Effect of reaction medium on copolymerization of acrylonitrile and methyl acrylate

Abstract

AbstractThe copolymerization of acrylonitrile (AN) with methyl acrylate (MEA) has been investigated in three types of polymerization, i.e., emulsion polymerization in water with a water‐soluble initiator, suspension polymerization in water with an oil‐soluble and water‐insoluble initiator, and solution polymerization in dimethyl sulfoxide (DMSO). Monomer reactivity ratios at 50°C. for AN and MEA are found to be r1 = 0.78 ± 0.02, r2 = 1.04 ± 0.02 in emulsion polymerization; r1 = 1.02 ± 0.02, r2 = 0.70 ± 0.02 in DMSO solution polymerization; r1 = 0.75 ± 0.05, r2 = 1.54 ± 0.05 in suspension polymerization. The large differences found in the reactivity ratios may be attributed to the different ratio of concentration of two monomers in the loci of polymerization. Chemically, AN is somewhat more reactive than MEA as shown by the reactivity ratios in DMSO. In the case of the suspension polymerization, the MEA/AN ratio in the polymer particles in which polymerization occurs may be higher than that in the total phase. Experimental results of the emulsion polymerization show that the emulsion polymerization of AN occurs both in the particles and in water. In addition, rates of the copolymerization of AN with MEA have also been investigated.