Mean-Square Radius of Gyration and Second Virial Coefficient of Poly(diisopropyl fumarate) in Dilute Solution

Abstract

The mean-square radius of gyration <S2> and second virial coefficient A2 were determined from light scattering measurements for 13 samples of poly(diisopropyl fumarate) (PDiPF), each with the fraction of racemo diads fr=0.22, in a range of weight-average molecular weight from 4.02×104 to 8.59×105 in tetrahydrofuran at 30.0 °C. From a simultaneous analysis of the present data for <S2> and A2 on the basis of the Kratky–Porod (KP) wormlike chain with excluded volume, the KP model parameters for PDiPF, i.e., the stiffness parameter λ−1 and the shift factor ML are determined to be 113 Å and 89 Å−1, respectively, the ML value being consistent with that estimated on the basis of chain conformations of PDiPF. The λ−1 value indicates that PDiPF is stiffer than typical flexible polymers but not so stiff as typical semiflexible polymers such as poly(n-hexyl isocyanate).