Synthesis of new ionic crosslinked polymer hydrogel combining polystyrene and poly(4-vinyl pyridine) and its self-healing through a reshuffling reaction of the trithiocarbonate moiety under irradiation of ultraviolet light

A new ionic crosslinked polymer hydrogel was achieved by the strategy of ionically crosslinking ,-dibromide terminated polystyrene (Br-PS-Br) with poly(4-vinyl pyridine) (P4VP) which was synthesized by reversible addition-fragmentation chain transfer polymerization using a chain transfer agent containing a trithiocarbonate moiety. The moiety of trithiocarbonate was introduced into the crosslinked network to show the self-healing characteristics. The chain structure and components of Br-PS-Br and P4VP were characterized through H-1 NMR, gel permeation chromatography, Fourier transform IR spectroscopy and elemental analysis. The P4VP (M-n=25300gmol(-1)) chains were crosslinked with Br-PS-Br (M-n=2000gmol(-1)) through the quaternization reaction to form a polymer network which was further crosslinked in acetonitrile by irradiation of UV light to fabricate a hydrogel. Such a hydrogel of P4VP/Br-PS-Br cut by a razor blade can be rapidly (1h) and repeatedly (three times) healed through a reshuffling reaction of the trithiocarbonate moiety under irradiation by UV light. (c) 2018 Society of Chemical Industry