Intensity of the relaxation processes in statically loaded,highly oriented synthetic fibers

An experimental study of the stress relaxation and creep of a series of synthetic fibers has revealed a reduction in the intensity of these processes as the tensile strain increases. On the basis of a comparison of the relations obtained and the results of previous studies of loaded oriented polymers using small-angle x-ray scattering and NMR techniques it is suggested that the observed effect is attributable to orientational ordering of the through macromolecules in the amorphous regions of the fiber. It is also concluded that in oriented polymers at strains considerably below breaking values the elementary relaxation events are physical (and not mechanochemical) in nature.Kirov Leningrad Institute of the Textile and Light Industries. Translated from Mekhanika Polimerov, No. 1, pp. 154–157, January–February, 1973.