COPOLYMERS DERIVED FROM 4-NITROPHENYL METHACRYLATE (NPMA) AND METHYLMETHACRYLATE (MMA) - SYNTHESIS, CHARACTERIZATION, AND REACTIVITY RATIOS

The free radical copolymerization of 4-nitrophenyl methacrylate (NPMA) with methylmethacrylate (MMA) in 2-butanone was carried out with diff erent mole ratios of NPMA and MMA. The resulting copolymers were chara cterized by spectral studies. The molecular weights of the copolymers were determined by gel permeation chromatography and both number avera ge (M-n) and weight average (M-w/ molecular weights lie in the range o f 1.7-1.9 x 10(4) and 3.2-3.6 x 10(4), respectively. The copolymer com position was evaluated by H-1 NMR spectroscopic technique. The reactiv ity ratios of the monomers in the copolymer were calculated by Fineman -Ross, Kelen-Tudos and extended Kelen-Tudos methods. The product of th ese values are close to each other (0.73-0.80) and suggest a random ar rangement of monomers in the copolymer chain. Thermal properties of th ese systems investigated by TG and DSC indicate that the decomposition of all the copolymers occurs in the temperature range 175 degrees C-5 35 degrees C.