Chain dimension of polystyrene-like hyperbranched polymers with various chain end groups in THF

A hyperbranched polymer (HPS-DC) synthesized using N,N-diethylamino -dithiocarbamoylstyrene as an inimer and a hyperbranched poly(4-methylstyrene) (HPS-H) prepared by hydrogenation of the HPS-DC are characterized in tetrahydrofuran (THF) solutions by static and dynamic light scattering measurements. The experimental values of z-averaged mean-square radius of gyration (<S²>_z^1/2) and hydrodynamic radius (R_H) of the HPS-H have smaller dimensions than those of the linear polystyrene (PS) at the same degree of polymerization (N_w), whereas the R_H of the HPS-DC in the region of N_w < 700 is larger than that of the linear PS at the same N_w. The N _w-dependence of <S²>_z^1/2 and R_H for the HPS-H are described by a randomly trifunctional branched polymer model with the molecular weight per a branch point (4.55 × 10 ³ g/mol) and the chain dimensions of the linear PS in THF at 25 °C.