Dielectric Normal Mode Process in Solutions of cis-PolyisopreneKeiichiro, ADACHI

摘要

The “dielectric normal mode process”, dielectric relaxation due to fluctuation of the end-to-end vector of flexible polymer chains, was investigated for solutions of cis-polyisoprene in two good solvents, benzene and toluene, and in a θ solvent, dioxane. The width of the distribution of the relaxation time increased with increasing concentration C. This behavior was explained based on the tube model by considering three kinds of motions of the chain: (i) orientation of the parts of the chain ends having a size of molecular weight between entanglements Me, (ii) stretching of the chain in a tube, and (iii) chain disengagement from tube or reptation motion. The relaxation time τn for the normal mode process also increased with increasing C. In the semidilute range of 0.02