Topology-Dependent Polymer Stretching and Scission in Solution at Extreme Shear Rates

Journal Article · Tue Nov 18 00:00:00 EST 2025 · ACS Polymers Au

DOI:https://doi.org/10.1021/acspolymersau.5c00105· OSTI ID:3017935

van Ravensteijn, Bas G. P. ^[1]; Corona, Patrick T. ^[1]; Datta, Anukta ^[1]; Dai, Kexin ^[1]; Bou Zerdan, Raghida ^[1]; Weigandt, Katie M. ^[2]; Murphy, Ryan P. ^[2]; Hawker, Craig J. ^[1]; Helgeson, Matthew E. ^[1]

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1. Univ. of California, Santa Barbara, CA (United States)
2. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)

There has been significant interest in the engineering of polymer topology to control rheology and mechanical stability in dilute solutions for applications involving extreme shear rate flows. However, methods to experimentally probe properties at relevant shear rates (≈ 10⁴–10⁶ s^–1) have remained ex situ, obscuring access to measures of polymer deformation and rheology that would otherwise provide mechanistic insight into the topology-dependent properties that control their behavior in extreme shear flows. In this study, we used novel in situ small angle neutron scattering measurements in a capillary rheometer (capillary rheo-SANS) to simultaneously measure solution viscosities and polymer deformations in high shear on a series of chemically homologous topology-defined polymers including linear, randomly branched, and star-shaped molecules. We demonstrate that differences in the onset of chain stretching and shear thinning of these polymers in dilute solution are controlled primarily by differences in their molecular relaxation time. These differences correlate with differences in chain scission inferred from ex situ measurements at more extreme shear rates. Together, the results demonstrate a direct coupling between chain deformation and scission, and suggest that the dominant effect of branching as a means to impart resilience against mechanical degradation is through differences in relaxation dynamics due to branching. We anticipate that these results will provide key insights to engineer topology-controlled polymers for rheological modification, mechanical stability, and controlled mechano-chemistry.

• Research Organization: Univ. of California, Santa Barbara, CA (United States); University of California, Santa Barbara, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0020988
• Other Award/Contract Number: 2010792; 2308708; NRT-23
• OSTI ID: 3017935
• Alternate ID(s): OSTI ID: 3025221
• Journal Information: ACS Polymers Au, Journal Name: ACS Polymers Au Journal Issue: 1 Vol. 6; ISSN 2694-2453
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
36 MATERIALS SCIENCE
47 OTHER INSTRUMENTATION
Mechanochemistry
Neutron scattering
Polymer scission
Polymer topology
Solution rheology
mechanochemistry
neutron scattering
polymer scission
polymer topology
solution rheology