A Biomimetic Approach to Polymer Solutions with Enhanced Mechanochemical Stability

Polymer materials suffer from loss of physical properties when absorbing mechanical energy, as this energy is transduced into chain fragmentation and reduction of Mw, in a process called mechanochemistry¹. Mechanochemical events are known to occur faster in longer polymer chains², thus it is surprising that the molecular spring in the muscles, the gigantic protein Titin, absorbs mechanical energy without undergoing fragmentation. Inspired by Titin’s structure, we have recently demonstrated that addition of intramolecular cross-links to synthetic polymers significantly improves their mechanochemical stability in solution³. Hence, we are conducting a thorough study to better understand the role of the cross-links in the mechanochemical response of covalent macromolecules. The cross-link density and length, as well as the polymer length are all varied in order to understand their effect on the polymer stability. Moreover, we were able to obtain insights into the mechanochemical mechanism when testing ultra-high Mw polymers and spin-traps. Our findings suggest that polymers with intramolecular cross-links are promising candidates for the development of viscosity index modifiers, given their enhanced mechanochemical stability, and this capability is demonstrated by conducting experiments in polymer solutions in oil.

[1] M. M. Caruso, D. A. Davis, Q. Shen, S. A. Odom, N. R. Sottos, S. R. White, J. S. Moore, Chem. Rev. 2009, 109, 5755-5798.

[2] P. A. May, N. F. Munaretto, M. B. Hamoy, M. J. Robb, J. S. Moore, ACS Macro Lett. 2016, 177-180.

[3] A. Levy, F. Wang, A. Lang, O. Galant, C. E. Diesendruck, Angew. Chem. Int. Ed. 2017, 129, 6531-6534.