Thermal, mechanical and dielectric properties of nanostructured epoxy-polyhedral oligomeric silsesquioxane composites

This paper presents the results of the thermal, mechanical and dielectric measurements conducted on polymer nanocomposites consisting of epoxy and polyhedral oligomeric silsesquioxane (POSS). The material composites were analyzed with a scanning electron microscope (SEM), an atomic force microscope (AFM) and a transmission electron microscope (TEM). Glass transition temperatures of the composites were measured with differential scanning calorimeter (DSC). Stress, strain, modulus and impact strength of epoxy nanocomposites were tested. Ac and lightning impulse (LI) breakdown strength of the composites were measured. Relative permittivity, loss factor and volume resistivity measurements were also conducted on the material samples. Two types of POSS, glycidyl and octaglycidyldimethylsilyl, were used in different quantities. Statistical analysis was applied to the measurement results to determine the effects of the additive type and amount on the properties of epoxy. The paper discusses the possibilities and restrictions in order to achieve advantages in high voltage applications using polyhedral oligomeric silsesquioxanes.