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

The radius of gyration 〈 S 2 〉 1/2, hydrodynamic radius R H, intrinsic viscosity [ η ], and second virial coefficient A 2 for cellulose tris(phenyl carbamate) (CTC) in tetrahydrofuran (THF) at 25 °C were determined in a wide range of molecular weights, 1.91 × 10 4 to 392 × 10 4, 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 〈 S 2 〉 1/2, R H, and [ η ] were analyzed by the established quasi-two parameter theory for the wormlike chain model to determine the molar mass M L per unit contour length and the persistence length q . On the other hand, results of A 2 and ∂ c/ ∂ Π were analyzed on the basis of the scaled particle theory for wormlike spherocylinders combined with the quasi-two parameter theory for A 2 to estimate the hard-core diameter d 0 and strength δ of the soft dispersion force of the CTC chain in THF. The value of M L [=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 d 0 [=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.