Synthesis, Characterization and Determination of Reactivity-Ratios of Acrylamide-Methacrylate Copolymers

Abstract

Free radical copolymerisation of acrylamide (A) with five methacrylates,
namely methacrylate (MM), ethyl methacrylate (EM), isopropyl
methacrylate (IPM), butyl methacrylate (BM) and hexyl methacrylate
(HM) were carried out in the presence of 2,2' -azobisisobutyronitrile
(AIBN) in dimethylformarnide (DMF) at 60°C. The percentage compositions
of the copolymers were established by elemental analysis. The complymers
were characterized by IR, ¹H-NMR and ¹³C-NMR studies. The
copolymerization reactivity ratios (r) were determined by both FinemannRoss
(FR) and Kelen-Tudos (KT) methods. The product of r₁ (methacrylate)
and r₂ (A) remains less than unity indicating that all these copolymers
are weakly ordered with a predominantly random distribution of the
monomeric units in the polymer chain. The order of reactivity of the alkyl
methacrylates towards acrylarnide radical is MM > EM > IPM > BM > HM.