Copolymerization of styrene and methyl methacrylate mediated by iron wire/N,N,N′,N′-tetramethyl-1,2-ethanediamine as catalyst in the presence of air

Random copolymers of P(MMA-co-styrene) were synthesized via single electron transfer-living radical polymerization (SET LRP) at 25 °C in N,N-dimethylformamide (DMF) and benzene using CCl4 as initiator and Fe(0) wire/N,N,N′,N′-tetramethyl-1,2-ethanediamine (TMEDA)/hydrazine (NH2NH2) complexes as catalyst in the presence of air. Fe(0) wire-mediated single electron transfer-living radical copolymerization of MMA and styrene represented a robust and versatile technique to synthesize the well-defined copolymers. The copolymerization rate was faster in DMF than in benzene, as determined by the apparent rate constants. The results showed that the copolymerization followed first-order kinetics model in the presence of polar DMF and non-polar benzene. The molecular weights increased linearly with the increase of monomer conversion with a narrow polydispersity index when the conversion was beyond 25 %. The polarity and the quantity of solvent had significant effects on the polymerization, and the apparent rate constants were 1.28 × 10−4, 1.21 × 10−4, and 9.23 × 10−5 s−1 in the order of DMF amount, 5, 10, and 15 mL. The conversion increased from 29.3 to 48.5 % and the polydispersity index (PDI) changed from 1.24 to 1.21 with [CCl4]0/[TMEDA]0 molar ratio changing from 1:0.5 to 1:5. The chain extension experiment demonstrated that the copolymerization exhibited a living characteristic.