From Ring/Linear Blends to Tadpoles: The Role of Connectivity Effects on Polymer Conformations

Blends of linear and ring polymers exhibit remarkable miscibility arising from entropic effects unique to the closed topology of rings. Molecular dynamics simulations have shown that linear chains thread through rings, expanding their conformations and generating a negative effective Flory–Huggins parameter, χ < 0, which enhances mixing and mechanical compatibility¹. Motivated by this entropic mixing behavior, we investigate what occurs when the two architectures are chemically linked to form tadpole polymers—a topology consisting of a ring connected to a linear tail. Using large-scale molecular dynamics simulations, we aim to compare the conformational characteristics and interpenetration behavior of ring and linear segments in both unconnected ring/linear blends and covalently bound tadpoles. The study focuses on how tethering affects the conformational asymmetry, degree of threading, and segmental overlap between components. By contrasting the two systems, we seek to establish how chemical connectivity alters the balance of entropy and topology, providing insights relevant to designing compatibilized polymer blends through topological control.

1. Grest et al. ACS Polym. Au 2023, 3, 209-216.