This article presents the results of TMC and DMC polymerization with the use of acetylacetonates of low-toxic metals: iron, zinc, and zirconium. Zinc (II) acetylacetonate proves to be a very good initiator of homopolymerization. The reaction carried out with the use of this initiator at 110 degrees C is very rapid and of high yield. Using both zinc and iron (III) acetylacetonates, as well as the zirconium (IV) one, in high temperatures it is possible to obtain PTMC possessing high molecular mass, thus ensuring optimization of the relation between the duration of the polymerization and its yield. A strong influence of thermal degradation on the course of the reaction has been observed, particularly at 160 degrees C, with the use of Fe(acac)(3) as the initiator. DMC polymerization proceeds much more slowly when initiated by iron and zinc acetylacetonates. A high conversion of the monomer is obtained in this case as well. The relation between the molecular mass of the obtained PDMC and the conversion of the monomer is directly proportional; however, those masses, determined on the basis of polystyrene standards, are much lower than those estimated theoretically. (c) 2005 Wiley Periodicals, Inc.