Enhanced Mechanical Endurance of Internally Cross-Linked Polymers
Understanding how materials are affected by mechanical stress is central for developing novel and robust materials with extended lifetimes. In this regard, the most fundamental process is the effect of mechanical stress on molecules, where mechanical energy is transduced into chemical energy by scission of chemical bonds, a process called mechanochemistry1,2. The accumulation of stress at specific locations in the polymer chain is known mainly for two polymeric architectures - linear and cross-linked. In our research we exploit a novel architecture in which linear polymers are intramolecularly cross-linked, forming Single Chain Polymer Nanoparticle (SCPN). Our study shows that whereas linear polymer chains undergo fast degradation under the influence of mechanical force, SCPNs derived from the same linear chains demonstrate high endurance. In addition, we studied how different parameters affect the mechanical stability such as molecular weight, cross-link density and side-chain length, and with the help of ultra-high Mw polymers, are able to observe the scission of intramolecular cross-links and therefore redirection of the mechanical force from the polymer main chain.
(1) Caruso, M. M.; Davis, D. A.; Shen, Q.; Odom, S. A.; Sottos, N. R.; White, S. R.; Moore, J. S. Chemical Reviews 2009, 109, 5755.
(2) May, P. A.; Moore, J. S. Chemical Society Reviews 2013, 42, 7497.
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