Journal of Applied Polymer Science, Vol.111, No.1, 87-93, 2009
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 H-1 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,,) of the copolymers were in the range of 1.1 x 10(4)-1.6 x 10(4) with polyclispersity 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. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 87-93, 2009
Keywords:copolymerization;functionalization of polymers;gel permeation chromatography (GPC);Lewis acid-mediated polymerization;1-octene;acidic alumina