A Guiding Principle for Strengthening Crosslinked Polymers: Synthesis and Application of Mobility‐Controlling Rotaxane Crosslinkers

• Published in: Angewandte Chemie International Edition Vol. 58; no. 9; pp. 2765 - 2768
• Main Authors: Sawada, Jun, Aoki, Daisuke, Otsuka, Hideyuki, Takata, Toshikazu
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 25.02.2019; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Chemical synthesis; Chemistry; Chemistry, Multidisciplinary; Crosslinking; Mechanical properties; Mobility; Physical Sciences; Polymerization; Polymers; Ring opening polymerization; rotaxanes; Science & Technology; supramolecular chemistry; synthetic methods; Tensile stress; LINKING; NETWORK; rotaxanes; SIZE-COMPLEMENTARY; BLOCK; POLYROTAXANE; RADICAL POLYMERIZATION; polymers; supramolecular chemistry; mechanical properties; synthetic methods
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201813439

Three component mobility controlling vinylic rotaxane crosslinkers with two radically polymerizable vinyl groups (RC_Rs) were synthesized to prove that the mobility of the components of the RC_Rs plays a crucial role in determining the properties of rotaxane‐crosslinked polymers (RCPs). RC_Rs (R=H, Me, or Et) were obtained from living ring‐opening polymerization. RCP_Et was prepared using RC_Et, which exhibits the lowest component mobility. The low component mobility is reflected in inferior mechanical strength and stretching ability in tensile stress tests compared to components with good (R=Me) and high (R=H) mobility. However, RCP_Et exhibited significantly higher stress and strain values than the corresponding covalently crosslinked polymers (CCP_Rs). These results indicate that a suitable component mobility substantially enhances the mechanical strength of RCPs. This behavior could serve as a guiding principle for the molecular design of advanced RCs. Stretching out: Rotaxane crosslinkers (RC_Rs) with two radically polymerizable vinyl groups were synthesized to evaluate the mobility of the components in determining the properties of rotaxane‐crosslinked polymers (RCP Rs). RCP_Et exhibits the lowest component mobility, as reflected in inferior mechanical strength and stretching ability of the RCP compared to those with components with good (R=Me) and high (R=H) mobility.