The interaction of linear, amylose oligomers with iodine

Abstract A series of linear, amylose oligomers has been synthesized enzymically to yield samples having the number-average degree of polymerisation, D P n ¯ , in the range 22 to 134. The interaction of these materials with iodine has been studied. The wavelength of maximal absorption of the iodine complex, λ max , has been found to be related to D P n ¯ by the Langmuir isotherm: 1 / λ max ⁡ = 1.558 × 10 − 3 + 102.5 × 10 − 4 ( 1 / D P n ¯ ) . Differential, potentiometric titration of iodine has shown that the iodine-binding capacity of the linear oligomers is a function of both D P n ¯ and temperatures. The enthalpy of the iodine uptake has been measured, and found to be a function of D P n ¯ for values of D P n ¯