Phase transfer catalysed copolymerization (Kinetics and mechanism of copolymerization of acrylonitrile and styrene initiated by PDS - benzyltriphenylphosphonium chloride initiator system under biphase condition)

The Phase–transfer radical copolymerization of acrylonitrile (AN) and styrene (ST) with benzyl-triphenylphosphoniumchloride was investigated in K2S2O8 aqueous-organic biphase system at 65°± 0.1°C and under nitrogen atmosphere. The rate of copolymerization was expressed as the combined terms of benzyl-triphenylphosphonium ion and peroxydisulphate ion in the aqueous phase rather than the fed concentration of catalyst and K2S2O8. The effects of varying [AN/ST], [ K2S2O8],[QX],[H +],ionic strength of the medium, and the temperature on the rate of copolymerization (Rp) have also been studied. Rp is found to be proportional to [AN/ST]1,[ K2S2O8] 0.5 and [QX]1. Based on the kinetics results, a mechanism involving initiation by phase transferred S2O8 2is proposed.