Synthesis and Characterization of Polyurethane Nanocomposites

Abstract

Current enthusiasm in the field of the nanotechnology leads to the development of nanocomposites as one of the rapidly evolving areas of composites research. Nanocomposites are multiphase materials, where one of the phases has nanoscale dimensions. Most nanocomposites composed of just two phases, one continuous phase called matrix and other nanophase dispersed in the matrix. The objective to fabricate such nanocomposite materials is to obtain distinct properties evolved from the synergistic effects of the component materials. This may include improved physical or chemical properties, enhanced environmental stabilities that may be exploited for various applications such as military equipments, safety, protective garments, automotive, aerospace, electronics and optical devices. At present, although nanocomposites employing CNTs as carbon based fillers are dominating but graphene and graphite nanoplatelets (GNPs) are considered to open a new area of functionalized nanocomposite systems in the near future. Graphene have high enormous surface area (up to 2630 m2 g-1), high aspect ratio (200 1500), and high electrical (106 (ohm cm)-1) and thermal (400W m-1 K-1) conductivities . GNPs are small stacks of graphene and exhibits similar exceptional properties to pure monolayer graphene sheet as well as CNTs. However, though the GNPs improve the electrical properties but there is not significant change in the mechanical properties of the prepared nanocomposites. Therefore, attempts were made to use a second filler with GNPs to retain/enhance the mechanical properties of PU along with its electrical properties. Using montmorillonite (MMT) clay to reinforce polymer-based composites have raised much attention to academic and industrial sectors due to the addition of small amount of clay could substantially enhance the mechanical properties of pristine polymers.