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 degrees C (water contact angle 28 degrees) and a hydrophobic surface at 45 degrees C (water contact angle 132 degrees). (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012.