Nijagal M. Renukappa

By Rashmi Aradhya and Nijagal M. Renukappa

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

By Rashmi Aradhya and Nijagal M. Renukappa

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