Fast UV‐ and Visible Light Induced Polymer Network Formation Using Carbene Mediated CH‐insertion Based Crosslinking (CHic) Via Nitrophenyl Diazo Esters

Abstract

AbstractThe synthesis and characterization of highly photosensitive coatings containing a diazo‐based crosslinker that exhibits high photoreactivity in the near‐visible UV and toward sunlight is present. Nitrophenyl diazo ester (nitroPEDAz) moieties are incorporated into polymer chains via free radical polymerization and generate upon irradiation carbenes, which undergo a CH insertion‐based crosslinking (CHic) reaction. The copolymers are deposited onto substrate surfaces through known coating techniques and then activated to form polymer networks and simultaneously attach covalently to the surfaces if CH groups are available. It is demonstrated that very low light doses on the order of 20 mJ cm−2 are sufficient to generate surface‐attached networks and that the copolymer can be patterned photolithographically into defined structures on a broad spectrum of substrates using UV‐ and natural sunlight. Even a few seconds of sunlight exposure are sufficient to crosslink and surface‐attach the film.