Adhesive properties of poly (methyl silsesquioxanes)/bio-based epoxy nanocomposites

Abstract

Poly(methyl silsesquioxanes), PMSQ, are cyclic siloxanes with unusual features that are also widely known as silsesquioxanes due to their organic peripheral and inorganic silicate interior. These are organosilicon compounds with the chemical formula [RSiO3/2]n that are called silsesquioxanes where R may be alkyl, alkoxyl or aryl. These hybrid materials are quite famous to exhibit garner properties from their different inorganic and organic parts in a synergistic way. However, dealing with long-standing challenges and environmentally friendly requirements, we synthesized these PMSQ fine nanoparticles in our own laboratory. These nanoparticles were uniformly dispersed in a bio-based epoxy resin, and the mechanical properties, adhesive strength, and morphology of resultant nanocomposites were evaluated. PMSQ were found to be successfully dispersed into the bio-based epoxy resin in varying weight fractions of 1 wt%, 3 wt% and 5 wt%. The mechanical properties of PMSO-loaded epoxy resin samples are reported as functions of processing parameters. The highly dispersed PMSQ/bio-based epoxy resin nanocomposites showed high tensile modulus and strength values. In addition, it was found that fracture toughness values of all samples prepared by ultra-sonication were increased by increasing PMSQ content in nanocomposites. The corresponding synthesized epoxy resin composites were characterized by different techniques including, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). SEM analysis reported high uniformly dispersed spherical PMSQ particles in epoxy resin. The bonding properties including, tensile modulus and strength of PMSQ were determined using a general testing machine. The obtained results confirmed a significant improvement in bonding performance of PMSQ dispersed in bio-based epoxy resin. PMSQ attracts feasible widespread applications in mechanical and environmental engineering.