Rotaxane Formation of Multicyclic Polydimethylsiloxane in a Silicone Network: A Step toward Constructing “Macro‐Rotaxanes” from High‐Molecular‐Weight Axle and Wheel Components

• Published in: Angewandte Chemie Vol. 135; no. 35
• Main Authors: Ebe, Minami, Soga, Asuka, Fujiwara, Kaiyu, Ree, Brian J., Marubayashi, Hironori, Hagita, Katsumi, Imasaki, Atsushi, Baba, Miru, Yamamoto, Takuya, Tajima, Kenji, Deguchi, Tetsuo, Jinnai, Hiroshi, Isono, Takuya, Satoh, Toshifumi
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 28-08-2023
• Subjects: Additives; Chemistry; Cyclic Polymers; Damping; Damping Performance; Leaching; Macro-Rotaxane; Polydimethylsiloxane; Polymers; Rotaxanes; Shafts (machine elements); Silicone Networks; Silicones; Topological Trapping; Trapping
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202304493

Rotaxanes consisting of a high‐molecular‐weight axle and wheel components (macro‐rotaxanes) have high structural freedom, and are attractive for soft‐material applications. However, their synthesis remains underexplored. Here, we investigated macro‐rotaxane formation by the topological trapping of multicyclic polydimethylsiloxanes (mc‐PDMSs) in silicone networks. mc‐PDMS with different numbers of cyclic units and ring sizes was synthesized by cyclopolymerization of a α,ω‐norbornenyl‐functionalized PDMS. Silicone networks were prepared in the presence of 10–60 wt % mc‐PDMS, and the trapping efficiency of mc‐PDMS was determined. In contrast to monocyclic PDMS, mc‐PDMSs with more cyclic units and larger ring sizes can be quantitatively trapped in the network as macro‐rotaxanes. The damping performance of a 60 wt % mc‐PDMS‐blended silicone network was evaluated, revealing a higher tan δ value than the bare PDMS network. Thus, macro‐rotaxanes are promising as non‐leaching additives for network polymers.
“Macro‐rotaxanes” which consist of high‐molecular‐weight axle and wheel components were constructed by in situ cross‐linking of linear polymers in the presence of multicyclic polymers. Extending the concept of topological trapping to multicyclic showed that multicyclic polymers with more cyclic units and larger ring sizes can be quantitatively trapped, with up to 50 wt % successfully topologically trapped as macro‐rotaxanes.