Table of Contents
ISRN Physical Chemistry
Volume 2012, Article ID 942398, 7 pages
http://dx.doi.org/10.5402/2012/942398
Research Article

Ag(I) Catalyzed Grafting of Acrylonitrile onto Gum Arabic by Ce(IV) in H 2 S O 4 Medium: A Kinetic Study

Department of Chemistry, University College of Sciences, Osmania University, Hyderabad 500007, A.P., India

Received 1 August 2011; Accepted 5 September 2011

Academic Editor: T. Pasinszki

Copyright © 2012 Geeta Thota and P. Srinivas. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Grafting of Acrylonitrile (AN) onto water-soluble polymer Gum arabic (GA) was carried out using ceric ammonium sulfate [Ce(IV)] as initiator in the presence and absence of Ag(I) in H2SO4 medium at 313 K. The rate of oxidation ( 𝑅 o x i ), rate of grafting ( 𝑅 g ), and grafting efficiency (GE) were determined for catalyzed and uncatalyzed grafting and suitable mechanism was proposed to explain the observed results. No homopolymerization in the absence of GA indicates that the polymer obtained is purely a graft copolymer. A probable mechanism involving the formation of Ag(I)-GA adduct followed by its oxidation with Ce(IV) to give Ag(II)-GA adduct, and its decomposition to give initiating radicals is proposed to explain the observed results. The graft polymer was characterized using Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction, and scanning electron microscopy (SEM) considering GA as reference.