Effect of alkali treatment on structure of surface layers of elementary polyethylene terephthalate filaments

The change in supermolecular structure of polyethylene terephthalate as a result of hydrolytic degradation of macromolecules in hydrolysis of yarns from Lavsan yarns has been studied by the method of internal reflection IR spectrophotometry. The nonlinear decrease in degree of orientation of macromolecules thereupon has been connected up with a nonlinear decrease in fabric stiffness caused by etching of the surface layer of elementary filaments.