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Polymerisation of methyl acrylate (MA) initiated by O 2 -ascorbic acid (AA)-Cu 2+ system was studied in aqueous medium at 40°C. The rate of polymerisation R p , was found to increase, remain constant, and then decrease with increasing [Cu 2+ ]. R p was found to depend on [Cu 2+ ] 0,6 , [AA] 0 , [O 2 ] 0,6 , and [MA] 1,3 in the increasing region, on [Cu 2+ ] 0 , [AA] 0 , [O 2 ] 0,6 , and [MA] 1,6 in the constant region and on [Cu 2+ ] -0,9 , [AA] 0 , [O 2 ] 0,7 , and [MA] 2,0 in the decreasing region. Rate laws were derived assuming a plausible reaction mechanism for the different regions. R p increased with ionic strength and decreased with [H 2 SO 4, ]. An initial increase, then steady state followed by a decrease in rate with temperature was noticed in the range 25-55°C. k p /k t ½ values were calculated and compared with literature values. Chain lengths were determined viscometrically.

Oxygen as a promoter of radical polymerisation of ethyl acrylate was studied in the aqueous medium. Cu2+ was chosen as the catalyst for the ascorbic acid (AA)—02 redox reaction, constituting a three component initiating system. The rate of polymerisation, Rp, was observed to increase, remain constant and then decrease with increasing [Cu2+]. Rp increased with [O2] upto ∼ 6.5 × 10−4M and thereafter remained constant. [AA] > 1.2 × 10−3M did not influence the rate. Rp always increased with monomer [M] at fixed [Cu2+], [O2] and [AA]. However, the order with respect to [M] increased with increasing [Cu2+]. The rate of polymerisation increased with ionic strength, μ and decreased with [H2SO4]. There was an initial increase in Rp followed by a decrease with increasing temperature. Conditions were identified where Rp depended only on [Cu2+] and [M] or [M] only for industrial exploitation. Kinetic chain length of the polymers obtained under various experimental conditions were determined viscometrically.

The polymerization of acrylonitrile (AN) initiated by oxygen-ascorbic acid (AA)-ferric ion system was studied in dil. HNO3 at 40°. The rate of polymerization, Rp, was found gravimetrically. In the [Fe3+] range, (2–5 × 10−5 M, Rp was proportional to [AN]1.5 ± 0.05, [O2]0.5 ± 0.02 [AA]0 and [Fe3+]0; for [Fe3+] = (5–30) × 10−5 M, it was proportional to [AN]1.8 ± 0.05, [O2]0.6 ± 0.02, [AA]0 and [Fe3+]−0.9 ± 0.05. A plausible reaction scheme is proposed and rate law presented to explain these results. Rp increased with ionic strength and [HNO3] (up to ∼0.25 M). An initial rate increase with temperature followed by a decrease was noticed. Chain lengths of the polymers were determined viscometrically.

Methyl methacrylate was polymerized in aqueous medium initiated by a copper(II)-ascorbic acidoxygen system at 40°C and a kinetic study of the reaction is presented. The rate of polymerization, Rp showed an increase, constancy and then a decrease with increase in the [Cu2+]. The order with respect to [Cu2+] was 0.5 in the rate increase region. The order in monomer concentration changed gradually from 1.0 to 2.0 with increase in [Cu2+]. Rp became independent of ascorbic acid (AA) concentration and oxygen concentration at high concentrations. These results indicate that termination by mutual interaction of chain radicals predominates at low [Cu2+] while termination was exclusively by metal ions at high [Cu2+]. Rp was also observed to increase with temperature and ionic strength and to K p K t 1 2 value was calculated and compared with literature values. Chain lengths were determined by viscometry for the polymers obtained under various experimental conditions.