◾ Influence of Exfoliated Graphite Nanoplatelets on Properties of Polyethylene Terephthalate/Polypropylene Nanocomposites

Abstract

PET is a semicrystalline commodity thermoplastic with good mechanical properties, chemical resistance, thermal stability, low melt viscosity, and spinnability. PET has been used in several fields such as food packaging, film technology, automotive, electrical, beverages containers, and textile fibers. Despite its diversity of applications, PET is known to have poor impact properties, slow rate of crystallization, and moisture absorption, which tend to limit its use in engineering applications [2-4]. To overcome these drawbacks, PET was generally blended with other polyesters such as polybutylene terephthalate and olefinic polymers. PP is a linear olefinic commodity thermoplastic with good processability, light weight, low cost, and relatively better impact properties than PET. Its principal applications are in fiber and packaging industries. However, PP is characterized by poor flammability properties, low stiffness, low flexural modulus, and poor thermal properties that make it a poor candidate where these properties are required [5-7]. Blending PET and PP would offer an opportunity to combine the excellent properties of the two polymers due to synergistic effect and to overcome their individual shortcomings. For instance, the stiffness and heat deflection temperature of PP will be enhanced by PET, while the moisture absorption and impact strength of PET would be improved when blended with PP. Because PET and PP are thermodynamically incompatible due to differences in chemical structure and polarity, the use of suitable compatibilizers is then necessary to produce a material with desired properties. The use of elastomeric compatibilizers such as styrene-ethylene-butylenestyrene-g-maleic anhydride (SEBS-g-MAH) has led to a remarkable enhancement of the impact properties of PET/PP blends at the expense of other properties such as stiffness and strength [8].