Bead-Spring Model Analysis of Linear Viscoelasticity for Unentangled Multi-Cyclic Polystyrene Melts
Year: 2026
Type: preprint
Abstract: Multi-cyclic (MC) polymers, in which multiple ring units are connected within a single molecule, are expected to exhibit properties distinct from those of linear and trivial ring polymers. Here, we performed graph-theory-based bead-spring model calculations for a series of unentangled MC polystyrene (MC-PS) melts with different chain connectivities and compared the results with previously reported experimental linear viscoelastic data. This calculation allows for the comparison of linear viscoelasticity among different MC molecules using a single, architecture-independent time-scale. The distribution and multiplicity of the eigenvalues λ p at mode number p , which determine the relaxation times through τ p ∝ 1/ λ p , of the MC molecules depends strongly on the architecture and its overall symmetry. In addition, the model reasonably captured the experimental linear rheological behavior of the MC-PS melts, including the complex modulus G * ( ω ) and the zero-shear viscosity η 0 , although the experimental data have modest differences. Furthermore, we found that the architecture dependence of η 0 can be semi-quantitatively organized using the squared radius of gyration calculated from the bead-spring model, R g,BS 2 , rather than relying only on the number of constrained segments, n cs , which has been used as an empirical architectural parameter in previous studies. This descriptor also distinguishes MC architectures with the same n cs but different rheological responses, demonstrating that chain connectivity provides a physically grounded basis for describing the linear viscoelasticity of unentangled MC polymer melts.
Source: ChemRxiv
Authors: Yuya Doi, Takeshi Sato, Zhi-Chao Yan
Language: English
Subfield: Fluid Flow and Transfer Processes
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223314088