Vitrimeric Shape-Memory Polymers with Intrinsic Flame Retardancy and Self-Healing Capabilities.

Abstract

This work introduces a vitrimeric shape-memory polymer (SMP) with inherent flame retardancy and self-healing capability. The multifunctional system is achieved by crafting a dynamic network through the strategic imination and methacrylation of a polyether diamine (PED). This strengthens PED with, both, dynamic imine bonds for reshaping and functional methacrylate groups for network formation. Further reaction with phosphorus-based acrylate allows precise tailoring of the network's mechanical and thermal properties along with flame retardancy. The key lies in the dynamic imine bonds, enabling SMP to exhibit remarkable vitrimeric behavior and self-healing functionality. The networks are deformed at high temperature (≈150 °C) for permanent shape change, providing exceptional reprogrammability. The inherent flame retardancy stems from the high phosphorus content, achieving an impressive limiting oxygen index (LOI) of 29% and a V-1 rating in the UL 94 vertical burning test. This groundbreaking research paves the way for a new generation of sustainable materials with exceptional multi-functionalities like flame retardancy, self-healing, and shape-memory.