Chain length effect on dynamical structure of poly(vinyl pyrrolidone)–polar solvent mixtures in dilute solution of dioxane studied by microwave dielectric relaxation measurement

Pramana

R J Sengwa1¹  Sonu Sankhila¹ 

[1] Microwave Research Laboratory, Department of Physics, J N V University, Jodhpur 342 005, India$$

关键词: Poly(vinyl pyrrolidone);    polar solvents;    binary mixtures;    dielectric relaxation time;    molecular dynamics;    solvent effect.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

Dielectric relaxation study of the binary mixtures of poly(vinyl pyrrolidone) (PVP) (Mw = 24000, 40000 and 360000 g mol-1) with ethyl alcohol (EA) and poly(ethylene glycol)s (PEGs) (Mw = 200 and 400 g mol-1) in dilute solutions of dioxane were carried out at 10.1 GHz and 35°} C. The relaxation time of PVP–EA mixtures was interpreted by the consideration of a wait-and-switch model in the local structure of self-associated ethyl alcohol molecules and also the PVP chain length as a geometric constraint for the reorientational motion of ethyl alcohol molecules. The formation of complexes and effect of PVP chain length on the molecular dynamics, chain flexibility and stretching of PEG molecules in PVP–PEG mixtures were explored from the comparative values of dielectric relaxation time. Further, relaxation time values in dioxane and benzene solvent confirm the viscosity independent molecular dynamics in PVP–EA mixtures but the values vary significantly with the non-polar solvent environment.

【 授权许可】

Unknown