Epoxy-based nanodielectrics with 2, 5 and 7 wt.% of organically modified montmorillonite clay (oMMT) were prepared using high shear melt mixing technique. The interface of oMMT and epoxy of the nanodielectrics play a very important role in improving electrical, mechanical, thermal and wear properties. Therefore detailed study on the interfacial effects of filler-matrix has been investigated for understanding the chemical bonding using Fourier transform infrared spectroscopy (FTIR) and the cross linking between polymer and filler was studied using glass transition temperature (Tg) through differential scanning calorimetry (DSC). Further, positron annihilation lifetime spectroscopy (PALS) was used to determine precise and accurate value of free volume of the nanodielectrics. The interaction between the nanoparticles and polymer chains has a direct bearing on dielectric strength characteristics of the epoxy-oMMT nanocomposite system and accordingly, the ac dielectric strength of the nanodielectrics increases with the addition of oMMT into epoxy up to 5 wt.% and further increase in filler loading (7 wt.%) causes decrease in ac dielectric strength.
Part of the book: Optimum Composite Structures
In the solar photo voltaic (PV) module, encapsulant material provides the environmental protection, insulation, optical absorption, besides serving as a good adhesive between solar cell and components of PV module for improving the efficiency. It is desired to develop an improved encapsulating material by incorporating the light absorbing inorganic nanofillers in thermoplastic polymers. One such matrix material is poly ethylene-co-vinyl acetate (PEVA), finding its importance in solar materials, such as PV modules and agricultural greenhouse polymer sheets. Inorganic nanofillers have the potential to transmit necessary radiance in the UV spectra, which can improve the PV panel efficiency. In this study, the optimum effect of inorganic fillers such as organically modified montmorillonite clay (OMMT) and titanium dioxide (TiO2) anatase in PEVA matrix is observed. The fabricated nanocomposite films were etched from the glass mold. The morphology and miscibility of fabricated nanocomposite films were analyzed and investigated by scanning electron microscopy (SEM), X-ray diffraction technique (XRD), UV-Vis absorption (UV-Vis), and Fourier-Transform Infrared Spectroscopy (FTIR). The dielectric properties of the fabricated hybrid nanocomposite films were analyzed for its insulation behavior. The thermal behavior was studied using Thermo-gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The hybrid nanocomposite with 5.0 weight percentage (wt.%) OMMT and 5.0 weight percentage (wt.%) of TiO2 indicates lowest dielectric constant of 2.4 and marginal increase in dissipation factor with respect to frequency. Increased thermal stability, glass transition temperature, high transmittance and optimum UV-shielding efficiency were found with the same wt.% in the proposed work.
Part of the book: Emerging Micro
The tribological and mechanical properties of organomodified montmorillonite (oMMT)-incorporated Epoxy (Epoxy-oMMT), vinyl ester (vinyl ester-oMMT) and titanium dioxide (TiO2)-filled Epoxy (Epoxy-TiO2) nanocomposites are discussed below. Implications of introducing oMMT and TiO2 nanoparticles on mechanical and dry sliding wear properties are presented using micrographs of cast samples and through observations of wear affected surface of nanocomposites. Distribution of nanoparticles and their influence on properties are being emphasized for understanding the wear properties. The data on mechanical and tribological properties determined experimentally are compared with published literature. The main focus is to highlight the importance of nanofillers in the design of wear-resistant thermoset polymer composites. A detailed study of strength and moduli of Epoxy-oMMT, Epoxy-TiO2 and vinyl ester-oMMT nanocomposites was taken up as a part of the investigation. A discussion on density, hardness, tensile, flexural test data, and friction and wear of nanocomposites and analysis of results by comparison with prevalent theoretical models and published results of experiments are presented.
Part of the book: Nanorods and Nanocomposites