Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Natural rubber with high resistance to crack growth

Nature Sustainability volume 8, pages 692–701 (2025)Cite this article

Subjects

Abstract

Natural rubber, with annual production of 15 million tonnes, is the most used bio-elastomer. Improving its resistance to crack growth is highly desired, to prolong its service life for many applications and eventually improve its sustainability. Here we markedly amplify the resistance to crack growth in natural rubber by forming a tanglemer, a polymer network in which entanglements greatly outnumber crosslinks. Specifically, we cast natural rubber latex without high-intensity processing that cuts long polymers. The long polymers densely entangle by thermal motion and are then sparsely crosslinked. At a crack tip, long polymer strands between neighbouring crosslinks deconcentrate stress, extend strain-induced crystallization over a large region and enhance crystallinity. For example, when the ratio of crosslinks to repeat units reduces from 10−2 to 10−3, the network amplifies fatigue threshold from ~50 J m−2 to ~200 J m−2, and toughness from ~104 J m−2 to over 105 J m−2. Overall, this work provides a viable strategy to improve the practical applicability of natural rubber, contributing to the development of sustainable polymers.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to the full article PDF.

USD 39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Natural rubber tanglemer outperforms regular natural rubber.
Fig. 2: Process a latex into a tanglemer.
Fig. 3: Uniaxial tensile behaviour.
Fig. 4: Crack growth under cyclic stretch.
Fig. 5: Crack growth under monotonic stretch.
Fig. 6: Natural rubber tanglemer is crack-resistant in extreme conditions.

Similar content being viewed by others

Data availability

All data presented in the Supplementary Information figures are available as Source Data. Source data are provided with this paper.

References

  1. Watari, T., Hata, S., Nakajima, K. & Nansai, K. Limited quantity and quality of steel supply in a zero-emission future. Nat. Sustain. 6, 336–343 (2023).

    Article  Google Scholar 

  2. Del Rio, D. D. F. et al. Decarbonizing the glass industry: a critical and systematic review of developments, sociotechnical systems and policy options. Renew. Sustain. Energy Rev. 155, 111885 (2022).

    Article  Google Scholar 

  3. Wu, W. et al. Reprocessable and ultratough epoxy thermosetting plastic. Nat. Sustain. 7, 804–811 (2024).

    Article  Google Scholar 

  4. Assi, L. et al. Sustainable concrete: building a greener future. J. Clean. Prod. 198, 1641–1651 (2018).

    Article  CAS  Google Scholar 

  5. Tanaka, Y. & Tarachiwin, L. Recent advances in structural characterization of natural rubber. Rubber Chem. Technol. 82, 283–314 (2009).

    Article  CAS  Google Scholar 

  6. White, J. L. in Science and Technology of Rubber 2nd edn (eds Mark, J. E. et al.) 257–338 (Elsevier, 1994).

  7. Lake, G. J. & Thomas, A. G. The strength of highly elastic materials. Proc. R. Soc. A 300, 108–119 (1967).

    CAS  Google Scholar 

  8. Rivlin, R. S. & Thomas, A. G. Rupture of rubber. I. Characteristic energy for tearing. J. Polym. Sci. 10, 291–318 (1953).

    Article  CAS  Google Scholar 

  9. de Gennes, P. G. Reptation of a polymer chain in the presence of fixed obstacles. J. Chem. Phys. 55, 572–579 (1971).

    Article  Google Scholar 

  10. Patel, S. K., Malone, S., Cohen, C., Gillmor, J. R. & Colby, R. H. Elastic modulus and equilibrium swelling of poly(dimethylsiloxane) networks. Macromolecules 25, 5241–5251 (1992).

    Article  CAS  Google Scholar 

  11. Rubinstein, M. & Panyukov, S. Elasticity of polymer networks. Macromolecules 35, 6670–6686 (2002).

    Article  CAS  Google Scholar 

  12. Kim, J., Zhang, G., Shi, M. & Suo, Z. Fracture, fatigue, and friction of polymers in which entanglements greatly outnumber cross-links. Science 374, 212–216 (2021).

    Article  CAS  Google Scholar 

  13. Nian, G., Kim, J., Bao, X. & Suo, Z. Making highly elastic and tough hydrogels from doughs. Adv. Mater. 34, 2206577 (2022).

    Article  CAS  Google Scholar 

  14. Bao, X. et al. Low-intensity mixing process of high molecular weight polymer chains leads to elastomers of long network strands and high fatigue threshold. Soft Matter 19, 5956–5966 (2023).

    Article  CAS  Google Scholar 

  15. Steck, J., Kim, J., Kutsovsky, Y. & Suo, Z. Multiscale stress deconcentration amplifies fatigue resistance of rubber. Nature 624, 303–308 (2023).

    Article  CAS  Google Scholar 

  16. Chen, Z., Zhang, G., Luo, Y. & Suo, Z. Rubber-glass nanocomposites fabricated using mixed emulsions. Proc. Natl Acad. Sci. USA 121, e2322684121 (2024).

    Article  CAS  Google Scholar 

  17. Westall, B. The molecular weight distribution of natural rubber latex. Polymer 9, 243–248 (1968).

    Article  CAS  Google Scholar 

  18. Fuller, K. N. G. & Fulton, W. S. The influence of molecular weight distribution and branching on the relaxation behaviour of uncrosslinked natural rubber. Polymer 31, 609–615 (1990).

    Article  CAS  Google Scholar 

  19. Tangpakdee, J. & Tanaka, Y. Characterization of sol and gel in Hevea natural rubber. Rubber Chem. Technol. 70, 707–713 (1997).

    Article  CAS  Google Scholar 

  20. Fetters, L. J., Lohse, D. J., Richter, D., Witten, T. A. & Zirkel, A. Connection between polymer molecular weight, density, chain dimensions, and melt viscoelastic properties. Macromolecules 27, 4639–4647 (1994).

    Article  CAS  Google Scholar 

  21. Harmon, D. J. & Jacobs, H. L. Degradation of natural rubber during mill mastication. J. Appl. Polym. Sci. 10, 253–257 (1966).

    Article  CAS  Google Scholar 

  22. Winnik, M. A. Latex film formation. Curr. Opin. Colloid Interface Sci. 2, 192–199 (1997).

    Article  CAS  Google Scholar 

  23. Wei, Y.-C., Xia, J.-H., Zhang, L., Zheng, T.-T. & Liao, S. Influence of non-rubber components on film formation behavior of natural rubber latex. Colloid Polym. Sci. 298, 1263–1271 (2020).

    Article  CAS  Google Scholar 

  24. Amnuaypornsri, S., Sakdapipanich, J. & Tanaka, Y. Green strength of natural rubber: the origin of the stress–strain behavior of natural rubber. J. Appl. Polym. Sci. 111, 2127–2133 (2009).

    Article  CAS  Google Scholar 

  25. Thomas, D. K. Crosslinking efficiency of dicumyl peroxide in natural rubber. J. Appl. Polym. Sci. 6, 613–616 (1962).

    Article  CAS  Google Scholar 

  26. Flory, P. J. Principles of Polymer Chemistry (Cornell Univ. Press, 1953).

  27. Rubinstein, M. & Colby, R. H. Polymer Physics (Oxford Univ. Press, 2003).

  28. Trabelsi, S., Albouy, P.-A. & Rault, J. Crystallization and melting processes in vulcanized stretched natural rubber. Macromolecules 36, 7624–7639 (2003).

    Article  CAS  Google Scholar 

  29. Plazek, D. J. Effect of crosslink density on the creep behavior of natural rubber vulcanizates. J. Polym. Sci. A2 Polym. Phys. 4, 745–763 (1966).

    Article  CAS  Google Scholar 

  30. Farlie, E. D. Creep and stress relaxation of natural rubber vulcanizates. Part I. Effect of crosslink density on the rate of creep in different vulcanizing systems. J. Appl. Polym. Sci. 14, 1127–1141 (1970).

    Article  CAS  Google Scholar 

  31. Flory, P. J. Thermodynamics of crystallization in high polymers. I. Crystallization induced by stretching. J. Chem. Phys. 15, 397–408 (1947).

    Article  CAS  Google Scholar 

  32. Hartquist, C. M. et al. An elastomer with ultrahigh strain-induced crystallization. Sci. Adv. 9, eadj0411 (2023).

    Article  CAS  Google Scholar 

  33. Chenal, J.-M., Chazeau, L., Guy, L., Bomal, Y. & Gauthier, C. Molecular weight between physical entanglements in natural rubber: a critical parameter during strain-induced crystallization. Polymer 48, 1042–1046 (2007).

    Article  CAS  Google Scholar 

  34. Huneau, B. Strain-induced crystallization of natural rubber: a review of X-ray diffraction investigations. Rubber Chem. Technol. 84, 425–452 (2011).

    Article  CAS  Google Scholar 

  35. Mars, W. & Fatemi, A. A literature survey on fatigue analysis approaches for rubber. Int. J. Fatigue 24, 949–961 (2002).

    Article  CAS  Google Scholar 

  36. Bhowmick, A. K. Threshold fracture of elastomers. J. Macromol. Sci. C 28, 339–370 (1988).

    Article  Google Scholar 

  37. Zhou, Y. et al. The stiffness-threshold conflict in polymer networks and a resolution. J. Appl. Mech. 87, 031002 (2020).

    Article  CAS  Google Scholar 

  38. Rublon, P. et al. In situ synchrotron wide-angle X-ray diffraction investigation of fatigue cracks in natural rubber. J. Synchrotron Radiat. 20, 105–109 (2013).

    Article  CAS  Google Scholar 

  39. Demassieux, Q., Berghezan, D. & Creton, C. in Fatigue Crack Growth in Rubber Materials, Vol. 286 (eds Heinrich, G. et al.) 467–491 (Springer International Publishing, 2020).

  40. Lake, G. J. & Lindley, P. B. Cut growth and fatigue of rubbers. II. Experiments on a noncrystallizing rubber. J. Appl. Polym. Sci. 8, 707–721 (1964).

    Article  CAS  Google Scholar 

  41. Thomas, A. G. Rupture of rubber. V. Cut growth in natural rubber vulcanizates. J. Polym. Sci. 31, 467–480 (1958).

    Article  Google Scholar 

  42. Suo, Z., Bao, G. & Fan, B. Delamination R-curve phenomena due to damage. J. Mech. Phys. Solids 40, 1–16 (1992).

    Article  Google Scholar 

  43. Launey, M. E. & Ritchie, R. O. On the fracture toughness of advanced materials. Adv. Mater. 21, 2103–2110 (2009).

    Article  CAS  Google Scholar 

  44. Mars, W. V. & Fatemi, A. Factors that affect the fatigue life of rubber: a literature survey. Rubber Chem. Technol. 77, 391–412 (2004).

    Article  CAS  Google Scholar 

  45. Saintier, N., Cailletaud, G. & Piques, R. Cyclic loadings and crystallization of natural rubber: an explanation of fatigue crack propagation reinforcement under a positive loading ratio. Mater. Sci. Eng. A 528, 1078–1086 (2011).

    Article  Google Scholar 

  46. Lindley, P. B. Relation between hysteresis and the dynamic crack growth resistance of natural rubber. Int. J. Fract. 9, 449–462 (1973).

    Article  CAS  Google Scholar 

  47. Ikeda, Y., Yasuda, Y., Hijikata, K., Tosaka, M. & Kohjiya, S. Comparative study on strain-induced crystallization behavior of peroxide cross-linked and sulfur cross-linked natural rubber. Macromolecules 41, 5876–5884 (2008).

    Article  CAS  Google Scholar 

  48. Kruželák, J., Sýkora, R. & Hudec, I. Peroxide vulcanization of natural rubber. Part I: effect of temperature and peroxide concentration. J. Polym. Eng. 34, 617–624 (2014).

    Article  Google Scholar 

  49. Parks, C. R. Retardation of scorch in rubber compounds containing dicumyl peroxide as the vulcanizing agent. US Patent 3,384,613 (1968).

  50. González Hernández, L., Rodríguez-Díaz, A., Valentín, J. L., Marcos-Fernández, Á. & Posadas, P. Conventional and efficient crosslinking of natural rubber: effect of heterogeneities on the physical properties. KGK Kautsch. Gummi Kunstst. 58, 638–643 (2005).

    Google Scholar 

  51. Yanyo, L. C. Effect of crosslink type on the fracture of natural rubber vulcanizates. Int. J. Fract. 39, 103–110 (1989).

    Article  CAS  Google Scholar 

  52. Cox, W. L. & Parks, C. R. Effect of curing systems on fatigue of natural rubber vulcanizates. Rubber Chem. Technol. 39, 785–797 (1966).

    Article  CAS  Google Scholar 

  53. Wilkinson, B., Ingram, G. D. & Waumsley, H. Manufacture of rubber in sheet or crepe form and of rubber articles. US Patent 2,358,195 (1944).

  54. Rafał Kędzia, J., Maria Sitko, A., Tadeusz Haponiuk, J. & Kucińska Lipka, J. in Application and Characterization of Rubber Materials (eds Evingür, G. A. & Pekcan, Ö.) Ch. 5 (InTechOpen, 2022).

  55. Gent, A. N. Engineering with Rubber: How to Design Rubber Components (Hanser Publishers, 2012).

  56. Candau, N., Chazeau, L., Chenal, J.-M., Gauthier, C. & Munch, E. Compared abilities of filled and unfilled natural rubbers to crystallize in a large strain rate domain. Compos. Sci. Technol. 108, 9–15 (2015).

    Article  CAS  Google Scholar 

  57. Demassieux, Q., Berghezan, D., Cantournet, S., Proudhon, H. & Creton, C. Temperature and aging dependence of strain‐induced crystallization and cavitation in highly crosslinked and filled natural rubber. J. Polym. Sci. B Polym. Phys. 57, 780–793 (2019).

    Article  CAS  Google Scholar 

  58. Creton, C. & Ciccotti, M. Fracture and adhesion of soft materials: a review. Rep. Prog. Phys. 79, 046601 (2016).

    Article  Google Scholar 

  59. Bai, R., Yang, J. & Suo, Z. Fatigue of hydrogels. Eur. J. Mech. 74, 337–370 (2019).

    Article  Google Scholar 

  60. Fleck, N. A., Kang, K. J. & Ashby, M. F. Overview no. 112: the cyclic properties of engineering materials. Acta Metall. Mater. 42, 365–381 (1994).

    Article  CAS  Google Scholar 

  61. Li, C., Yang, H., Suo, Z. & Tang, J. Fatigue-resistant elastomers. J. Mech. Phys. Solids 134, 103751 (2020).

    Article  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Science Foundation under MRSEC (DMR-2011754). Z.S. acknowledges the support of the Air Force Office of Scientific Research under award number FA9550-20-1-0397. M.W.M.T. gratefully acknowledges the financial support under the College of Engineering International Postdoctoral Fellowship, which is jointly provided by the Ministry of Education, Singapore and Nanyang Technological University, Singapore.

Author information

Author notes

  1. These authors contributed equally: Guodong Nian, Zheqi Chen, Xianyang Bao.

Authors and Affiliations

  1. John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA

    Guodong Nian, Zheqi Chen, Xianyang Bao, Matthew Wei Ming Tan & Zhigang Suo

  2. College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China

    Zheqi Chen

  3. School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore

    Matthew Wei Ming Tan

  4. Expert-in-Residence, Office of Technology Development, Harvard University, Cambridge, MA, USA

    Yakov Kutsovsky

Authors
  1. Guodong Nian
    View author publications

    Search author on:PubMed Google Scholar

  2. Zheqi Chen
    View author publications

    Search author on:PubMed Google Scholar

  3. Xianyang Bao
    View author publications

    Search author on:PubMed Google Scholar

  4. Matthew Wei Ming Tan
    View author publications

    Search author on:PubMed Google Scholar

  5. Yakov Kutsovsky
    View author publications

    Search author on:PubMed Google Scholar

  6. Zhigang Suo
    View author publications

    Search author on:PubMed Google Scholar

Contributions

G.N., Z.C. and X.B. conceived the project. G.N., Z.C., X.B. and M.W.M.T. conducted the experiments and analysed the results. Z.S. and Y.K. supervised the research. All the authors designed the study, and wrote and edited the manuscript.

Corresponding author

Correspondence to Zhigang Suo.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Sustainability thanks Costantino Creton and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information (download PDF )

Supplementary Figs. 1–12, Legends for Videos 1–6 and References.

Reporting Summary (download PDF )

Supplementary Video 1 (download MP4 )

Monotonically loading a precracked sample of tanglemer.

Supplementary Video 2 (download MP4 )

Monotonically loading a precracked sample of regular network.

Supplementary Video 3 (download MP4 )

Monotonically loading precracked samples under polarized light.

Supplementary Video 4 (download MP4 )

Stretching various rubbers, holding and then cutting.

Supplementary Video 5 (download MP4 )

Highly stretched tanglemer survives after multiple cutting.

Supplementary Video 6 (download MP4 )

Tanglemer holds the load after suffering a sudden cut.

Source Data for Supplementary Figures (download XLSX )

Source data for supplementary figures.

Source data

Source Data Fig. 1 (download XLSX )

Statistical source data.

Source Data Fig. 3 (download XLSX )

Statistical source data.

Source Data Fig. 4 (download XLSX )

Statistical source data.

Source Data Fig. 5 (download XLSX )

Statistical source data.

Source Data Fig. 6 (download XLSX )

Statistical source data.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Nian, G., Chen, Z., Bao, X. et al. Natural rubber with high resistance to crack growth. Nat Sustain 8, 692–701 (2025). https://doi.org/10.1038/s41893-025-01559-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Version of record:

  • Issue date:

  • DOI: https://doi.org/10.1038/s41893-025-01559-z

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing