Kazuhiro Kato, K. Araki, A. Abe
Nov 1, 1981
Citations
0
Influential Citations
4
Citations
Journal
Polymer Journal
Abstract
Dielectric measurements were carried out on 1,2-dimethoxy-2-methylpropane (DMMP), a monomer model for poly(oxy-1,1-dimethylethylene) (PODME), in nonpolar solvents such as benzene, carbon tetrachloride, and cyclohexane. The values of the dipole moment ‹μ2›1/2 derived therefrom are 1.69, 1.68, and 1.61 D, respectively, at 25°C. Theoretical calculations performed within the framework of the rotational isomeric state approximations were found to reproduce favorably these experimental results. Conformational energy parameters required in these calculations were estimated by using semiempirical potential energy expressions. The results of the analysis suggest that DMMP differs greatly from dimethoxyethane for which a gauche oxygen effect plays an important role in determining the relative stability of the isomeric states around the skeletal C–C bond. Such an effect is almost entirely suppressed in the former compound: the trans state is preferred to the gauche states by about 0.5 kcal mol1 in the conformational energy. Statistical weight matrices required for the analysis of the PODME chain have also been formulated.