Novel tetra-functional hydrolyzing monomers were prepared from the reaction of TEOS and select alkene-containing alcohols, ethylene glycol vinyl ether or 2-allyloxy ethanol, and combined with trimethylolpropane tris(3-mercaptopropionate) (tri-thiol) in a thiol-ene “click” polymerization reaction to produce clear, colorless thiol-ene networks using both radiation and thermal-cure techniques. These networks were characterized for various mechanical characteristics, and found to posses T_g’s (DSC), hardness, tack, and thermal stability (TGA) consistent with their molecular structures. A new ene-modified urethane oligomer was prepared based on the aliphatic polyisocyanate Desmodur^® N 3600 and added to the thiol-ene hydrolyzable network series in increasing amounts, creating a phase-segregated material having two T_g’s. An increase in water absorption in the ene-modified urethane formulations leading to a simultaneous increase in the rate of hydrolysis was supported by TGA data, film hardness measurements, and an NMR study of closely related networks. This phenomenon was attributed to the additional hydrogen bonding elements and polar functionality brought to the film with the addition of the urethane segment. SEM was utilized for visual analysis of topographical changes in the film’s surface upon hydrolysis and provides support for surface-driven erosion. Coatings prepared in this study are intended for use as hydrolyzing networks for marine coatings to protect against ship fouling. Full article

“Click” chemistry has become an efficient avenue to unimolecular polymeric nanoparticles through the self-crosslinking of individual polymer chains containing appropriate functional groups. Herein we report the synthesis of ultra-small (7 nm in size) polymethyl methacrylate (PMMA) nanoparticles (NPs) by the “metal-free” cross-linking of PMMA-precursor chains prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization containing b-ketoester functional groups. Intramolecular collapse was performed by the one-pot reaction of b-ketoester moieties with alkyl diamines in tetrahydrofurane at r.t. (i.e., by enamine formation). The collapsing process was followed by size exclusion chromatography and by nuclear magnetic resonance spectroscopy. The size of the resulting PMMA-NPs was determined by dynamic light scattering. Enamine “click” chemistry increases the synthetic toolbox for the efficient synthesis of metal-free, ultra-small polymeric NPs. Full article