Contribution of Polymer-Solvent Interactions to Dynamics of Linear Polymers in Dilute Solutions

Abstract

In this work a theoretical approach to dynamics of linear vinyl polymers in dilute solutions of high viscosity solvents is presented. The calculations for the relaxation time spectra, polymer intrinsic viscosity [η (ω)], complex elastic modulus G*(ω), total intrinsic viscosity [ηT (ω)] and specific heat capacity C (ω) were carried out in the non-free-draining limits. The relaxation time spectrum calculated for dynamics of low frequency modes exhibits a Rouse-like character. Its position and shape corresponds to the ultrasonic relaxation time spectrum observed in the system at 106 Hz. On the other hand, the relaxation time spectrum associated with moderate frequency mode dynamics is narrower and typical for ultrasonic relaxation observed at 107 Hz. The polymer intrinsic viscosity [η (ω)] and elastic modulus G*(ω) are shown to be represented by the model within a low-frequency range. In turn, the specific heat capacity C (ω) is displayed as a representation of the model in the acoustic region mentioned above. In the high-frequency range the dynamics is described by the total intrinsic viscosity [ηT (ω)] tending to a plateau where the value is equal to the sum of the single-bead intrinsic viscosity [ηN] and effective solvent viscosity [ηeff].