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，
  
  Online First：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

Leibler, L. Theory of microphase separation in block copolymers. Macromolecules 1980 , 13 , 1602−1617..

Akindoyo, J. O.; Beg, M. D. H.; Ghazali, S.; Islam, M. R.; Jeyaratnam, N.; Yuvaraj, A. R. Polyurethane types, synthesis and applications - a review. RSC Adv. 2016 , 6 , 114453−114482..

Golling, F. E.; Pires, R.; Hecking, A.; Weikard, J.; Richter, F.; Danielmeier, K.; Dijkstra, D. Polyurethanes for coatings and adhesives - chemistry and applications. Polym. Int. 2019 , 68 , 848−855..

Paraskar, P. M.; Prabhudesai, M. S.; Hatkar, V. M.; Kulkarni, R. D. Vegetable oil based polyurethane coatings−a sustainable approach: a review. Prog. Org. Coat. 2021 , 156 , 106267..

Wendels, S.; Avérous, L. Biobased polyurethanes for biomedical applications. Bioact. Mater. 2021 , 6 , 1083−1106..

Stribeck, A.; Pöselt, E.; Eling, B.; Jokari-Sheshdeh, F.; Hoelle, A. Thermoplastic polyurethanes with varying hard-seg ment components. Mechanical performance and a filler-crosslink conversion of hard domains as monitored by SAXS. Eur. Polym. J. 2017 , 94 , 340−353..

Abouzahr, S.; Wilkes, G. L.; Ophir, Z. Structure-property behavior of segmented polyether-MDI-butanediol based urethanes: effect of composition ratio. Polymer 1982 , 23 , 1077−1086..

Vanbogart, J. W. C.; Gibson, P. E.; Cooper, S. L. Structure-property relationships in polycaprolactone-polyurethanes. J. Polym. Sci., Polym. Phys. Ed. 1983 , 21 , 65−95..

Nozaki, S.; Masuda, S.; Kamitani, K.; Kojio, K.; Takahara, A.; Kuwarnura, G.; Hasegawa, D.; Moorthi, K.; Mita, K.; Yamasaki, S. Superior properties of polyurethane elastomers synthesized with aliphatic diisocyanate bearing a symmetric structure. Macromolecules 2017 , 50 , 1008−1015..

Shen, Z. H.; Chen, J. L.; Li, G. F.; Situ, G.; Ma, X. F.; Sha, Y.; Zhao, D.; Gu, Q.; Zhang, M.; Luo, Y. L.; Luo, Z. Y. Mechanically robust self-repairing polyurea elastomers: the roles of hard segment content and ordered/disordered hydrogen-bonding arrays. Eur. Polym. J. 2022 , 181 , 111657..

Sami, S.; Yildirim, E.; Yurtsever, M.; Yurtsever, E.; Yilgor, E.; Yilgor, I.; Wilkes, G. L. Understanding the influence of hydrogen bonding and diisocyanate symmetry on the morphology and properties of segmented polyurethanes and polyureas: computational and experimental study. Polymer 2014 , 55 , 4563−4576..

Yildirim, E.; Yurtsever, M. The role of diisocyanate and soft segment on the intersegmental interactions in urethane and urea based segmented copolymers: a DFT study. Comput. Theor. Chem. 2014 , 1035 , 28−38..

Sheth, J. P.; Klinedinst, D. B.; Wilkes, G. L.; Iskender, Y.; Yilgor, I. Role of chain symmetry and hydrogen bonding in segmented copolymers with monodisperse hard segments. Polymer 2005 , 46 , 7317−7322..

D'Arlas, B. F.; Rueda, L.; De la Caba, K.; Mondragon, I.; Eceiza, A. Microdomain composition and properties differences of biodegradable polyurethanes based on MDI and HDI. Polym. Eng. Sci. 2008 , 48 , 519−529..

Asensio, M.; Ferrer, J. F.; Nohales, A.; Culebras, M.; Gomez, C. M. The role of diisocyanate structure to modify properties of segmented polyurethanes. Materials 2023 , 16 , 1633..

Lee, D. K.; Tsai, H. B. Properties of segmented polyurethanes derived from different diisocyanates. J. Appl. Polym. Sci. 2000 , 75 , 167−174..

Wang, H. R.; Cao, L.; Wang, X. L.; Lang, X. R.; Cong, W. W.; Han, L.; Zhang, H. Y.; Zhou, H. B.; Sun, J. J.; Zong, C. Z. Effects of isocyanate structure on the properties of polyurethane: synthesis, performance, and self-healing characteristics. Polymers 2024 , 16 , 3045..

Hojabri, L.; Kong, X. H.; Narine, S. S. Novel long chain unsaturated diisocyanate from fatty acid: synthesis, characterization, and application in bio-based polyurethane. J. Polym. Sci., Part A: Polym. Chem. 2010 , 48 , 3302−3310..

Niesiobędzka, J.; Datta, J. Challenges and recent advances in bio-based isocyanate production. Green Chem. 2023 , 25 , 2482−2504..

Vargas, J. A. M.; Mandrekar, K. S.; Echemendía, R.; Burtoloso, A. C. B. Innovations in isocyanate synthesis for a sustainable future. Org. Biomol. Chem. 2025 , 23 , 487 −505..

Prisacariu, C.; Scortanu, E.; Stoica, I.; Agapie, B.; Barboiu, V. Morphological features and thermal and mechanical response in segmented polyurethane elastomers based on mixtures of isocyanates. Polym. J. 2011 , 43 , 613−620..

Lee, S. Y.; Lee, J. S.; Kim, B. K. Preparation and properties of water-borne polyurethanes. Polym. Int. 1997 , 42 , 67−76..

Prisacariu, C.; Olley, R. H.; Caraculacu, A. A.; Bassett, D. C.; Martin, C. The effect of hard segment ordering in copolyurethane elastomers obtained by using simultaneously two types of diisocyanates. Polymer 2003 , 44 , 5407−5421..

Xu, W.; Zhang, R. Y.; Liu, W.; Zhu, J.; Dong, X.; Guo, H. X.; Hu, G. H. A multiscale investigation on the mechanism of shape recovery for IPDI to PPDI hard segment substitution in polyurethane. Macromolecules 2016 , 49 , 5931−5944..

Huang, S. L.; Lai, J. Y. Structure-tensile properties of polyurethanes. Eur. Polym. J. 1997 , 33 , 1563−1567..

Ahmad, M.; Luo, J. K.; Xu, B.; Purnawali, H.; King, P. J.; Chalker, P. R.; Fu, Y. Q.; Huang, W. M.; Miraftab, M. Synthesis and characterization of polyurethane-based shape-memory polymers for tailored T g around body temperature for medical applications. Macromol. Chem. Phys. 2011 , 212 , 592−602..

Oh, J.; Kim, Y. K.; Hwang, S. H.; Kim, H. C.; Jung, J. H.; Jeon, C. H.; Lim, S. K. Synthesis and characterization of improved bio-based carbon content thermoplastic polyurethane with bio-aliphatic and petro-aromatic diisocyanate. J. Appl. Polym. Sci. 2023 , 140 , e54088..

Yang, C. H.; Yang, H. J.; Wen, T. C.; Wu, M. S.; Chang, J. S. Mixture design approaches to IPDI-H 6 XDI-XDI ternary diisocyanate-based waterborne polyurethanes. Polymer 1999 , 40 , 871−885..

Rahman, M. M.; Hasneen, A.; Jo, N. J.; Kim, H. I.; Lee, W. K. Properties of waterborne polyurethane adhesives with aliphatic and aromatic diisocyanates. J. Adhes. Sci. Technol. 2011 , 25 , 2051−2062..

Palaniandy, K.; Auckloo, S. A. B.; Cavallaro, G.; Lazzara, G.; Chan, E. S.; Pasbakhsh, P. Hybrid aliphati c and aromatic diisocyanates forming mixed urea segments for high-performance polyurea. Prog. Org. Coat. 2024 , 189 , 108315..

Rahman, M. M.; Lee, I.; Chun, H. H.; Kim, H. D.; Park, H. Properties of waterborne polyurethane-fluorinated marine coatings: the effect of different types of diisocyanates and tetrafluorobutanediol chain extender content. J. Appl. Polym. Sci. 2014 , 131 , 39905..

Bailey, M. E.; Kirss, V.; Spaunburgh, R. G. Reactivity of organic isocyanates. Ind. Eng. Chem. 1956 , 48 , 794−797..

VandeVondele, J.; Krack, M.; Mohamed, F.; Parrinello, M.; Chassaing, T.; Hutter, J. QUICKSTEP: Fast and accurate density functional calculations using a mixed Gaussian and plane waves approach. Comput. Phys. Commun. 2005 , 167 , 103−128..

Goedecker, S.; Teter, M.; Hutter, J. Separable dual-space Gaussian pseudopotentials. Phys. Rev. B 1996 , 54 , 1703−1710..

Hartwigsen, C.; Goedecker, S.; Hutter, J. Relativistic separable dual-space Gaussian pseudopotentials from H to Rn. Phys. Rev. B 1998 , 58 , 3641−3662..

[VandeVondele, J.; Hutter, J. Gaussian basis sets for accurate calculations on molecular systems in gas and condensed phases. J. Chem. Phys . 2007 , 127 ..

Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996 , 77 , 3865−3868..

Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys. 2010 , 132 , 154104..

Zhang, C. L.; Hu, J. L.; Li, X.; Wu, Y.; Han, J. P. Hydrogen-bonding interactions in hard segments of shape memory polyurethane: toluene diisocyanates and 1,6-hexamethylene diisocyanate. A theoretical and comparative study. J. Phys. Chem. A 2014 , 118 , 12241−12255..

Lempesis, N.; in ‘t Veld, P. J.; Rutledge, G. C. Simulation of the structure and mechanics of crystalline 4,4′-diphenylmethane diisocyanate (MDI) with n-butanediol (BDO) as chain extender. Polymer 2016 , 107 , 233−239..

Sherrill, C. D.; Takatani, T.; Hohenstein, E. G. An assessment of theoretical methods for nonbonded interactions: comparison to complete basis set limit coupled-cluster potential energy curves for the benzene dimer, the methane dimer, benzene-methane, and benzene-H 2 S. J. Phys. Chem. A 2009 , 113 , 10146−10159..

[Janiak, C. A critical account on π–π stacking in metal complexes with aromatic nitrogen-containing ligands. J. Chem. Soc., Dalton Trans . 2000 , 3885-3896..

Steiner, T. The hydrogen bond in the solid state. Angew. Chem. Int. Ed. 2002 , 41 , 48−76..

Herschlag, D.; Pinney, M. M. Hydrogen bonds: simple after all. Biochemistry 2018 , 57 , 3338−3352..

Coleman, M. M.; Lee, K. H.; Skrovanek, D. J.; Painter, P. C. Hydrogen-bonding in polymers. 4. Infrared temperature studies of a simple polyurethane. Macromolecules 1986 , 19 , 21 49−2157..

Teo, L. S.; Chen, C. Y.; Kuo, J. F. Fourier transform infrared spectroscopy study on effects of temperature on hydrogen bonding in amine-containing polyurethanes and poly(urethane-urea)s. Macromolecules 1997 , 30 , 1793−1799..

Wang, Z. Y.; Liu, Z. R.; Gao, Z. D.; Li, X. K.; Eling, B.; Poeselt, E.; Schander, E.; Wang, Z. B. Structure transition of aliphatic m,6-polyurethane during heating investigated using in-situ WAXS, SAXS, and FTIR. Polymer 2022 , 254 , 125072..

Hood, M. A.; Wang, B. B.; Sands, J. M.; La Scala, J. J.; Beyer, F. L.; Li, C. Y. Morphology control of segmented polyurethanes by crystallization of hard and soft segments. Polymer 2010 , 51 , 2191−2198..

Fernández, C. E.; Bermudez, M.; Versteegen, R. M.; Meijer, E. W.; Muller, A. J.; Muñoz-Guerra, S. Crystallization studies on linear aliphatic n-polyurethanes. J. Polym. Sci., Part B: Polym. Phys. 2009 , 47 , 1368−1380..

Balko, J.; Fernández-d'Arlas, B.; Pöselt, E.; Dabbous, R.; Müller, A. J.; Thurn-Albrecht, T. Clarifying the origin of multiple mel ting of segmented thermoplastic polyurethanes by fast scanning calorimetry. Macromolecules 2017 , 50 , 7672−7680..

McKiernan, R. L.; Heintz, A. M.; Hsu, S. L.; Atkins, E. D. T.; Penelle, J.; Gido, S. P. Influence of hydrogen bonding on the crystallization behavior of semicrystalline polyurethanes. Macromolecules 2002 , 35 , 6970−6974..

Ryan, A. J.; Bras, W.; Mant, G. R.; Derbyshire, G. E. A direct method to determine the degree of crystallinity and lamellar thickness of polymers: application to polyethylene. Polymer 1994 , 35 , 4537−4544..

[Stribeck, N. X-ray scattering of soft matter . Springer: Berlin, Heidelberg, 2007 , p. 95-190..

Saito, Y.; Nansai, S.; Kinoshit. S Structural studies on polyurethane fibers. I. Crystal and molecular structures of aliphatic polyurethanes from hexamethylene diisocyanate and some linear glycols. Polym. J. 1972 , 3 , 113−121..

Fernández, C. E.; Bermúdez, M.; Muñoz-Guerra, S.; León, S.; Versteegen, R. M.; Meijer, E. W . Crystal structure and morphology of linear aliphatic n-polyurethanes. Macromolecules 2010 , 43 , 4161−4171..

Vonk, C. G. Investigation of non-ideal two-phase polymer structures by small-angle X-ray scattering. J. Appl. Crystallogr. 1973 , 6 , 81−86..

Goderis, B.; Reynaers, H.; Koch, M. H. J.; Mathot, V. B. F. Use of SAXS and linear correlation functions for the determination of the crystallinity and morphology of semi-crystalline polymers. Application to linear polyethylene. J. Polym. Sci., Part B: Polym. Phys. 1999 , 37 , 1715−1738..

Yeh, F.; Hsiao, B. S.; Sauer, B. B.; Michel, S.; Siesler, H. W. In-situ studies of structure development during deformation of a segmented poly(urethane-urea) elastomer. Macromolecules 2003 , 36 , 1940−1954..

Fernández-d'Arlas, B.; Baumann, R. P.; Pöselt, E.; Müller, A. J. Influence of composition on the isothermal crystallisation of segmented thermoplastic polyurethanes. CrystEngComm 2017 , 19 , 4720−4733..

Ziegler, W.; Guttmann, P.; Kopeinig, S .; Dietrich, M.; Amirosanloo, S.; Riess, G.; Kern, W. Influence of different polyol segments on the crystallisation behavior of polyurethane elastomers measured with DSC and DMA experiments. Polym. Test. 2018 , 71 , 18−26..

Klinedinst, D. B.; Yilgör, I.; Yilgör, E.; Zhang, M. Q.; Wilkes, G. L. The effect of varying soft and hard segment length on the structure-property relationships of segmented polyurethanes based on a linear symmetric diisocyanate, 1,4-butanediol and PTMO soft segments. Polymer 2012 , 53 , 5358−5366..

Li, Y. J.; Ren, Z. Y.; Zhao, M.; Yang, H. C.; Chu, B. Multiphase structure of segmented polyurethanes: effects of hard-segment flexibility. Macromolecules 1993 , 26 , 612−622..

Waletzko, R. S.; Korley, L. T. J.; Pate, B. D.; Thomas, E. L.; Hammond, P. T. Role of increased crystallinity in deformation-induced structure of segmented thermoplastic polyurethane elastomers with PEO and PEO-PPO-PEO soft segments and HDI hard segments. Macromolecules 2009 , 42 , 2041−2053..

Solouki Bonab, V.; Manas-Zloczower, I. Revisiting thermoplastic polyurethane, from composition to morphology and properties. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 1553−1564..

Li, X. K.; Lu, Y.; Wang, H.; Pöselt, E.; Eling, B.; Men, Y. F. Crystallization of hard segments in MDI/BD-based polyurethanes deformed at elevated temperature and their dependence on the MDI/BD content. Eur. Polym. J. 2017 , 97 , 423−436..

[Ferry, J. D. Viscoelastic properties of polymers . John Wiley and Son: New York, 1980 Vol. 264, p. 270-285..

Hong, K.; Rastogi, A.; Strobl, G. A model treating tensile deformation of semicrystalline polymers: quasi-static stress-strain relationship and viscous stress determined for a sample of polyethylene. Macromolecules 2004 , 37 , 10165−10173..

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