Molecular stress relief through a force-induced irreversible extension in polymer contour length.
Single-molecule force spectroscopy is used to observe the irreversible extension of a gem-dibromocyclopropane (gDBC)-functionalized polybutadiene under tension, a process akin to polymer necking at a single-molecule level. The extension of close to 28% in the contour length of the polymer backbone occurs at roughly 1.2 nN (tip velocity of 3 μm/s) and is attributed to the force-induced isomerization of the gDBCs into 2,3-dibromoalkenes. The rearrangement represents a possible new mechanism for localized stress relief in polymers and polymer networks under load, and the quantification of the force dependency provides a benchmark value for further studies of mechanically triggered chemistry in bulk polymers.
Department of Chemistry and Center for Biologically Inspired Materials and Material Systems, Duke University, Durham, North Carolina 27708-0346, United States.
Dong
D
Wu
Jeremy M
JM
Lenhardt
Ashley L
AL
Black
Boris B
BB
Akhremitchev
Stephen L
SL
Craig
D002070:Butadienes / Q000737:chemistry*; D003521:Cyclopropanes / Q000737:chemistry*; D020724:Elastomers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D013314:Stress, Mechanical
D002070:Butadienes; D003521:Cyclopropanes; D020724:Elastomers; C556059:gem-dibromocyclopropane; C028834:polybutadiene