Hydrodynamic Properties and Unperturbed Dimensions of Polydecahydro- B -naphthyl and Poly- B -naphthyl Methacrylates in Different Solvents

Intrinsic viscosity, sedimentation, light-scattering, and osmotic-pressure measurements have been carried out at 25 on dilute solutions of polydecahydro-B -naphthyl meth-acrylate (PDNa) and of poly-B-naphthyl methacrylate (PNa). For both polymers, the degree of polydispersity was around 1.5 and the molecular weight range was large: 105 to 3 x 106. Relations between [-n], [S0], A2, and molecular weight have been established. The applicability of the different theories (Stockmayer-Fixman, Kurata-Stockmayer, Fox-Flory, Cowie, Berry, Kamide-Moore) for the determination of the unperturbed dimensions from the viscosity data is discussed; Berry's relation best fits the experimental data. These dimensions, calculated from the sedimentation data according to the Cowie-Bywater relation, agree with those obtained by viscosity. The flexibility factor a is 2.9 for PDNa and 3.1 for PNa. These large values are a consequence of the presence of very bulky groups in the side chain; however, the higher a value for PNa led to the assumption that a specific interaction between the aromatic rings influences the rigidity of the main chain.