Crosslinking behaviors and mechanical properties of curable PDMS and PEG films with various contents of glycidyl methacrylate

The real-time curing behaviors and surface mechanical properties of two curable systems, polydimethylsiloxane (PDMS) and poly(ethylene glycol) (PEG) films containing different portions of glycidyl methacrylate (GMA), were investigated via various measurements for potential application as anti-fouling coatings. In these mixtures, methacryloxypropyl-terminated PDMS and poly(ethylene glycol)dimethacrylate were used as the difunctional crosslinkers, and GMA was employed as the epoxy component. During the coating process, UV irradiation generated network structures for both mixtures (PDMS-GMA and PEG-GMA), while they exhibited the different evolution of the elastic modulus with respect to the GMA content. It was found that a small portion of the crosslinkers formed at early stage has a dominant contribution to the overall film properties, leading to a small swelling ratio and large gel fraction. The indentation and scratch mechanical properties of the cured films were qualitatively well linked with the real-time rheological data for the curable mixtures acquired during the curing process.