Photopolymerization of methyl methacrylate using dye-sensitized semiconductor based photocatalyst

Photopolymerization of methyl methacrylate (MMA) was carried out using semiconductor (CdS) as a photocatalyst under visible light exposure. The influences of additives like eosin (dye) and triethylamine on the photochemical properties of semiconductor (CdS) particle and photopolymerization of MMA were studied. A 2–3% conversion was achieved on using only CdS as photocatalyst. On using an electron donor (Et3N) along with CdS however a conversion of up to 14% was reached. The molecular weight in this case however was low. On carrying with eosin dye along with CdS, up to 22% yield of the polymer was obtained. The polymer so obtained was characterized by GPC. Polydispersity was found to be in the range of 6–6.5 for the polymer obtained by using dye as sensitized semiconductor catalyst and 4–4.5 for the polymer obtained using only dye as catalyst. The free radical polymerization of MMA has been established with EPR spectra.