• hydrogels;
  • interpenetrating networks (IPN);
  • mechanical property;
  • modulus;
  • networks;
  • polyethers;
  • poly(ethylene glycol);
  • swelling degree;
  • thiol–ene click chemistry;
  • UV curing


Poly(ethylene glycol) (PEG)-diallyls, ranging from 2 to 8 kDa, were successfully reacted with a trifunctional thiol crosslinker via thiol–ene coupling reaction to construct four different primary PEG hydrogels. These systems were used as scaffolds for the preparation of a library of sequential interpenetrating networks (SeqIPNs). The solid content of the secondary networks varied between 21 and 34% and was dependent on the length of the absorbing PEGs. The gel fractions for the IPNs were above 85%. Additionally, the lowest degree of swelling was found for the IPN based on 2-kDa PEG (315%), whereas the 8-kDa PEG IPN exhibited a value of 810%. The SeqIPN strategy facilitated hydrogel systems that cover a larger domain of tensile modulus (192–889 kPa) when compared with single hydrogel networks (175–555 kPa). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013