Biocompatible polymeric systems: Copolymerization of 4-methacryloyloxy-acetanilide with 2-hydroxyethyl-methacrylate

Soluble copolymers of 4-methacryloyloxy-acetanilide (M), an acrylic derivative of paracetamol, with 2-hydroxyethyl-methacrylate (H) were prepared by free radical polymerization in DMF solution at 50°C, using 2,2′-azobisisobutyronitrile (AIBN) as initiator. The reactivity ratios of both monomers were determined by the application of conventional linearization methods suggested by Fineman-Ross and Kelen-Tudos. The results obtained make clear that this system copolymerizes at random with the reactivity ratios r_m = 2.15 ± 0.05 and r_H = 0.90 ± 0.10. The microstructure of copolymer chains is described on the basis of the first order Markov statistics. The copolymer glass transition temperatures were determined calorimetrically and the variation of T_g with the copolymer composition is discussed according to modern methods, considering the sequence distribution of monomeric units along the copolymer chains. Also the T_g of the corresponding homopolymers were determined giving the values of T_g(M) = 471 K and T_g(H) = 358 K.