ABSTRACT
Phosphites form coordination complexes with metal ions, thereby changing the potential activity of the metal (58). In addition, some phosphite-metal complexes incorporated into polymers were active stabilizers. One particular study found that, in polyolefines containing high levels of catalyst residues, phosphites effectively improve the weathering resistance of the polymer by interacting with the metal residues (58). Pobedimskii et al. (26) reviewed the enhancement of the efficiency of organic phosphites in the presence of transition metal ions, in particular transition metal acetyl acetonates. They suggested the formation of new metal complexes with phosphite ligands, which effectively scavenge peroxyl radicals and decompose hydroperoxides. Prolonged induction periods of high-and low-density polyethylene stabilized with phosphites by factors of 2-7 were observed in the presence of various titanium and vanadium compounds.
