Novel rubbery wound closures containing various proportions and molecular weights of polyisobutylene (PIB) and poly(2-octyl cyanoacrylate) [P(OctCA)] for potential clinical use were designed, synthesized, characterized, and tested. Homo-networks were prepared by crosslinking 3-arm star-shaped PIBs fitted with terminal cyanoacrylate groups, [O(PIB-CA)(3)], and co-networks by copolymerizing O(PIB-CA)(3) with OctCA using N-dimethyl-p-toluidine (DMT). Neat O(PIB-CA)(3), and O(PIB-CA)(3)/OctCA blends, upon contact with initiator, polymerize within seconds to optically transparent strong rubbery co-networks, O(PIB-CA)(3)-co-P(OctCA). Homo- and co-network formation was demonstrated by sol/gel studies, and structures and properties were characterized by a battery of techniques. The T-g of P(OctCA) is 58 degrees C by DSC, and 75 degrees C by DMTA. Co-networks comprising 25% O(PIB-CA)(3) (M-n=2400 g/mol) and 75% P(OctCA) are stronger and more extensible than skin. Short and long term creep studies show co-networks exhibit high dimensional stability and <6% creep strain at high loading. When deposited on porcine skin co-networks yield hermetically-adhering clear rubbery coatings. Strips of porcine skin coated with co-networks could be stretched and twisted without compromising membrane integrity. The co-network is nontoxic to L-929 mouse fibroblasts. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1640-1651