Methyl acrylate/1‐octene copolymers: Lewis acid‐mediated polymerization

Copolymerization of methyl acrylate (MA) with 1‐octene (1‐Oct) was conducted in the presence of free radical initiator, 2,2′‐azobis(2‐methylpropionitrile) (AIBN) using heterogeneous Lewis acid, acidic alumina. The polymers obtained were transparent and highly viscous liquids. The copolymer composition calculated from ¹H NMR showed alkene incorporation in the range of 10–61%. The monomodal nature of chromatographic curves corresponding to the molecular weight distribution in gel permeation chromatography (GPC) further confirmed that the polymers obtained are true copolymers. The number–average molecular weights (M_n) of the copolymers were in the range of 1.1 × 10⁴–1.6 × 10⁴ with polydispersity index of 1.75–2.29. The effects of varying the acidic alumina amount, time of polymerization, and monomer infeed on the incorporation of 1‐Oct in the polymer chain were studied. Increased 1‐Oct infeed led to its higher inclusion in the copolymer chain as elucidated by NMR. DEPT‐135 NMR spectral analysis was used to explicate the nature of arrangement of monomer sequences in the copolymer chain. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009