Chain rupture during tensile deformation of nylon 6 fibers

Abstract

By simultaneous recording of tensile stress-strain data and the free radicals formed during bond rupture, new knowledge is obtained of the molecular mechanism of deformation and fracture of oriented fibers. To do this, a large variation in molecular morphology was obtained by strain annealing nylon 6 fibers at various temperatures and tensions. The results show that in order to maximize fracture stress, it is necessary to break some chains during the annealing treatment. Tension will overcome the detrimental changes caused by high temperature; if sufficiently high tension is applied, higher strengths are obtained. It is also found that the initial rupture of chains will be later when the chains are more homogeneous and are able to absorb and distribute the stress more uniformly. This homogeneous stress distribution leads to stronger fibers.