Chain mobility in the amorphous region of nylon 6 observed under active uniaxial deformation

A specially designed solid-state deuterium nuclear magnetic resonance probe was used to examine the effect of uniaxial elongation on the chain mobilit y in the amorphous region of semicrystalline nylon 6. In measurements condu cted near the glass transition temperature, there was measurable deformatio n-induced enhancement of the mobility of the amorphous chains up to the yie ld point. This enhanced mobility decayed once deformation was stopped. Enha nced mobility was not observed in deformation at room temperature. The mech anics of deformation can be explained by the Robertson model for glassy pol ymers near the glass transition temperature, which states that applied stre ss induces liquid-like behavior in the polymer chains.