Wang Chen, Mavila Sudheendran, Worrell Brady T, Xi Weixian, Goldman Trevor M, Bowman Christopher N
Department of Chemical and Biological Engineering, University of Colorado, UCB 596, Boulder, Colorado 80309, United States.
ACS Macro Lett. 2018 Nov 20;7(11):1312-1316. doi: 10.1021/acsmacrolett.8b00611. Epub 2018 Oct 16.
Polymers that possess dynamic covalent bonds activated at ambient conditions are ideal platforms for smart, responsive materials. Herein, a class of dynamic covalent polymerizations is developed based on the thiol-thioester exchange, that is, transthioesterification, reaction. Shifts in the equilibrium extent of the exchange reactions are deliberately utilized to drive the formation of oligomers and polymers. In particular, a series of AB and A-B monomers, including amino acid derivatives, were polymerized rapidly by catalytic amounts of mild bases in various organic solvents under ambient conditions. Thioester backbone oligopeptides, including cysteine and glycine, were obtained with an average repeating unit of four and a PDI of 1.8. Further, structurally dynamic hydrogels were obtained by such reactions between four-armed poly(ethylene glycol)-10000 based monomers in neutral water. These hydrogels showed dynamic, frequency-dependent flow behavior between sol and gel states.
在环境条件下具有活化动态共价键的聚合物是制备智能响应材料的理想平台。在此，基于硫醇-硫酯交换反应（即转硫酯反应）开发了一类动态共价聚合反应。通过刻意利用交换反应平衡程度的变化来驱动低聚物和聚合物的形成。特别地，一系列AB型和A-B型单体，包括氨基酸衍生物，在环境条件下于各种有机溶剂中通过催化量的温和碱快速聚合。得到了包含半胱氨酸和甘氨酸的硫酯主链寡肽，其平均重复单元为四个，多分散指数为1.8。此外，通过基于四臂聚乙二醇-10000的单体在中性水中进行此类反应，获得了结构动态水凝胶。这些水凝胶在溶胶和凝胶状态之间表现出动态的、频率依赖性的流动行为。
