On the Generation of Polyether-Based Coatings through Photoinduced C,H Insertion Crosslinking

In this work, the synthesis of a photoreactive polyether and its subsequent photochemical attachment to various substrates is described. Poly(bisphenol A-co-epichlorohydrin) is chosen as an example for a technologically important class of polymers and modified in a polymer-analogous reaction with photoreactive benzophenone units. During brief UV activation, benzophenone forms reactive intermediates, which are able to formally insert into any aliphatic C,H bond, eventually forming a crosslinked polymer film. During the formation process the emerging polyether networks additionally bind to (practically) any organic molecule present at the substrate surface. This way in one reaction step directly a surface-attached polymer network is obtained. The examples, which are shown, include silane-covered oxidic surfaces and unmodified polyolefins. When appropriate masks are used, brief UV irradiation is sufficient to generate crosslinked, surface-attached polyether microstructures on a broad spectrum of substrate materials. The described strategy allows the generation of one-component polymer coatings from standard commodity polymers under very simple process conditions, which can be lithographically structured and covalently attached to a broad spectrum of substrates, comprising even chemically rather inert materials.