SynopsisThe radical copolymerization of acrylonitrile with 2-hydroxyethyl-(HEMA) and 2-hydroxypropyl-methacrylate (HPMA) has been studied in two media: dimethylformamide (DMF) and dimethylsulfoxide (DMSO), at 60OC. Copolymer composition was determined from the hydroxyl content and reactivity ratios were calculated by the Kelen-Tudos method. The values of ri and r-2 computed by the integrated and the Kelen-Tiidos methods have been compared. A strong influence of the solvent on the reactivity ratios, particularly on r2 (HEMA or HPMA), has been observed. The copolymers prepared in DMSO are richer in hydroxyalkyl acrylates than those prepared in DMF. This effect may be attributed to preferential monomer solvation and the stability of the growing radicals. The influence of hydroxyalkyl acrylate comonomer on the properties of acrylonitrile copolymers (intrinsic viscosity and thermal behavior) are also discussed.