Shizuo Arichi

Solubility parameters of poly(4-acetoxystyrene) and poly(4-hydroxystyrene)

Abstract The solubility parameters δ2 of poly(4-acetoxystyrene) (PAS) and poly(4-hydroxystyrene) (PHS) were determined by the viscosity measurements and the turbidimetric measurements proposed by Mangaraj et al.1 and Suh and Clarke2, respectively. The δ2 values were compared with those estimated by the calculation methods proposed by Small3, Hoy4 and Fedors5. The δ2 values of PAS and PHS were also determined by the method of Hansen6 in order to obtain additional information on the components of the intermolecular interaction between segments of these polymers. It was found that the δ2 values of PAS and PHS are both considerably larger than those of other linear polymers, but the components of δ2 concerning the dispersion force are almost the same among polystyrene derivatives including PAS and PHS. It was also found that the polar component of δ2 values of PAS and PHS are nearly the same as those of poly(vinylacetate) and poly(methylmethacrylate). Finally, the components of δ2 arising from the hydrogen-bonding formation of PHS are quite large compared with those of other polymers and these may be considered to be the origin of the characteristic properties of this polymer in solid and solution.

Dilute solution properties of poly(4-hydroxystyrene)

Light-scattering and viscosity measurements have been carried out on dilute solutions of poly(4-hydroxystyrene) (PHS) fractions, which were obtained by hydrolysis of poly(4-acetoxystyrene) (PAS). The Mark-Houwink-Sakurada equations were determined in dioxane, tetrahydrofuran, isobutyl acetate and ethyl propionate at 25°C. The unperturbed dimension and the thermodynamic interaction parameters for PHS in various solvents were also determined and compared with those previously obtained for PAS. It was concluded that the hindrance potential of rotation around the C-C bond in the main chain of PHS is influenced more than expected solely from the volume effect of side groups, but it is within the same range found for other polar para-substituted polystyrenes. Also, it was found that in contrast to the PAS-solvent system there are significant energetic and entropic interactions between segments of PHS and solvent molecules, arising from the presence of a hydroxyl group in the side chain.

Unperturbed dimension of poly(4-acetoxystyrene) measured in good and theta solvents

Abstract In order to obtain the additional data concerning the unperturbed dimension of poly-4-substituted styrene, light scattering measurements are performed on the twenty-two fractions with molecular weight of (0.91–352)·104 of poly(4-acetoxystyrene) in dioxan at 25°C, from which the molecular weight obtained was found easily to be evaluated with the gel permeation chromatography using THF. Phase separation experiments for this polymer indicate that the theta state is attained in isopropyl acetate at 19.7°C and butyl acetate at 26.8°C. By making viscosity measurements at that state, the value of KΘ is directly evaluated as 5.4·10−4 dl g−1. The limiting viscosity number is also obtained in good solvents, THF and dioxan, at 25°C and constants of the Mark-Houwink-Sakurada equation in each solvent are determined. Further, approximately the same KΘ as above is obtained from these data with the Stockmayer-Fixman plot. The calculated value of steric factor, 2.37, on this polymer may be plausible, compared with those of polyvinylaromatic derivatives.