Synthesis and properties of metal complexes of radiation grafted carboxyl containing copolymers

Metal complexes of copolymers based on polyacrylic acid radiation grafted onto films of low density polyethene were prepared by complex‐forming with solutions of salts of FeCl₃.6H₂O, CuCl₂.2H₂O, CoCl₂.6H₂O, NiCl₂.6H₂O, VOSO₄.5H₂O, Na₂MoO₄.2H₂O, Na₂WO₄.2H₂O, and NH₄VO₃. The introduction of metal ions was found to depend mainly on the degree of grafting of acrylic acid and was from 0.5 to 5.0 mass%. These complexes were characterized by IR, UV spectroscopy, and EPR. The moisture content of the materials obtained changed linearly with the degree of grafting of acrylic acid and was from 9.0 to 80.0%. The introduction of the MoO₂²⁺ and WO₂²⁺ towards carboxylic groups lead to increasing the thermal stability of the metal complexes of the copolymers compared to the initial grafted films. The modified acrylate copolymers were studied in reactions of catalytic oxidation of cyclohexene. The activities of the complexes obtained towards cyclohexene epoxidation can be arranged in the following order: PAA–MoO₂²⁺ > PAA–VO²⁺ > PAA–VO > PAA–WO₂²⁺, while for the reaction of cyclohexene hydroxylation the order was—PAA–Co²⁺ > PAA–Cu²⁺ > PAA–Fe³⁺ > PAA–Ni²⁺. The contents of cyclohexene oxide and 2‐cyclohexene‐1‐ol reached 38.5% and 7.5%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1658–1665, 2006