Preparation, Properties, and Processibility of Nanocomposites Based on Poly(ethylene-Co-Methyl Acrylate) and Multiwalled Carbon Nanotubes

Abstract

In this chapter, the preparation, characterization, processibility, and properties of nanocomposites based on multiwall carbon nanotubes (MWNTs) and different commercial grades of poly(ethylene-co-methyl acrylate) (EMA) having a variable methyl acrylate (MA) content are covered. The results showed that melt blending after solution mixing offers a simple and effective means to fabricate EMA/MWNT nanocomposites. The mechanical electrical properties and thermal degradation characteristics of the nanocomposites improve with increase in wt% of MWNT loading. The states of dispersions of the unmodified MWNTs are found to be inferior with increasing MA content in the EMA matrix. Better dispersions of MWNTs in EMA matrix lead to increased crystallite size and increased temperature of crystallization. The capillary rheological parameters can be correlated with the developed morphology under steady shear conditions. The effects of MWNTs and MA content in EMA on thermal stability and degradation kinetics are also presented. The kinetic parameters of degradation can be correlated with the degree of conversion. A promising mechanism is proposed over a different range of temperatures of degradation. The significant improvements in the mechanical and electrical properties of the polymeric matrix are observed by the addition of commercially available functionalized (hydroxyl and carboxyl) MWNTs. However, the states of dispersion of the functionalized MWNTs are found to be inferior in EMA matrix having lower MA contents. The morphology and properties of EMA-/modified MWNT-based nanocomposites are also investigated by using the plasma exposed, γ-ray irradiated, and chemically modified MWNTs. The improvement of technical properties of the matrix has been found to be higher with the plasma-modified MWNTs among all. It is also found that the electrical conductivity and EMI shielding effectiveness depend heavily on the type of functional groups present on the surface of MWNTs and also on MA content in EMA. These EMA/MWNT nanocomposites have potential applications especially, as a semiconductive layer in nuclear power plant cables, as an EMI shielding materials or as reinforced functional materials.