Elevation of mechanically robust and reprocessable thermoset polyurea composites towards permanent shape reconfiguration controlled by heat and electricity

Abstract

Accompanying with tremendous efforts devoted to prompting recycling and mitigating disposal problems pertinent to obsolete polymer materials, it is imperative to ameliorate thermoset polymer composites that are both mechanically robust and reprocessable. Herein, we devised and prepared a series of dynamic thermoset polyurea composites (HTPU-x) by embedding CB into pristine thermoset polyurea matrix and merely using commodity raw materials. Through incorporating the dynamically sterling nature of urea bonds, the devised HTPU-x can simultaneously maintain superhigh breaking strength and elongations at break even after multiple cycles under hot press, manifesting both extraordinary mechanical properties, extraordinary reprocessability and exceptional multiple recyclability. Especially, amalgamation of the conductivity of carbon black and the dynamic nature of urea bonds can not only furnish these HTPU-x with conventional elastic shape memory performance, but also equip them with plastic shape memory and permanent shape reconfiguration under heat and electricity. Furthermore, HTPU-x can be reshaped and reconfigured to various permanent shapes in several seconds at a safe voltage. With enabling traditionally thermoset polymer composites with more upgraded functions, this designed scheme of mechanically robust HTPU-x provides a facilitating approach to reprocess and recycle the wasted thermoset polymer composites.