Metal chelates in vinyl polymerization: Kinetics and mechanism of acrylonitrile polymerization initiated by Cu(II) imine complexes

Abstract

AbstractThe free radical polymerization of acrylonitrile (AN) initiated by Cu(II) 4‐anilino 2‐one [Cu(II) ANIPO] Cu(II), 4‐p‐toluedeno 3‐pentene 2‐one [Cu(II) TPO], and Cu(II) 4‐p‐nitroanilino 3‐pentene 2‐one [Cu(II) NAPO] was studied in benzene at 50 and 60°C and in carbon tetrachloride (CCl4), dimethyl sulfoxide (DMSO), and methanol (MeOH) at 60°C. Although the polymerization proceeded in a heterogeneous phase, it followed the kinetics of a homogeneous process. The monomer exponents were ≥2 at two different temperatures and in different solvents. The square‐root dependence of Rp on initiator concentration and higher monomer exponents accounted for a 1:2 complex formation between the chelate and monomer. The complex formation was shown by ultraviolet (UV) study. The activation energies, kinetics, and chain transfer constants were also evaluated.