer composite fabrication, curing (polymerization) step is crucial and time-consuming process. The processing thermoplastic nanocomposites were carried out using melt extrusion, or solution casting. The epoxy based thermoset polymers are generally cured using conventional heating. The manufacturing industries of these nanocomposites are also in need of quick and efficient curing method for high temperature or room temperature curing of epoxy polymers. The conventional method of curing is timeconsuming, the longer it takes to complete a project, the more expensive it becomes. Several alternate curing methods have been tested and they are: UV rays, Gamma rays, Electron Beam and Microwave (Bogdal & Karen, 2003; Clark & Sutton, 1996), microwave heating curing of room or high temperature epoxy resins. The current chapter is focused on fabrication techniques, synthesis, and characterization of four main polymeric