Molecular Weight Distribution Effects on the Structural and Mechanical Performance of Conjugated Polymers Incorporating Flexible Spacers: A Simulation Study

Hai-Yan Weng; Ji-Yuan Xing; Rui Shi; Zhong-Yuan Lu

doi:10.1007/s10118-026-3626-5

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Molecular Weight Distribution Effects on the Structural and Mechanical Performance of Conjugated Polymers Incorporating Flexible Spacers: A Simulation Study

RESEARCH ARTICLE | Updated：2026-07-01

- Molecular Weight Distribution Effects on the Structural and Mechanical Performance of Conjugated Polymers Incorporating Flexible Spacers: A Simulation Study
  Enhanced Publication
- Chinese Journal of Polymer Science Vol. 44, Issue 7, Pages: 2331-2340(2026)
- Affiliations：
  
  a.State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
  b.State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130023, China
- Author bio：
  
  shirui816@jlu.edu.cn (R.S.)
  luzhy@jlu.edu.cn (Z.Y.L.)
- Funds：
- DOI：10.1007/s10118-026-3626-5
  CLC：
- Received：15 February 2026，
  
  Accepted：12 March 2026，
  
  Online First：28 May 2026，
  
  Published：05 July 2026
- Accepted：
Scan QR Code
Weng, H. Y.; Xing, J. Y.; Shi, R.; Lu, Z. Y. Molecular weight distribution effects on the structural and mechanical performance of conjugated polymers incorporating flexible spacers: a simulation study. Chinese J. Polym. Sci. 2026, 44, 2331–2340

Hai-Yan Weng, Ji-Yuan Xing, Rui Shi, et al. Molecular Weight Distribution Effects on the Structural and Mechanical Performance of Conjugated Polymers Incorporating Flexible Spacers: A Simulation Study[J]. Chinese Journal of Polymer Science, 2026, 44(7): 2331-2340.
Weng, H. Y.; Xing, J. Y.; Shi, R.; Lu, Z. Y. Molecular weight distribution effects on the structural and mechanical performance of conjugated polymers incorporating flexible spacers: a simulation study. Chinese J. Polym. Sci. 2026, 44, 2331–2340 DOI： 10.1007/s10118-026-3626-5.

Hai-Yan Weng, Ji-Yuan Xing, Rui Shi, et al. Molecular Weight Distribution Effects on the Structural and Mechanical Performance of Conjugated Polymers Incorporating Flexible Spacers: A Simulation Study[J]. Chinese Journal of Polymer Science, 2026, 44(7): 2331-2340. DOI： 10.1007/s10118-026-3626-5.

摘要

This work demonstrates that molecular weight distribution

quantified by the polydispersity index (PDI)

governs structure-property relationships in conjugated polymers incorporating flexible spacers. Increasing PDI promotes a loop-to-bridge conformational transition

transforming lamellar phase to perforated lamellar phase at intermediate rigid-segment lengths

switching deformation from destructive fibrillation to reconstructive strengthening

and enhancing both yield strength and strain.

Abstract

Conjugated polymers incorporating flexible spacers (CP-FSs) offer a promising route to mechanically robust active layers for flexible organic solar cells. However

the influence of molecular weight distribution (MWD)—a fundamental polymer characteristic—on structural and mechanical performance remains poorly understood due to synthetic challenges. Here

we employ dissipative particle dynamics and coarse-grained molecular dynamics simulations to elucidate how MWD

quantified by polydispersity index (PDI)

governs structure-property relationships in CP-FSs. Our results reveal that PDI acts as a molecular switch controlling phase morphology: increasing PDI drives transitions from lamellar to perforated lamellar structures at intermediate rigid segment lengths. At the molecular level

higher PDI significantly increases the fraction of bridging conformations (

$$ {\nu }_{\mathrm{bridge}} $$

https://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=111930340&type=

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)

strengthening a load-bearing network. During tensile deformation

this enhanced load-bearing network suppresses destructive fibrillation and instead promotes reconstructive strengthening through dynamic loop-to-bridge transitions. These findings demonstrate that controlled MWD offers a composition-independent strategy for developing mechanically robust active layers

providing practical guidelines for flexible organic solar cell design.

关键词

Keywords

references

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