Copolymerization of N-(4-carboxyphenyl) itaconimide or N-(4-carboxyphenyl) itaconamic acid with methyl methacrylate

摘要

This paper describes the synthesis and characterization of N-(4-carboxyphenyl) itaconarnic acid (CPA) and N-(4-carboxyphenyl) itaconimide (CPI) obtained by reacting itaconic anhydride with p-aminobenzoic acid. Structural and thermal characterization of CPA and CPI was done using H-1-NMR, FTIR, and differential scanning calorimetry (DSC). Copolymerization of CPA or CPI with methyl methacrylate (MMA) in solution was carried out at 60 degrees C using azobisisobutyronitrile as an initiator and dimethyl acetamide or THF as solvent. Feed compositions having varying mole fractions of CPA or CPI ranging from 0.05-0.20 or 0.1-0.5 were taken to prepare copolymers. Copolymerizations were terminated at low percentage conversion. Structural characterization of copolymers was done by H-1-NMR and elemental analysis. Copolymer composition was determined using percentage nitrogen content. The reactivity ratios were r(1) (MMA) = 0.68 +/- 0.06 and r(2) (CPl) = 0.46 +/- 0.06. The intrinsic viscosity [eta] was determined using an Ubbelohde suspension level viscometer. [eta] decreased with increasing mole fraction of N-(p-carboxyphenyl) itaconimide or N-(p-carboxyphenyl) itaconamic acid in copolymers. Glass transition temperature and thermal stability of the copolymers were determined using DSC and thermogravimetric analysis, respectively. The glass transition temperature (T-g) as determined from DSC scans increased with increasing amounts of CPA or CPI in copolymers. A significant improvement in the char yield was observed upon copolymerization. (c) 2005 Wiley Periodicals, Inc.