title: Mechanochromism and Mechanical-Force-Triggered Cross-Linking from a Single Reactive Moiety Incorporated into Polymer Chains.
abstract: Incorporation of small reactive moieties, the reactivity of which depends on externally imposed load (so-called mechanophores) into polymer chains offers access to a broad range of stress-responsive materials. Here, we report that polymers incorporating spirothiopyran (STP) manifest both green mechanochromism and load-induced addition reactions in solution and solid. Stretching a macromolecule containing colorless STP converts it into green thiomerocyanine (TMC), the mechanically activated thiolate moiety of which undergoes rapid thiol-ene click reactions with certain reactive C=C bonds to form a graft or a cross-link. The unique dual mechanochemical response of STP makes it of potentially great utility both for the design of new stress-responsive materials and for fundamental studies in polymer physics, for example, the dynamics of physical and mechanochemical remodeling of loaded materials.
authors.affiliation: Department of Chemistry, College of Chemistry and Engineering, Xiamen University, 422 South Siming Road, Xiamen, Fujian, 361005, P.R. China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, College of Chemistry and Engineering, Xiamen University, 422 South Siming Road, Xiamen, Fujian, 361005, P.R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Chemistry, College of Chemistry and Engineering, Xiamen University, 422 South Siming Road, Xiamen, Fujian, 361005, P.R. China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Chemistry, College of Chemistry and Engineering, Xiamen University, 422 South Siming Road, Xiamen, Fujian, 361005, P.R. China.
authors.forename: Yanqun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry, College of Chemistry and Engineering, Xiamen University, 422 South Siming Road, Xiamen, Fujian, 361005, P.R. China.
authors.forename: Yuanze
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Chemistry, College of Chemistry and Engineering, Xiamen University, 422 South Siming Road, Xiamen, Fujian, 361005, P.R. China. wgweng@xmu.edu.cn.
authors.forename: Wengui
authors.initials: W
authors.lastname: Weng
authors.affiliation: Department of Chemistry, University of Liverpool and Donnan Lab, G31, Crown St., Liverpool, L69 7ZD, UK.
authors.forename: Roman
authors.initials: R
authors.lastname: Boulatov
keywords: cross-linking; mechanochromism; mechanophores; polymers; spirothiopyran