Free radical solution copolymerization of n-octylacrylamide and maleic anhydride in a non polar solvent; Synthesis and characterization of a difunctional copolymer

A novel difunctional random copolymer of maleic anhydride (MA) and n-octylacrylamide (acrylamide-n-octyl, AAO) with both anhydride and acrylamide moieties was synthesized. The copolymer had a molecular weight by SEC of between 950 and 1900 and a polydispersity of between 1.0 and 4.0. The performance of initiators azo-isobutyronitrile (AIBN) and benzoyl peroxide (BPO) at varying concentrations in solvent o-xylene were compared at four different initial MA:AAO ratios (7:3, 5:5, 6:4 and 4:6). The molecular weight of the synthesized copolymers at 7.5 mol % initiator concentration increased proportionally with the conversion at a 5:5 monomer ratio, whereas copolymerization at other initiator concentration and monomer ratios revealed a non-linear behavior. Characterization of monomer and copolymer on the basis of H-1-NMR and C-13-NMR is also reported.