Adaptable Hetero Diels–Alder Networks for Fast Self‐Healing under Mild Conditions

Abstract

A novel adaptable network based on the reversible hetero Diels-Alder reaction of a cyanodithioester and cyclopentadiene is presented. Reversible between 50-120 °C, the adjustable and self-healing features of the network are evidenced via temperature dependent rheology experiments and repetitive tensile tests whereas the network's chemical structure is explored by temperature dependent (1) H MAS-NMR spectroscopy.

Design of a thermally controlled sequence of triazolinedione-based click and transclick reactions

“…9–15 This reversibility feature at first seems contradictory to some of the original Sharpless criteria such as the need for stable reaction products and the ‘spring loaded’ thermodynamic driving force. Nevertheless, there are many attractive applications in materials science that require a certain extent of reversible behavior for covalent bond forming reactions.…”

A Transparent, Self‐Healing, Highly Stretchable Ionic Conductor

“…Ionomers, a commercially available self-healing polymer, [45] require an external stimulus such as temperature to increase polymer chain mobility and activate self-healing. [4][5][6][7][8][9][10][11][12][13][14][15][16] The ability to rationally tune and add new functionality in materials can lead to transformative advances in emerging self-healing systems. This material tolerates extreme strains exceeding 5000%, features an ionic conductivity of 10 −4 S cm −1 , and shows high transparency across the visible spectrum with an average transmittance of 92%.…”

Responsive Polymers as Sensors, Muscles, and Self-Healing Materials

“…To address this limitation, a reversible system based on hetero Diels-Alder (HDA) reactions, utilizing acid activated dithioesters as dienophiles and cyclopentadiene (Cp), has been developed ( Fig. 13) [60]. A novel self-healing material was prepared using a cyanodithioester (CDTE) compound/Cp HDA pair.…”

“…Once S-S bonds are incorporated into low glass transition temperature (T g ) gel networks, room-temperature bond interchange is possible. Poly(n-butyl acrylate) grafted star polymers were prepared by chain extension atom transfer [60] radical polymerization (ATRP) from cross-linked cores. The cross-linked core is comprised of poly(ethylene glycol diacrylate), which was further utilized as macroinitiator for the consecutive chain extension of bis(2-methacryloyloxyethyl disulfide) [66].…”