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Mechanically controlled radical polymerization initiated by ultrasound


In polymer chemistry, mechanical energy degrades polymeric chains. In contrast, in nature, mechanical energy is often used to create new polymers. This mechanically stimulated growth is a key component of the robustness of biological materials. A synthetic system in which mechanical force initiates polymerization will provide similar robustness in polymeric materials. Here we show a polymerization of acrylate monomers initiated and controlled by mechanical energy provided by ultrasonic agitation. The activator for an atom-transfer radical polymerization is generated using piezochemical reduction of a Cu(II) precursor complex, which thus converts a mechanical activation of piezoelectric particles to the synthesis of a new material. This polymerization reaction has some characteristics of controlled radical polymerization, such as narrow molecular-weight distribution and linear dependence of the polymeric chain length on the time of mechanical activation. This new method of controlled radical polymerization complements the existing methods to synthesize commercially useful well-defined polymers.

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Figure 1: Ultrasound-induced controlled radical polymerization of n-butyl acrylate 1.
Figure 2: Analysis of the piezoelectric reaction and evidence for reduction and initial polymerization.
Figure 3: Potential mechanisms for the ultrasound-mediated generation of ATRP activator.
Figure 4: Polymerization kinetics in control experiments reveal that continuous ultrasonic agitation is necessary for a growing polymer chain.


  1. 1

    Chen, J.-H., Liu, C., You, L. & Simmons, C. A. Boning up on Wolff's Law: mechanical regulation of the cells that make and maintain bone. J. Biomech. 43, 108–118 (2010).

    Article  Google Scholar 

  2. 2

    Christen, P. et al. Bone remodelling in humans is load-driven but not lazy. Nat. Commun. 5, 4855 (2014).

    CAS  Article  Google Scholar 

  3. 3

    Li, J., Nagamani, C. & Moore, J. S. Polymer mechanochemistry: from destructive to productive. Acc. Chem. Res. 48, 2181–2190 (2015).

    CAS  Article  Google Scholar 

  4. 4

    Brown, C. L. & Craig, S. L. Molecular engineering of mechanophore activity for stress-responsive polymeric materials. Chem. Sci. 6, 2158–2165 (2015).

    CAS  Article  Google Scholar 

  5. 5

    Larsen, M. B. & Boydston, A. J. Investigations in fundamental and applied polymer mechanochemistry. Macromol. Chem. Phys. 217, 354–364 (2016).

    CAS  Article  Google Scholar 

  6. 6

    Piermattei, A., Karthikeyan, S. & Sijbesma, R. P. Activating catalysts with mechanical force. Nat. Chem. 1, 133–137 (2009).

    CAS  Article  Google Scholar 

  7. 7

    White, S. R. et al. Autonomic healing of polymer composites. Nature 409, 794–797 (2001).

    CAS  Article  Google Scholar 

  8. 8

    Xia, Y. & Whitesides, G. M. Soft lithography. Angew. Chem. Int. Ed. 37, 550–575 (1998).

    CAS  Article  Google Scholar 

  9. 9

    Diesendruck, C. E., Sottos, N. R., Moore, J. S. & White, S. R. Biomimetic self-healing. Angew. Chem. Int. Ed. 54, 10428–10447 (2015).

    CAS  Article  Google Scholar 

  10. 10

    Dong, P. et al. Solid–liquid self-adaptive polymeric composite. ACS Appl. Mater. Interfaces 8, 2142–2147 (2016).

    CAS  Article  Google Scholar 

  11. 11

    Leibfarth, F. A., Mattson, K. M., Fors, B. P., Collins, H. A. & Hawker, C. J. External regulation of controlled polymerizations. Angew. Chem. Int. Ed. 52, 199–210 (2013).

    CAS  Article  Google Scholar 

  12. 12

    Ogawa, K., Goetz, A. & Boydston, A. Developments in externally regulated ring-opening metathesis polymerization. Synlett 27, 203–214 (2016).

    CAS  Google Scholar 

  13. 13

    Kean, Z. S. & Craig, S. L. Mechanochemical remodeling of synthetic polymers. Polymer 53, 1035–1048 (2012).

    CAS  Article  Google Scholar 

  14. 14

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

    CAS  Article  Google Scholar 

  15. 15

    Matyjaszewski, K. & Spanswick, J. Controlled/living radical polymerization. Mater. Today 8, 26–33 (2005).

    CAS  Article  Google Scholar 

  16. 16

    Matyjaszewski, K. & Xia, J. Atom transfer radical polymerization. Chem. Rev. 101, 2921–2990 (2001).

    CAS  Article  Google Scholar 

  17. 17

    Jakubowski, W. & Matyjaszewski, K. Activator generated by electron transfer for atom transfer radical polymerization. Macromolecules 38, 4139–4146 (2005).

    CAS  Article  Google Scholar 

  18. 18

    Tasdelen, M. A., Uygun, M. & Yagci, Y. Photoinduced controlled radical polymerization in methanol. Macromol. Chem. Phys. 211, 2271–2275 (2010).

    CAS  Article  Google Scholar 

  19. 19

    Magenau, A. J. D., Strandwitz, N. C., Gennaro, A. & Matyjaszewski, K. Electrochemically mediated atom transfer radical polymerization. Science 332, 81–84 (2011).

    CAS  Article  Google Scholar 

  20. 20

    Hong, K.-S., Xu, H., Konishi, H. & Li, X. Direct water splitting through vibrating piezoelectric microfibers in water. J. Phys. Chem. Lett. 1, 997–1002 (2010).

    CAS  Article  Google Scholar 

  21. 21

    Wang, X., Song, J., Liu, J. & Wang, Z. L. Direct-current nanogenerator driven by ultrasonic waves. Science 316, 102–105 (2007).

    CAS  Article  Google Scholar 

  22. 22

    Qin, Y., Wang, X. & Wang, Z. L. Microfibre–nanowire hybrid structure for energy scavenging. Nature 451, 809–813 (2008).

    CAS  Article  Google Scholar 

  23. 23

    Wang, Z. L. & Song, J. Piezoelectric nanogenerators based on zinc oxide nanowire arrays. Science 312, 242–246 (2006).

    CAS  Article  Google Scholar 

  24. 24

    Starr, M. B. & Wang, X. Coupling of piezoelectric effect with electrochemical processes. Nano Energy 14, 296–311 (2015).

    CAS  Article  Google Scholar 

  25. 25

    Hong, K.-S., Xu, H., Konishi, H. & Li, X. Piezoelectrochemical effect: a new mechanism for azo dye decolorization in aqueous solution through vibrating piezoelectric microfibers. J. Phys. Chem. C 116, 13045–13051 (2012).

    CAS  Article  Google Scholar 

  26. 26

    Qiu, J., Matyjaszewski, K., Thouin, L. & Amatore, C. Cyclic voltammetric studies of copper complexes catalyzing atom transfer radical polymerization. Macromol. Chem. Phys. 201, 1625–1631 (2000).

    CAS  Article  Google Scholar 

  27. 27

    Krys, P., Ribelli, T. G., Matyjaszewski, K. & Gennaro, A. Relation between overall rate of ATRP and rates of activation of dormant species. Macromolecules 49, 2467–2476 (2016).

    CAS  Article  Google Scholar 

  28. 28

    Haas, I. & Gedanken, A. Sonoelectrochemistry of Cu2+ in the presence of cetyltrimethylammonium bromide: obtaining CuBr instead of copper. Chem. Mater. 18, 1184–1189 (2006).

    CAS  Article  Google Scholar 

  29. 29

    Chou, H. C. J. & Stoffer, J. O. Ultrasonically initiated free radical-catalyzed emulsion polymerization of methyl methacrylate (i). J. Appl. Poly. Sci. 72, 797–825 (1999).

    CAS  Article  Google Scholar 

  30. 30

    Paulusse, J. M. J. & Sijbesma, R. P. Ultrasound in polymer chemistry: revival of an established technique. J. Polym. Sci. A 44, 5445–5453 (2006).

    CAS  Article  Google Scholar 

  31. 31

    Alexander, P. & Fox, M. The role of free radicals in the degradation of high polymers by ultrasonics and by high-speed stirring. J. Polym. Sci. 12, 533–541 (1954).

    CAS  Article  Google Scholar 

  32. 32

    Henglein, V. A. Die Bildung von Graftpolymeren aus Polyacrylamid und Acrylnitril unter dem Einfluß von Ultraschallwellen. Makromol. Chem. 14, 128–145 (1954).

    CAS  Article  Google Scholar 

  33. 33

    Bartsch, A. & Schmidt-Naake, G. N-Oxyl-controlled radical copolymerization of styrene with ethyl α-cyanocinnamate. Macromol. Chem. Phys. 205, 1519–1524 (2004).

    CAS  Article  Google Scholar 

  34. 34

    Ramirez, A. L. B. et al. Mechanochemical strengthening of a synthetic polymer in response to typically destructive shear forces. Nat. Chem. 5, 757–761 (2013).

    CAS  Article  Google Scholar 

  35. 35

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

    CAS  Article  Google Scholar 

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SEM work was performed at the Laboratory for Electron and X-ray Instrumentation (LEXI) at UC Irvine, using instrumentation funded in part by the National Science Foundation Center for Chemistry at the Space-Time Limit (CHE-082913). A.P.E.K. acknowledges an AFOSR Young Investigator Grant under FA9550-12-1-0352, FA9550-15-1-0300 and FA9550-16-1-0017, a 3M Non-Tenured Faculty award and a DARPA Young Faculty Award for support. M.K. acknowledges the Israeli council for higher education for support.

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H.M., A.P.E.-K. and M.K. conceived and designed the experiments. H.M. and M.K. performed the experiments. M.K. performed the electron microscopy experiments. All the authors analysed the results and co-wrote the manuscript.

Corresponding author

Correspondence to Aaron Palmer Esser-Kahn.

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The authors declare no competing financial interests.

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Mohapatra, H., Kleiman, M. & Esser-Kahn, A. Mechanically controlled radical polymerization initiated by ultrasound. Nature Chem 9, 135–139 (2017).

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