Simulation on the structure of AN-IA copolymers resulted from copolymerization in DMSO/H_2O

The reactivity ratio of itaconic acid (IA) and acrylonitrile (AN) is determined for free-radical copolymerization which is carried out in DMSO/H_2O: r_AN=0.405, r_IA=2.946. The relationship of conversion and molecular structure of P(AN-co-IA) copolymers, and the sequence distribution of P(AN-co-IA) copolymers for a given initial reaction condition are simulated by the use of computer. It has been shown that the composition of IA in the P(AN-co-IA) copolymers changes with different conversion according to the result of computer simulation. The majority of IA has been copolymerized in P(AN-co-IA) at the start reaction period, and the instantaneous IA mole fraction in copolymers becomes less and less with the proceeding of copolymerization. The average of sequence length in copolymer has an intense relation with the feed ratio of monomers, especially, for a less incorporation of IA, the average sequence length of AN decreases abruptly owing to the interruption of IA.