Authors: W. Chian, C. Mallampalli and R.M. Winter
Affilation: South Dakota School of Mines & Technology, United States
Pages: 107 - 110
Keywords: adhesion behavior, POSS, reinforcement of epoxy adhesives
ABSTRACT The reinforcement of epoxy adhesive with polyhedral-Oligomeric-SilSesquioxane (POSS) was studied. Shear performance of the nano-filled adhesive was evaluated as a function of filler content using the single-strap bonded joint configuration. It is found that maximal stress and shear strain both monotonically increased with the POSS loading. X-ray diffraction (XRD) analyses indicated that the inorganic POSS crystal and nano-cages on POSS remained intact over the cure cycle. The percentage of POSS filler had no significant impact on the apparent glassy shear modulus, as was indicated by mechanical tests of made bonded joints at room temperature as well as modulus profiling of the bondline using interfacial force microscopy (IFM). Dynamic mechanical analysis (DMA) of filled adhesives showed that network elasticity increased with the addition of POSS. The enhanced chain mobility and reduced internal stress within the bondline contributed favorably to the polymer/metal interaction at the interface, resulting in the increased adhesion strength and interfacial toughness, as was indicated by the observed shift in the failure mode from adhesive to cohesive for the bonded joints with increased POSS content.