Thermo‐sensitive electrospun fibers prepared by a sequential thiol‐ene click chemistry approach

This manuscript describes a straightforward method to prepare stimuli‐responsive fibers by the combined technology of electrospinning and two facile thiol‐ene click chemistry processes: photo‐initialized thiol‐ene radical addition and thiol‐Michael nucleophilic addition. By controlling the molar ratio of poly((3‐mercaptopropyl)methylsiloxane) (PMMS) and the cross‐linker, triallyl cyanurate, PMMS‐based fibers can be partially photo‐crosslinked via UV illumination during electrospinning, to grant them the solvent‐resistant property, meanwhile leaving unreacted free mercapto groups on the surfaces, which could be further functionalized with stimuli‐responsive polymer brushes. To demonstrate the feasibility of this approach, a facile thiol‐Michael addition protocol between PMMS fibers with free thiol groups on the surfaces and maleimide‐terminated PNIPAM has been developed, which allows for the preparation of polysiloxane fibers with thermo‐responsive PNIPAM brushes on the surfaces. PMMS‐g‐PNIPAM fibers show thermo‐sensitive behavior to the environment, having a hydrophilic surface at 20°C (water contact angle ～28°) and a hydrophobic surface at 45°C (water contact angle ～132°). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012.