The photopolymerization of methyl methacrylate (NIMA) was carried out using semiconductor (CdS) as a photocatalyst in the presence of solar radiation. The photopolymerization of MMA has been achieved (6-9% conversion) on exposure to solar radiation for a stipulated time period in the intensity range 450-800 W/m(2). A little higher conversion (similar to 11%) with higher molecular weight was achieved in the presence of US as a photocatalyst. In the presence of an electron donor like Et3N along with the photocatalyst (CdS), the highest conversion of 26-45% with lower molecular weight was achieved. The polymers have been characterized by viscometry and gel permeation chromatography (GPC). (c) 2005 Published by Elsevier B.V.