Study of Solution Properties of Poly(deamino-tyr-tyr carbonate hexyl ester) by Light Scattering and Viscometry in Dilute and Semidilute Regime

摘要

The structure and properties of poly(deamino-tyr-tyr carbonate hexyl ester), in dilute and semidilute solutions, were studied using static, dynamic light scattering, and viscometry. The overlap concentration, c* is determined by viscosity. The angular dependence of Zimm plots shows no downturn at low angles. In addition, bimodal distribution curves were computed from the quasielastic measurements. The radius of gyration and the second virial coefficient A^sub 2^ are found to be respectively 45.8 nm and 9.4 mol cm^sup 3^ g^sup -2^. The correlation and persistence lengths are discussed. The poly (deamino-tyr-tyr carbonate hexyl ester) or poly(DTH-carbonate) chain in THF, at T = 20° C, behaves as a wormlike chain with persistence length. The persistence length obtained using light scattering is compared with that obtained using viscosity with good agreement. These values obtained from these measurements reflect a high degree of local chain persistence. The reduced viscosity in dilute regime provides a value of apparent viscosity hydrodynamic radius three times lower than obtained by static light scattering. [PUBLICATION ABSTRACT]