Urethanes as reversible covalent moieties in self-healing polymers. (July 2018)

• Record Type: Journal Article
• Authors: Kuhl, N.; Abend, M.; Geitner, R.; Vitz, J.; Zechel, S.; Schmitt, M.; Popp, J.; Schubert, U.S.; Hager, M.D.
• Is Part Of: European polymer journal. Volume 104(2018)
• Page Start: 45
• Page End: 50
• Publication Date: 2018-07
• Subjects: Self-healing polymers -- Polyurethanes -- Blocked isocyanates; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2018.04.027
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Urethanes based on electron-deficient phenols are suitable as reversible covalent crosslinkers. Reversible polymer networks can be obtained by simultaneous polymerization and crosslinking. PU-based polymer networks are capable of self-healing. Raman spectroscopy can be utilized to monitor the healing process. Abstract: For the first time, reversible covalent urethane units are used for the design of new self-healing polymers. For this purpose, an electron-poor diol was synthesized and utilized as crosslinker to create a dynamic polymer network. Therefore, the diol, butyl methacrylate as well as 2-isocyanato ethyl methacrylate are intermixed and photo-polymerized in a bone-shaped PTFE mold. The resulting test specimens are characterized by DSC, TGA and DMTA and the self-healing behavior is studied using tensile tests. Thereby, healing efficiencies of up to 85% could be reached while the material exhibits good mechanical properties with high E-moduli. Additionally, the self-healing mechanism, which is based on exchange reactions of the reversible urethane moieties, is investigated by Raman as well as temperature dependent IR measurements.