Work

Associative polymers with controlled sticker placement: How reversible bond distribution and density govern polymer dynamics

Year: 2026

Type: article

Abstract: Associative polymers with precisely arranged stickers offer opportunities to program material properties with molecular precision. Yet, it remains unclear how the placement and fraction of stickers dictate structure, dynamics, and macroscopic properties. By developing a model unentangled polymer system with hydrogen-bonding stickers, we show that randomly distributed stickers neither form clusters nor change flow properties, whereas stickers placed at chain ends drive nanocluster formation even at low concentrations. Adding more end stickers produces a rubbery plateau spanning eight decades in frequency with two distinct relaxation timescales, in contrast to the single plateau predicted by the classic sticky Rouse model. These results demonstrate that sticker distribution dictates whether associative polymers undergo nanocluster formation or microphase separation, while substantial alterations in dynamics and viscoelasticity require both sticker aggregation and thermomechanical stability of associated domains. Our findings resolve a longstanding debate on associative polymer dynamics and provide molecular design rules for programmable soft materials.

Source: Science Advances

DOI: 10.1126/sciadv.aec4474

Authors: Myoeum Kim, Shalin Patil, Lutz Wiegart, Shiwang Cheng, Li-Heng Cai

Institutions: University of Virginia, Michigan State University, Brookhaven National Laboratory, National Synchrotron Light Source II

Language: English

Topic: Rheology and Fluid Dynamics Studies

Subfield: Fluid Flow and Transfer Processes

Field: Chemical Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $4,500

Funders: National Science Foundation, Virginia Innovation Partnership Corporation, National Institutes of Health