Arm-length-dependent phase transformation and dual dynamic healing behavior of supramolecular networks consisting of ureidopyrimidinone-end-functionalized semi-crystalline star polymers. (5th September 2020)

• Record Type: Journal Article
• Authors: Lee, Woojin; Kwak, Seung-Yeop; Chung, Jae Woo
• Is Part Of: European polymer journal. Volume 138(2020)
• Publication Date: 2020-09-05
• Subjects: Crystalline physical bond -- Dual dynamic supramolecular network -- Phase transformation -- Self-healing -- Ureidopyrimidinone; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2020.109976
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: The appropriate arm-length balance of UPy-end-functionalized star-shaped poly(ε-caprolactone)s (USPs) can provide a mechanically rigid semi-crystalline supramolecular network with highly efficient healing property. Abstract: A rigid crystalline structure suppresses chain mobility and diffusion of self-healing supramolecular networks, lowering their healing capabilities. Herein it is presented that the incorporation of crystals in self-healing supramolecular networks as an effective way to overcome the inherent lack of mechanical strength of self-healing supramolecular networks, instead of a healing barrier. We prepare dual dynamic supramolecular networks composed of two types of dynamic physical bonds, i.e., quadruple hydrogen bonds and crystalline physical bonds, using the ureidopyrimidinone (UPy)-end-functionalized semi-crystalline star-shaped poly(ε-caprolactone)s (USPs). With increasing arm-length of the USPs, the phase of the network changes from UPy-stacked crystals to an amorphous phase and further to chain-folding polymeric crystals. The healing capabilities are also enhanced with increasing the arm-length of the USPs. Such changes in phase and healing capability are strongly associated with the crosslinking density of the network. In addition, the appropriate arm-length balance of USPs can provide a mechanically rigid semi-crystalline supramolecular network with a highly efficient healing property due to their reversible dual dynamic features, associated with the re-association of UPy quadruple hydrogen bonds and restoration of crystalline physical bonds during healing.