Chain Mobility in the Amorphous Region of Nylon 6 Observed under Active Uniaxial Deformation
Leslie S. Loo,
Robert E. Cohen,
Karen K. Gleason
*
A specially designed solid-state deuterium nuclear magnetic
resonance probe was used to examine the effect of uniaxial elongation on the chain mobility in the amorphous region of semicrystalline nylon
6. In measurements conducted near the glass transition temperature, there was measurable deformation-induced enhancement of the mobility of
the amorphous chains up to the yield point. This enhanced mobility decayed once deformation was stopped. Enhanced mobility was not observed in deformation at room temperature. The mechanics of deformation can be explained by the Robertson model for glassy polymers
near the glass transition temperature, which states that applied stress
induces liquid-like behavior in the polymer chains.
Department of Chemical Engineering and Center for Materials
Science and Engineering, Massachusetts Institute of Technology,
Cambridge, MA 02139, USA.
*
To whom correspondence should be addressed. E-mail:
kkgleasn{at}mit.edu
