A crystalline supramolecular polymer with self-healing capability at room temperature

Abstract

The healing capability of supramolecular polymers consisting of crystalline poly(ethylene adipate) that has been end-functionalized with quadruple hydrogen-bonding ureidopyrimidinone (PEA-UPy) was studied. PEA-Toly-UPy and PEA-Hex-UPy, in which PEA and UPy are connected via tolylene and hexamethylene units, were synthesized. When these PEA-UPy polymers were torn, the degree of crystallinity at the torn surfaces decreased approximately by the amount of energy that was dissipated in the tearing process. Although the crystallinity was quickly recovered in PEA-Hex-UPy, the reduced crystallinity was maintained for a prolonged period in PEA-Toly-UPy. The dynamic nature of the hydrogen bonds gave PEA-Hex-UPy a healing capability but only at temperatures higher than Tm. Conversely, longer period of reduced crystallinity at the torn surfaces of PEA-Toly-UPy enabled self-healing at room temperature. © 2013 The Society of Polymer Science, Japan (SPSJ) All rights reserved.