A study on sorbitol-ceric ion initiated polymerization of acrylonitrile

The polymerization of acrylonitrile (M) initiated by the sorbitol (R)-Ce(IV) redox system has been studied in sulphuric acid in the range 30–40° under nitrogen. At moderately high concentrations of Ce(IV) (0.00015-0.02 M), the rate of polymerization (R_p) is proportional to $\text{M}\text{]}{}^{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ and $\text{R}\text{]}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and the rate of Ce(IV) disappearance is proportional to R] and Ce(IV)]. At lower concentration of Ce(IV) (0.00005–0.00015 M) R_p is proportional to M], R]^1/2 and Ce(IV)]^1/2 and rate of Ce(IV) disappearance is proportional to R] and Ce(IV)]. The effects of certain salts, acid, solvent and temperature on both rates have been investigated. A kinetic scheme involving mutual termination has been proposed and various rate and energy parameters evaluated. At still higher concentration of Ce(IV) (0.02 M), a linear mode of termination seems to operate.