Dilute-Solution Properties of Polystyrene Polymacromonomer Having Side Chains of over 100 Monomeric Units.

Static and dynamic light scattering and viscosity measurements were made on 12 samples of polymacromonomer F110 consisting of polystyrene with 113 styrene units in each side chain to determine the z-average mean-square radius of gyration, the hydrodynamic radius, and the intrinsic viscosity in cyclohexane at 34.5 °C (the theta temperature) and toluene at 15.0 °C as functions of weight-average molecular weight M_w. Small-angle X-ray scattenng experiment was also performed for one sample in the two solvents. The dependence of the three measured properties on Mw in the range 1.9 x 10⁵-1.3 x 107 studied were consistently explained by available theories for the wormlike chain with ML (the molar mass per unit contour length) = 45500nm^-1, λ^-1 (the stiffness parameter) = 80nm (in cyclohexane) or 155 nm (in toluene), and d (the chain diameter) = 16-26 nm (depending on the kind of solvent and measured property) when the end effect arising from side chains near the main-chain ends was taken into account. The side-chain length dependence of/λ-1, examined with the aid of previous data for three polystyrene polymacromonomers with shorter side chains of 15, 33, and 65 styrene units, was found to be almost quantitatively explained by the theory of Nakamura and Norisuye [Polym J., 33, 874 (2001)]. That of d was also discussed in relation to the end-to-end distance of a wormlike side chain [ABSTRACT FROM AUTHOR]