Silicone modified epoxy resins with good toughness, damping properties and high thermal residual weight

In this research, a series of epoxy-silicone copolymers were prepared from methyl phenyl silicone intermediates (PMPS) with a bisphenol A type epoxy resin (E-51) by condensation with dilaurate dibutyltin acting as catalyst. The chemical structure of the siloxane-bridged epoxy resin was characterized by Fourier transform infrared spectroscopy (FTIR), ¹H-NMR and an epoxy equivalent weight (EEW) test. The modified epoxy resins showed better elongation at break and izod notched impact strength than neat resin. TGA results revealed that the residue at 600 °C of the modified epoxy resin increased with the increase of siloxane content. DMA tests displayed that the addition of silicone effectively enhanced the damping properties. Morphology studies indicated that the increase in izod notched impact strength is due to the suitable diameter of silicone phases because of the silicone toughening effect.