Solution Properties of Cellulose Tris(phenyl carbamate). 1. Characterization of the Conformation and Intermolecular Interaction

Abstract

The radius of gyration 〈S2〉1/2, hydrodynamic radius RH, intrinsic viscosity [η], and second virial coefficient A2 for cellulose tris(phenyl carbamate) (CTC) in tetrahydrofuran (THF) at 25 °C were determined in a wide range of molecular weights, 1.91 × 104 to 392 × 104, by static and dynamic light scattering and viscometry. Furthermore, the osmotic compressibility ∂c/∂Π for isotropic THF solutions of CTC samples was measured at 25 °C by static light scattering over wide ranges of the polymer concentration. Data of 〈S2〉1/2, RH, and [η] were analyzed by the established quasi-two parameter theory for the wormlike chain model to determine the molar mass ML per unit contour length and the persistence length q. On the other hand, results of A2 and ∂c/∂Π were analyzed on the basis of the scaled particle theory for wormlike spherocylinders combined with the quasi-two parameter theory for A2 to estimate the hard-core diameter d0 and strength δ of the soft dispersion force of the CTC chain in THF. The value of ML [=1040 (±70) nm-1] estimated is consistent with the 3/2 helical conformation of CTC in the crystal of the CTC-methyl ethyl ketone complex, while the hard-core diameter d0 [=1.4 (±0.1) nm] is slightly smaller than the interchain spacing (=1.66 nm) of CTC in the same crystal. The value of q [=10.5 (±1) nm] for CTC is comparable to literature values of q for some other cellulose derivatives reported so far.