Understanding the effect of the fishbone-shaped networks on damping, thermal, and hydrophobicity properties

Abstract

Based on an allyl-based epoxy resin (DADGEBA), a series of fishbone-shaped polymers were deliberately designed by reacting with hydride terminated methyl phenyl polysiloxane. The GPC, FTIR, and 1H NMR spectra confirmed that their structures can be tuned by the molar ratio between polysiloxane and epoxy. Results indicated that the proportion of fishbone networks has a profound effect on curing behavior, thermal, damping, surface and mechanical properties. Especially, when the fishbone networks become dominant in the networks, the introduction of flexible polysiloxane part will not decrease the intense internal friction due to the anchor sites. That is, the values of tan δ (max) exhibit as a characterization constant. Furthermore, the cured XEP-80 presents the widest transition range spanning over 150 °C with a peak half-width of 69 °C. These results are promising in the epoxy/polysiloxane industry to guide the synthesis of low-temperature damping adhesive for engineering application.