Study on the Structure and the Physical Properties of Synthetic Fibers Treated with Organic Solvents(IV) - The Change of Mechanical Properties by Redrawing of Nylon 6 Filament Shrunken with Formic Acid-

용제처리에 의한 합성섬유의 구조와 물성에 관한 연구(IV) -Formic Acid 처리로 수축된 Nylon 6 Filament의 재연신에 의한 기계적 성질변화-

High-tenacity nylon 6 filaments were shrunken by aqueous solution of 60% formic acid and redrawn with various extents(recovery ratio for shrunken portion : 20, 40, 60, 80, 100%) at various temperatures(50,70,90,16$0^{\circ}C$), and some of redrawn filaments were heat-treated. And then the change of mechanical properties and the relationship between structure and mechanical droperties were investigated chiefly. Tensile strength, initial modulus, and temperatures of maximum tan$\delta$ peak were decreased with redraw ratio ; the tendencies of those changes were larger in the case of hear-treatment than that of nonheat-treatment generally ; especially the increasing tendency of initial modulus was largest in the case of redrawing at 16$0^{\circ}C$. Most of the changes might be largely affected by orientation, more particularly amorphous orientation, in addition to it the initial modulus and elongation might be affected also by the fraction of taut tie molecule, the long period and potentiality for unfolding of folded chains in crystalline region, respectively. The dependence of most changes of mechanical properties upon the redraw temperatures was indicated little at the lower ones(50,70, and 9$0^{\circ}C$)