Solution properties of near-monodisperse poly(a-methylstyrene) chains in the moderate solvent n-butyl chloride were investigated by a combination of static and dynamic light scattering and intrinsic viscosity measurements. These data allow the determination of the radii of gyration (Ro) as well as equivalent sphere radii: the hydrodynamic radius (RH), the viscometric radius (Rv), and the thermodynamic radius (RT) (defined below). Ratios of these various radii allow a comparison between solution properties of poly(amethylstyrene) in n-butyl chloride and those of other polymer/solvent systems, as well as with theoretical predictions. Whereas RG/RH values are intermediate, as expected, between those normally found in good solvents or at the 8 state, the average value of Rv/RH = 1.186 is substantially larger than that commonly found for other chains in solvents of varying thermodynamic quality. Unusually large values of Rv/RH were also recently reported for the related system, polystyreneln-butyl chloride. Such a dependence of RvIRH on solvent quality (larger values in thermodynamically moderate solvents) has not been previously noted or predicted by theory.

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The synthesis, solution properties, and glass transition temperatures of polymethacrylates having alicyclic rings connected to the ester linkage via methylene spacers are reported. The rings cover the range in size from cyclobutyl to cycloundecyl. An attempt was also made to prepare and study poly(cyclopropylmethy1 methacrylate), but free radical solution polymerization led to gels. Solution and thermal properties of these polymers are compared to those previously reported for polymethacrylates with both alicyclyl and n-alkyl substituents. The introduction of themethylene spacer between the ester linkage and the ring results, for small rings, in diminished characteristic ratios relative to those obtained for the alicyclyl materials. Chain flexibilities of poly(alicycly1-methyl methacrylates) are instead found to be identical to those of poly(n-alkyl methacrylates) having the same number of carbons. The glass transition temperatures of the poly(alicyclylmethy1 methacrylates) are generally intermediate to those observed for alicyclyl and n-alkyl methacrylates, but are closer to the former.