Article | Published:

Mechanically triggered heterolytic unzipping of a low-ceiling-temperature polymer

Nature Chemistry volume 6, pages 623628 (2014) | Download Citation

Abstract

Biological systems rely on recyclable materials resources such as amino acids, carbohydrates and nucleic acids. When biomaterials are damaged as a result of aging or stress, tissues undergo repair by a depolymerization–repolymerization sequence of remodelling. Integration of this concept into synthetic materials systems may lead to devices with extended lifetimes. Here, we show that a metastable polymer, end-capped poly(o-phthalaldehyde), undergoes mechanically initiated depolymerization to revert the material to monomers. Trapping experiments and steered molecular dynamics simulations are consistent with a heterolytic scission mechanism. The obtained monomer was repolymerized by a chemical initiator, effectively completing a depolymerization–repolymerization cycle. By emulating remodelling of biomaterials, this model system suggests the possibility of smart materials where aging or mechanical damage triggers depolymerization, and orthogonal conditions regenerate the polymer when and where necessary.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    , & Biochemistry (W. H. Freeman, 2010).

  2. 2.

    Amino acids: metabolism, functions, and nutrition. Amino Acids 37, 1–17 (2009).

  3. 3.

    Carbohydrate Chemistry and Biochemistry: Structure and Mechanism (Royal Society of Chemistry, 2012).

  4. 4.

    , , & Nucleic Acids in Chemistry and Biology (Royal Society of Chemistry, 2006).

  5. 5.

    et al. Mechanically-induced chemical changes in polymeric materials. Chem. Rev. 109, 5755–5798 (2009).

  6. 6.

    & Polymer mechanochemistry: techniques to generate molecular force via elongational flows. Chem. Soc. Rev. 42, 7497–7506 (2013).

  7. 7.

    , & Controlled depolymerization: stimuli-responsive self-immolative polymers. Macromolecules 45, 7317–7328 (2012).

  8. 8.

    & Self-immolative polymers. Angew. Chem. Int. Ed. 47, 7804–7806 (2008).

  9. 9.

    , , & Self-immolative polymers. J. Am. Chem. Soc. 130, 5434–5435 (2008).

  10. 10.

    Bone resorption by osteoclasts. Science 289, 1504–1508 (2000).

  11. 11.

    , , & Structure and mechanical quality of the collagen–mineral nanocomposite in bone. J. Mater. Chem. 14, 2115–2123 (2004).

  12. 12.

    Normal and pathological remodeling of human trabecular bone: 3-dimensional reconstruction of the remodeling sequence in normals and in metabolic bone-disease. Endocrin. Rev. 7, 379–408 (1986).

  13. 13.

    Osteonal and hemi-osteonal remodeling: the spatial and temporal framework for signal traffic in adult human bone. J. Cell Biochem. 55, 273–286 (1994).

  14. 14.

    , & Polymerization of aromatic aldehydes. II. Cationic cyclopolymerization of phthalaldehyde. J. Polym. Sci. A 7, 497–511 (1969).

  15. 15.

    , , & Acid-catalyzed degradation mechanism of poly(phthalaldehyde): unzipping reaction of chemical amplification resist. J. Polym. Sci. A 35, 77–89 (1997).

  16. 16.

    , & Kinetics of ultrasonic and transient elongational flow degradation: a comparative study. Polymer 38, 3783–3793 (1997).

  17. 17.

    Mechanochemistry: a tour of force. Nature 487, 176–177 (2012).

  18. 18.

    , & Polymer mechanochemistry: force enabled transformations. ACS Macro Lett. 1, 623–626 (2012).

  19. 19.

    , & End group characterization of poly(phthalaldehyde): surprising discovery of a reversible, cationic macrocyclization mechanism. J. Am. Chem. Soc. 135, 12755–12761 (2013).

  20. 20.

    & Single-electron transfer and single-electron transfer degenerative chain transfer living radical polymerization. Chem. Rev. 109, 5069–5119 (2009).

  21. 21.

    et al. Masked cyanoacrylates unveiled by mechanical force. J. Am. Chem. Soc. 132, 4558–4559 (2010).

  22. 22.

    et al. Ionic species produced by mechanical fracture of solid polymer. III. Anions from polytetrafluoroethylene. J. Polym. Sci. B 25, 1431–1437 (1987).

  23. 23.

    et al. Ionic products from the mechanical fracture of solid polypropylene. Polymer 25, 944–946 (1984).

  24. 24.

    , , & Mechanoanions produced by mechanical fracture of bacterial cellulose: ionic nature of glycosidic linkage and electrostatic charging. J. Phys. Chem. A 116, 9872–9877 (2012).

  25. 25.

    & Breaking bonds by mechanical stress: when do electrons decide for the other side? J. Am. Chem. Soc. 124, 3402–3406 (2002).

  26. 26.

    & Sonically induced heterolytic cleavage of polymethylsiloxane. J. Phys. Chem. 63, 253–256 (1959).

  27. 27.

    et al. First principles dynamics and minimum energy pathways for mechanochemical ring opening of cyclobutene. J. Am. Chem. Soc. 131, 6377–6379 (2009).

  28. 28.

    , & Steered molecular dynamics and mechanical function of proteins. Curr. Opin. Struct. Biol. 11, 224–230 (2001).

  29. 29.

    & Quantum chemistry on graphical processing units. 3. Analytical energy gradients, geometry optimization, and first principles molecular dynamics. J. Chem. Theor. Comp. 5, 2619–2628 (2009).

  30. 30.

    Density functional thermochemistry. III. The role of exact exchange. J. Chem. Phys. 98, 5648–5652 (1993).

  31. 31.

    , & Development of the Colle–Salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B 37, 785–789 (1988).

  32. 32.

    , & Self-consistent molecular orbital methods. XII. Further extensions of Gaussian-type basis sets for use in molecular orbital studies of organic molecules. J. Chem. Phys. 56, 2257–2261 (1972).

  33. 33.

    , & Reproducible and scalable synthesis of end-cap-functionalized depolymerizable poly(phthalaldehydes). Macromolecules 46, 2963–2968 (2013).

  34. 34.

    The estimation of mechanical properties of polymers from molecular structure. J. Appl. Polym. Sci. 49, 1331–1351 (1993).

Download references

Acknowledgements

This material is based on work supported by the Air Force Office of Scientific Research Discovery Program (grant no. 392 AF FA9550-10-1-0255), the National Science Foundation (CHE-1300313), the US Army Research Laboratory, the US Army Research Office (grant no. W911NF-07-1-0409) and the Department of Defense (Office of the Assistant Secretary of Defense for Research and Engineering) through an NSSEFF fellowship. J.A.K. acknowledges the Springborn Endowment for a graduate fellowship and funding for materials as part of the Center for Electrical Energy Storage, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences (award no. DOE ANL 9F-31921J). G.I.P. and A.J.B. acknowledge support from the University of Washington, University of Washington Royalty Research Fund, and US Army Research Office Young Investigator Program (grant no. W911NF-11-1-0289). H.J.K. holds a Career Award at the Scientific Interface from the Burroughs Wellcome Fund.

Author information

Author notes

    • Heather J. Kulik

    Present address: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachussetts 02139, USA

Affiliations

  1. Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA

    • Charles E. Diesendruck
    • , Joshua A. Kaitz
    • , Preston A. May
    •  & Jeffrey S. Moore
  2. Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA

    • Charles E. Diesendruck
    • , Preston A. May
    • , Scott R. White
    •  & Jeffrey S. Moore
  3. Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA

    • Scott R. White
  4. Department of Chemistry, University of Washington, Seattle, Washington 98195, USA

    • Gregory I. Peterson
    •  & Andrew J. Boydston
  5. Department of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, USA

    • Heather J. Kulik
    • , Brendan D. Mar
    •  & Todd J. Martínez
  6. SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA

    • Todd J. Martínez

Authors

  1. Search for Charles E. Diesendruck in:

  2. Search for Gregory I. Peterson in:

  3. Search for Heather J. Kulik in:

  4. Search for Joshua A. Kaitz in:

  5. Search for Brendan D. Mar in:

  6. Search for Preston A. May in:

  7. Search for Scott R. White in:

  8. Search for Todd J. Martínez in:

  9. Search for Andrew J. Boydston in:

  10. Search for Jeffrey S. Moore in:

Contributions

J.S.M., T.J.M., A.J.B. and S.R.W. directed the research. J.S.M., A.J.B., C.E.D. and P.A.M. conceived the idea. C.E.D., G.I.P., J.A.K. and P.A.M. performed the experiments. H.J.K. and B.D.M. conducted the theoretical studies. All authors participated in writing the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Jeffrey S. Moore.

Supplementary information

PDF files

  1. 1.

    Supplementary information

    Supplementary information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nchem.1938

Further reading