New surface-coating materials: electron-beam curing of some silicon-containing acrylates

A series of silicon-containing mono-, di-, tri- and tetraacrylates have been synthesized. The tetraacrylates and triacrylates cure at very low doses to give hard, flexible films possessing good solvent resistance properties. The diacrylates cured rapidly to give soft films, whereas the monoacrylates polymerized to give highly viscous fluids. A quantitative evaluation of rate of cure showed that the order of reactivity was diacrylate > triacrylate > monoacrylate. The presence of silicon appears to confer many special properties. These are ascribed to the silicon atom effecting enhanced conformational mobility of the polymer chains. The high reactivity of the di- and triacrylates may be due to the silicon acting as a site for ionization, leading to the production of initiating species.