EFFECT OF BRANCHING OF AMYLOPECTIN ON COMPLEXATION WITH IODINE AS STERIC HINDRANCE

The structure of an amylopectin-iodine coloured complex has been inves tigated by small-angle X-ray scattering. The amylopectin shows the sca ttering profile of a branched polymer with persistent chain and curvat ure. The complexation of amylopectin with iodine induces different str uctural changes compared with those found for linear polymers, such as amylose and partially formalized poly(vinyl alcohol). This suggests t hat the presence of branch points in the amylopectin molecule contribu te to steric hindrance in suppressing the structural change induced by the formation of polyiodine in the polymer chains.