Halide anions have been used as complexing ligands in iron-mediated ATRP, in both direct and reverse ATRP. In direct ATRP, iron(II) bromide complexed with ammonium and phosphonium chloride, bromide or iodide salts has been shown to catalyze the polymerization of both styrene and (meth)acrylates in a controlled manner under appropriate conditions. The experimental molecular weights increased linearly with monomer conversion and were close to the calculated

Controlled/"living" free radical polymerization (CLRP) is a field that has been expanding continuously during the last decade, as the method allows for the preparation of well-defined polymers under much less demanding conditions than the ionic procedures. Many CLRP systems have been developed, but all of them rely on an equilibrium between active and dormant species. The present paper briefly reviews the fundamentals and the main approaches of CLRP.

(Vinyl acetate)-terminated polystyrene macromonomers (VAc-PSt-I) were synthesized by free-radical polymerization of styrene in the presence of vinyl iodoacetate (VAcI) as a chain transfer agent. Macromonomers with functionality close to unity were obtained, which were characterized by 1H NMR and size exclusion chromatography (SEC). No branching or incorporation of VAcI was noticed. The chain transfer constant of VAcI was determined by an integral

The free-radical copolymerization of methyl methacrylate (MMA) with styrene (St) in the presence of 2-mercaptoethanol (ME) was investigated in order to obtain w-hydroxy oligomers with random copolymer-type chains of various compositions and molecular weights. Polymerizations at three different MMA/St molar ratios were carried out, while keeping constant the ME/monomer ratio. Monomer mixtures richer in MMA than in St were employed in order to attempt