Shape Memory Polymers (SMPs) derived from phenolic cross-linked epoxy resin via click chemistry

Phenolic cross linked-epoxy resin based shape memory thermoset was realized through ‘click’ chemistry. Towards this, propargylated novolac and bisphenol A (bis azido hydroxy propyl) ether were synthesized and characterized by FTIR and proton NMR. The functionalized resins were co-cured by click reaction between alkyne and azide group under catalyzed and uncatalysed conditions to form triazole networks. The cure reaction centered around 130 °C decreased to 74 °C on catalysis by Cu2l2. The triazole coupled phenolic-epoxy thermoset displayed shape memory properties with high foldability, shape fixity of 99% and shape recovery of 90% at a low transition temperature of 73 °C. The cross-linked matrix was thermally stable upto 250 °C under nitrogen.

Shape memory polymers were derived from phenolic crosslinked epoxy resin via click chemistry. High shape fixity and 90% shape recovery were shown by the crosslinked network at a switching temperature of 73 °C.Figure optionsDownload as PowerPoint slideHighlights
► First time reporting the shape memory properties of azide/alkyne click chemistry cured epoxy resin.
► Novolac chemistry has never been introduced for shape memory features.
► Relatively lower temperature curable epoxy resin is achieved by this approach.
► Moreover, a facile approach for incorporating features of novolac resins to epoxy polymers is described.