A Strategy to Tailor Mechanical Properties of Thermoplastic Polyurethane through Altering the Terminal Diisocyanate Structure of Hard Segment

Ze-Hao Wang; Chen-Ding Wang; Xiao-Li Zhao; Xiao-Niu Yang

doi:10.1007/s10118-025-3455-y

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A Strategy to Tailor Mechanical Properties of Thermoplastic Polyurethane through Altering the Terminal Diisocyanate Structure of Hard Segment

RESEARCH ARTICLE | Updated：2025-12-03

- A Strategy to Tailor Mechanical Properties of Thermoplastic Polyurethane through Altering the Terminal Diisocyanate Structure of Hard Segment
- Chinese Journal of Polymer Science Vol. 43, Issue 12, Pages: 2335-2348(2025)
- Affiliations：
  
  a.State Key Laboratory of Polymer Physics and Chemistry & Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
  b.School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
  c.Key Laboratory of High-Performance Synthetic Rubber and its Composite Materials & Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- Author bio：
  
  zhaoxiaoli@ciac.ac.cn (X.L.Z.)
  xnyang@ciac.ac.cn (X.N.Y.)
- Funds：
- DOI：10.1007/s10118-025-3455-y
  CLC：
- Received：27 August 2025，
  
  Accepted：18 September 2025，
  
  Published Online：19 November 2025，
  
  Published：15 December 2025
- Accepted：
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Wang, Z. H.; Wang, C. D.; Zhao, X. L.; Yang, X. N. A strategy to tailor mechanical properties of thermoplastic polyurethane through altering the terminal diisocyanate structure of hard segment. Chinese J. Polym. Sci. 2025, 43, 2335–2348

Ze-Hao Wang, Chen-Ding Wang, Xiao-Li Zhao, et al. A Strategy to Tailor Mechanical Properties of Thermoplastic Polyurethane through Altering the Terminal Diisocyanate Structure of Hard Segment[J]. Chinese Journal of Polymer Science, 2025, 43(12): 2335-2348.
Wang, Z. H.; Wang, C. D.; Zhao, X. L.; Yang, X. N. A strategy to tailor mechanical properties of thermoplastic polyurethane through altering the terminal diisocyanate structure of hard segment. Chinese J. Polym. Sci. 2025, 43, 2335–2348 DOI： 10.1007/s10118-025-3455-y.

Ze-Hao Wang, Chen-Ding Wang, Xiao-Li Zhao, et al. A Strategy to Tailor Mechanical Properties of Thermoplastic Polyurethane through Altering the Terminal Diisocyanate Structure of Hard Segment[J]. Chinese Journal of Polymer Science, 2025, 43(12): 2335-2348. DOI： 10.1007/s10118-025-3455-y.

摘要

This work demonstrates a molecular design strategy for tuning TPU’s modulus by altering the terminal diisocyanate in hard segments. Combining DFT and microstructural analysis

it reveals how the diisocyanate geometry and competition between π–π stacking and hydrogen bond govern hydrogen bond formation

crystallization

and physical crosslinking network.

Abstract

Adjusting the structure of the hard segment (HS) represents a key method for manipulating the mechanical properties of thermoplastic polyurethane (TPU). This study developed a novel molecular design strategy to tailor TPU’s mechani

cal performance through altering the terminal diisocyanate structure of HS. The typical HDI-BDO based TPU was chosen as a model. Replacing HS’s terminal HDI residues with aromatic PPDI

TODI

and MDI (the corresponding TPUs are named as 2P

2TO

and 2M

respectively) enabled broad tuning of TPU’s Young's modulus while maintaining high tensile strength and elongation. Compared with linear PPDI and TODI

the bent and unsymmetrical MDI exhibits greater deviation from the central axis of the middle HDI-BDO segment

which reduces HS’s capability of three-dimensionally ordered packing. Therefore

2P and 2TO show higher hydrogen bond content and crystallinity

stronger physical crosslinking network

and thus much higher Young's modulus than 2M (75.6 MPa). Besides geometric structure

–

stacking between HS’s terminal aromatic diisocyanates critically governs TPU’s physical crosslinking network. In 2P

–

stacking induces torsion of the middle HDI-BDO segment and disrupts the neighboring hydrogen bonds

leading to a dense network with fine hard blocks. In contrast

the lateral methyl groups in TODI hinder

–

stacking

resulting in a sparse network with large hard blocks. Accordingly

2TO exhibits a higher Young's modulus (146.2 MPa) than 2P (124.0 MPa)

but greater strain-rate sensitivity.

关键词

Keywords

references

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