Alternating copolymers of functionalized α-methyl styrene monomers and maleic anhydride

Abstract

Alkyl and tertiary amine functionalized α-methyl styrene (AMS) monomers have been synthesized via reactive coupling of 3-isopropenyl-α,α-dimethylbenzyl isocyanate (TMI) with primary amines. Primary amines utilized include hexylamine, octadecylamine and N,N-dimethylethylenediamine to synthesize monomers, 3-hexyl-1-[1-(m-isopropenylphenyl)-1-methylethyl]urea (AMSC₆), 3-octadecyl-1-[1-(m-isopropenylphenyl)-1-methylethyl]urea (AMSC₁₈) and 3-(2-(dimethylamino)ethyl)-1-[1-(m-isopropenylphenyl)-1-methylethyl]urea (AMSDMA), respectively. The structures of these functionalized AMS monomers have been confirmed by ¹H-NMR, ¹³C-NMR and FT-IR. AMS, AMSC₆ or AMSC₁₈ was then successfully copolymerized with maleic anhydride (MalA) via free radical polymerization initiated by azobisisobutyronitrile to synthesize alternating copolymers. Free radical homopolymerizations of AMS, AMSC₆, AMSC₁₈ and MalA were performed to reveal no monomer conversion by gas chromatography and no formation of polymer chains by gel permeation chromatography (GPC). Alternating copolymers were characterized by GPC, ¹H-NMR, FT-IR and MALDI-TOF MS. Finally, post-polymerization modification of P[(AMSC₁₈)-a-(MalA)] by imidization of the MalA repeat unit with a primary amine was performed. This leads to the synthesis of alternating dual functionalized copolymers in an efficient and simple way.